30 Grosvenor Square

Heritage Statement 30 Grosvenor Square

Applications for Amendments to Planning Permission and Listed Building Consent (s.73 & s.19): Lighting, façade restoration and cleaning.

October 2020

Contents

1. Introduction 1

2. The Heritage Asset – 30 Grosvenor Square 2

3. Proposed Amendments 7

4. Impact Assessment 11

5. Conclusion 15

Appendix 1: Statement of Significance: Former United States of America Embassy, Grosvenor Square (Grade II listed building) 16

Appendix 2: Policy, Guidance and Advice: Lighting Historic Buildings (extracts) 55

Our reference QATN3001

October 2020

1. Introduction

Background

1.1 Listed building consent and planning permission are sought for Amendments to the previously consented proposals (the ‘Approved Scheme’).

1.2 The Amendments comprise:

a. Installation of external lighting on all façades of the building, uplighting to the Eagle sculpture and installation of lighting within the landscape including uplighting to trees and building columns;

b. Careful temporary removal and storage of the existing column stone cladding and end caps on all façades to facilitate construction works, with material proposed to be securely re-instated with mechanical fixtures; and

c. Proposed cleaning of all existing Portland stone that has been retained, including the reinstated stone cladding of the cruciform columns.

1.3 This document acts as an addendum to the original Heritage, Townscape and Visual Impact Assessment (HTVIA) that supported applications 16/06423/FULL and 16/06463/LBC and to the subsequent addendum document, which supported applications 18/03520/FULL and 18/03517/LBC (as amended).

1.4 The requirement for this assessment derives from the Planning (Listed Buildings and Conservation Areas) Act 1990 that places a duty upon the local planning authority in determining applications for development affecting listed buildings to pay special regard to the desirability of preserving the building or its setting.

1.5 The National Planning Policy Framework (NPPF) provides the Government’s national planning policy on the conservation of the historic environment. In respect of information requirements for applications, it requires that:

“In determining applications, local planning authorities should require an applicant to describe the significance of any heritage assets affected, including any contribution made by their setting. The level of detail should be proportionate to the assets’ importance and no more than is sufficient to understand the potential impact of the proposal on their significance”1

1.6 The nature and extent of the significance in terms of special interest of the listed building, the contribution of setting and the significance of the wider Mayfair Conservation Area and adjacent Grosvenor Square registered park and garden were fully assessed to support the previously consented applications.

1.7 For ease of reference, the full assessment of the significance of the listed building is set out in Appendix 1 drawn from the Heritage Townscape and Visual Impact Assessment (HTVIA) which supported the previous applications.

1 National Planning Policy Framework (NPPF) 2019

2. The Heritage Asset – 30 Grosvenor Square

Introduction

2.1 The former United States of America Embassy (30 Grosvenor Square) was added at grade II to the statutory list of buildings of special architectural or historic interest on 21st October 2009. The building was built 1957-60 to the design of Eero Saarinen assisted by Yorke, Rosenberg and Mardell as UK executive architects; F J Samuely were the structural engineers; and, the Eagle statue was by Theodore Roszac.

2.2 The building is located on the west side of Grosvenor Square, with shorter return elevations to the north and south set back from the street, from which it was separated by a stone faced glacis. The building has a symmetrical ‘U’ shaped plan, comprising a raised ground floor with central main entrance and lobby with large halls to either side, leading through to single storey offices.

2.3 Separate entrances to the former Consular and Information Sections are on the north and south sides, each with a lobby and stair to either side. The basement comprised a café and auditorium and the upper floors were cellular offices.

2.4 Constructed of reinforced concrete clad in Portland stone on the front and side elevations and concrete to the rear, the long tripartite façade comprises 22 bays with 5 bay entrance and tall recessed ground floor supported on cruciform columns, with 4 floors and set back attic storey above.

2.5 These upper floors are carried on a giant concrete ‘diagrid’ floor of intersecting diagonal concrete beams the exposed ends of which enable the façade to overhang the column line. Several external elements including the exposed ends to the structural diagrid were clad with aluminium.

2.6 The full history, development and resultant significance of the building in terms of special architectural or historic interest is set out in Appendix 1 to this Addendum.

Summary of Heritage Significance

2.7 For national planning policy purposes, heritage significance is defined2 “as the value of a heritage asset to this and future generations because of its heritage interest. That interest may be archaeological, architectural, artistic or historic. Significance derives not only from a heritage asset’s physical presence, but also from its setting”.

2.8 The grade II listed former Embassy building is a designated heritage asset3 and significance as a listed building derives from special architectural or historic interest4.

2.9 The list entry description whilst prepared before the provisions of the Enterprise and Regulatory Reform Act 2013, is nevertheless clear regarding the reasons for listing of

2 NPPF Annex 2 Glossary 3 Ibid 4 Section 1 Planning (Listed Buildings and Conservation Areas) Act 1990

the building and precise regarding the nature and extent of special interest. Subsequent visits to the building by Historic England’s listing team5 did not highlight any other substantive areas of perceived interest within the building to those noted at the time of listing.

2.10 Notably, at the time of listing English Heritage (now Historic England) stated6:

“The special architectural interest of this building lies primarily in its strongly- articulated design and dynamic facades. The design employs an innovative application of exposed concrete diagrid. The internal interest of the embassy is largely confined to the ground floor, the ceilings echo the diagrid formula of the building’s façade and the central lobby is clad in Greek Pentelicon marble. This constructional form (of unusual sophistication in 1950s Britain, showing the technological prowess then associated with the United States) is one of the building’s principal features, expressed externally and internally and echoed in details such as the gilded pressed-metal parapet and the cog- wheel window motifs and exposed beam ends.”

2.11 A full assessment of the significance of the listed building is set out in Appendix 1 drawn from the Heritage Townscape and Visual Impact Assessment (HTVIA) which supported the previous applications. In summary:

Special Architectural Interest:

 Strongly articulated design and dynamic facades with well-detailed stonework and consistency of detail;

 Of particular note, the exposed concrete diagrid – an intelligent combination of structural expression and decorative motif, provides cohesion to the whole and illustrates architect’s principles of marrying from to structure, interior to exterior, and his close involvement in detail and execution;

 Building designed by Eero Saarinen - an outstanding figure in C20th architecture and design – and provides early example of a modernist yet contextual approach to design in a sensitive urban location; Eagle statue by Theodore Roszac, noted Polish-American sculptor. Executive UK architects Yorke, Rosenberg and Mardell and F J Samuely structural engineers (Frank Newby);

 Internal interest (confined to ground floor public spaces): main entrance and central lobbies, passport office and former library (with cruciform columns) and former information service and consular lobbies and stairs where the diagrid is exposed throughout. The most notable area is the central lobby clad in Greek Pentelicon marble.

5 April 2015 6 English Heritage press release 22nd October 2009

Special Historic Interest:

 Strong associations with Grosvenor Square (home of first United States Ambassador to this country (No.9) and nerve centre for American Armed Forces and headquarters for General Eisenhower in Great Britain in World War II (No.20) – commemorated by monuments (gardens re-planned in memory of F D Roosevelt, grade II listed statue of Roosevelt).

 Britain’s first modern embassy building – international significance as the apotheosis of United States post-war embassy building programme; only one the result of architectural competition; exemplifies United States post-war mission to engender good will to host nations and buildings that harmonise with surroundings yet distinguishably American and accessible.

 Embodying the special relationship between the United States and United Kingdom also a target for anti-US sentiment – most famously in 1968 anti- Vietnam war demonstrations.

2.12 Noting that external architectural interest diminishes with the rear elevations, which are clad in concrete rather than stone, with the two wings infilled a lower single storey block with service bays beneath, added in place of the originally intended open courtyard in order to provide more office space.

2.13 Internally, whilst interest is confined to the ground floor public spaces, other than the central lobby, the associated spaces rely upon the diagrid ceiling and cruciform columns for interest, although the stairs to north and south lobbies have gilded cruciform balusters.

2.14 The floors above are, and always were, of little distinction and have been much altered reflecting the consulate nature of the building, where most of its functions were routine and administrative. The basement (previously the Embassy café and auditorium) is similarly noted as altered by the time of listing.

Mayfair Conservation Area

2.15 The Mayfair Conservation Area provides the wider setting for the former Embassy building and was first designated in 1969; extended in 1974 to include areas to the south and east of Berkeley Square and east of Savile Row; in1979 to include the area from the north end of South Molton Street to North Audley Street and small extensions on Park Lane; and extended again in 1990 to include small areas on Park Lane and Oxford Street7.

Grosvenor Square Registered Park and Garden of Historic Interest

2.16 Grosvenor Square was registered as a grade II park or garden of historic interest by English Heritage (now Historic England) on 1st October 1987 as an early C18th town square, redeveloped in the C19th and C20th. The register entry was written in 2000 and amended in January and August 2003 and is included in full at Appendix 2. The

7 Mayfair Conservation Area Audit, WCC, May 2004

significance, in terms of historic interest of the registered park and garden is considered in the next sections.

Other nearby Heritage Assets

2.17 Within the vicinity of the former Embassy building are a number of other listed buildings the setting of which comprises the wider Mayfair Conservation Area and Grosvenor Square registered park and garden. For completeness these include:

 Statue of President Roosevelt in centre of Square gardens (grade II);  Eagle Squadron Memorial in Square gardens (grade II);  Police Public Callbox North East of American Embassy (grade II) (relocated);  53 Upper Brook Street (grade II); end of terrace house 1730, altered c.1822-27;  52 Upper Brook Street (grade II); terrace house 1730 with early C19th and C20th alterations;  7 Upper Brook Street (grade II); terraced house 1732 late C19th alterations;  3 Upper Brook Street (grade II); terraced town house 1730 with early and mid C19th alterations;  22 and 23 Grosvenor Square (and 43 North Audley Street) (grade II); town mansion 1906-07;  9 Grosvenor Square (grade II); corner terraced town house c.1725, alterations C19th and C20th (residence of John Adams, first US Ambassador to the Court of St James 1785-88);  80 Brook Street (grade II*); terraced town house 1725, alterations 1822-24 and 1909-10;  4 Grosvenor Square (grade II); terraced town house 1865-68;  38 Grosvenor Square (grade II*); terraced town house c.1727, remodelled 1776, refaced 1854-55;  48 Upper Grosvenor Street (grade II); terraced house 1727-29, early C19th attic storey;  45 Upper Grosvenor Street (grade II); terraced town house one of pair with No.44 1727-30, heightened C19th;  44 Upper Grosvenor Street (grade II); terraced town house one of pair with No.44 1727-30, heightened C19th;  7 Upper Grosvenor Street (grade II); terraced town house c.1729, early C19th facing; and,  6 Upper Grosvenor Street (grade II); end of terrace town house 1825-26.

Contribution of Setting to Significance

2.18 The heritage setting of the various heritage assets overlaps comprising the surroundings from which they are experienced, including the public realm. Guidance

on heritage setting matters is clear that its extent is not fixed and may change as the asset and its surroundings evolve. Elements of setting may make a positive or negative contribution to the significance of an asset, may affect the ability to appreciate that significance or may be neutral. Setting in urban areas, given the number and proximity of heritage assets as is the case here, is intimately linked to considerations of townscape and urban design and of the character and appearance of conservation area.

3. Proposed Amendments

Installation of external lighting

3.1 A carefully considered lighting proposal has been prepared by Lighting Design International ltd (LDI), working in collaboration with David Chipperfield Architects (DCA) and the wider design team to deliver an appropriate and sensitive approach to lighting the listed building.

3.2 The application documents set out the specifications for the luminaires, their mounting details and location together with details of control and operation.

3.3 A range of luminaire types are proposed to be installed to illuminate architectural elements of the facades; the reinstated Eagle sculpture; new canopies and handrails; reinstated and new lighting columns; the 7th floor terrace; and, directional uplighters to the trees (see Luminaire Specification Document prepared by LDI).

Extract from LDI Exterior Lighting Concept document

3.4 The proposals for lighting comprise (see all LDI and DCA documents, drawings and plans):

1. recessed uplighting to columns;

2. downlighting to mullions;

3. backlit glass within entrance canopies;

4. refurbished existing lighting posts;

5. new lighting posts to corners of site;

6. recessed uplighting to trees;

7. small custom made window reveal lights;

8. uplighting to the Eagle sculpture; and,

9. uplighting to columns and gentle wash up back wall on the 7th roof terrace.

3.5 The general approach taken to façade lighting (see LDI Exterior Lighting Concept) is to conceal light fixtures wherever possible and use small/compact fixtures with finishes to match background of façade. No light fixtures will project above the top of the building and cables and connection/control gear boxes will be hidden from view. Light fixtures will be mounted in a manner sensitive to the fabric of the building.

3.6 The aim of the proposals is enhance the architecture and architectural features in an a manner appropriate for the building using techniques and lighting that will not cause glare to users of the building or neighbouring properties. Architectural light fixtures which use controlled optics to minimise stray light are specified, with an intelligent control system to control the hours of operation and power consumption. The lighting levels can be finely adjusted using energy efficient and long-lasting light sources. The colour temperature and rendering index will be sympathetic and specific to the building and its setting. All fixtures and controls are located where they can be easily and safely maintained.

3.7 Importantly, no light fittings will be fixed directly to the existing retained Portland stonework of the facades. Instead, the opportunity is taken to integrate/fix luminaires to the frames of new fenestration, matching their finish. New luminaires are proposed to be accommodated in the existing refurbished and the new replica light columns with new lighting accommodated in fixtures to the ends of the exposed diagrid. Directional lighting of the reinstated Eagle sculpture will be installed at the new 7th floor. Also at 7th floor linear lighting will be concealed at skirting level on the new terraces together with lights within the terrace planting.

3.8 Uplighters will be integrated into new hardsurfacing/landscaping (with uplighting of trees) and downlighters within the panels to the new entrance canopies. Lighting will also be integrated within handrails to the entrances.

3.9 A provisional lighting control strategy is set out at this stage comprising an automatic pre-set dimming control system where different lighting scenes may be selected at different times of the day. The lighting will be ‘tuneable’ to set an appropriate brightness and colour temperature for the building and its immediate setting and public realm.

Amendments to retained façade

3.10 It is proposed to carefully remove and store the existing stone cladding to the cruciform columns and end caps to all retained façades to facilitate construction works, with more secure re-instatement with improved mechanical fixtures.

3.11 During the course of the enabling works to implement the Approved Scheme various surveys and investigations revealed more detail about the construction and condition

of the existing façade. Until this time it was difficult to sufficiently investigate the building due to its former use as the United States London Embassy.

3.12 It was agreed with officers at Westminster City Council to undertake detailed investigations of the cruciform columns to understand the durability and condition of the mechanical fixings, which hold the Portland stone cladding in place. The results of this survey revealed only one pin fixing for each large piece of stone. In turn it was found that these had become loose or disengaged in many of the places.

3.13 It was found that the cladding with the inadequate fixings is located at the jambs to the ‘O’-frames and the stone installed at the tips of the cruciform columns – all being installed with the same method of a strap fitted with dowel. Unfortunately, the dowel only effectively engages with the top of the stone. Cramps retaining other elements of the cladding were also found missing or inadequately embedded.

3.14 The Design Team investigated potential solutions to the issues discovered in the surveys and devised a series of strategies. On consideration of the strengths and weaknesses of each option the following strategy is proposed:

 To remove the stone cladding in a holistic and controlled way, to be stored and re-fixed in the same location from which it was removed with new mechanical fixings that are installed to modern regulation standards.

 This option offers the most reassurance that the stone cladding would be robustly reconstructed to last for at least 60 years. The solution would involve intervention to every existing cruciform column (24 stones per column this would mean a total of 1,392 stone cladding units removed carefully). Every stone would be catalogued, surveyed, stored and then supplied to a competent professional stone mason to be installed as part of the main contract works.

 Cleaning and repair of the stone (see below) in situ is recommended to ensure overall consistency and quality of the final refurbished façade.

Extract from DCA Design Statement - Schematic elevation diagram to show the scope of facade restoration works

Façade (stone) cleaning

3.15 It is proposed to carefully clean all existing Portland stone cladding to the retained facades including the reinstated stone cladding of the cruciform columns.

3.16 The best method for cleaning of the Portland stone cladding of the retained elevations of the listed building has been researched and tested by appropriate specialists. Tests were possible on elements of cladding which had been removed from parts of the building being demolished under the Approved Scheme. Two cleaning specifications typically used on historic masonry were tested; a combination of nebulous cleaning, followed by steam cleaning and finally cleaning with chemical detergents; and, the JOS method (using calcite at 35 psi).

3.17 It was found that use of the JOS method (mixture of low pressure air, a little water and a safe inert fine aggregate also known as TORC or VORTEX) was the most effective in removing staining from the Portland stone. Careful and appropriate cleaning of the existing Portland stone cladding (including that to be carefully removed and reinstated on more secure fixtures – above) will significantly improve the appearance of the listed building, enhancing its architectural interest.

3.18 Further tests will be required on other elements of the retained façade to ensure that the cleaning method is appropriate for all areas. Such tests can be the subject of further agreement with the local planning authority.

4. Impact Assessment

Introduction

4.1 The impact of the proposals on the significance of the identified designated heritage assets is assessed in light of their significance outlined in the preceding sections, and also the relevant heritage legislation and national and local policy framework summarised below.

4.2 The statutory duties8 relevant to the application proposals are:-

 to preserve the listed building, its setting and its features of special architectural or historic interest ; and,

 to preserve or enhance the character or appearance of the conservation area.

4.3 In addition, national planning policy9 requires that :-

 great weight is given to the heritage asset’s conservation (paragraph 193);

 the more importance the asset, the greater the weight should be (paragraph 193); and,

 any harm or loss requires clear and convincing justification (paragraph 194).

4.4 Local planning policy in respect of change within the historic environment supports these objectives of primary legislation and national planning policy.

4.5 Specific to the nature of these proposals is local policy and guidance in respect of the lighting of historic buildings. This, together with advice from Historic England on such matters is summarised in Appendix 2 to this Statement.

4.6 The impacts of the amended proposals are considered in light of the nature and extent of special interest and heritage significance, itself based upon detailed understanding of significance summarised in the previous section, and in context of the Approved Scheme.

Context

4.7 The context for the revised proposals is the Approved Scheme which is being implemented.

4.8 The Approved Scheme for adaptive re-use of the former Embassy building for hotel and associated uses was agreed by Westminster City Council (WCC) in determination of the applications for Planning Permission and Listed Building Consent, to cause less than substantial harm to the significance of the listed building. Historic England also

8 s.16(2); s.66(1); and, s.72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990. 9 National Planning Policy Framework, February 2019

concluded that the proposals would cause less than substantial harm to the significance of the listed building. With reference to the Framework WCC concluded such less than substantial harm was outweighed by the public benefits of the proposals as a whole.

Consideration

4.9 The impact of the amended proposals is considered in light of the duties of primary legislation and national and local policy in respect of designated heritage assets and their settings. The planning history of the site and the Approved Scheme provide further context for assessment of relative impacts.

4.10 With respect to the proposed lighting of the listed building the specific policy and guidance of Westminster City Council (Appendix 2) is also taken into account. We have also taken account of the parallel advice from Historic England10.

Lighting 4.11 The lighting scheme involves a range of luminaires selected for their relative location on retained and new elements or within its immediate setting.

4.12 A range of buildings in Mayfair and within Grosvenor Square have been successfully lit and a significant opportunity arises with the implementation of the Approved Scheme for the adaptive re-use of the former American Embassy building to enhance its appearance and contribution to the Square and wider Mayfair Conservation Area.

4.13 Assessment of the proposals for lighting of the listed building can be considered in light of WCC’s ‘The Twelve Principles of Good Exterior Lighting’ (Appendix 2) as follows (largely replicated by Historic England’s associated advice):-

 Only illuminate buildings of architectural interest.

The host building is listed as being of special architectural and historic interest at grade II.

 Lighting should not be used where it may intrude upon residential properties.

The proposals have been carefully designed to ensure that lighting will not affect any residential properties whilst taking the opportunity to accentuate the listed building’s special architectural interest.

 Lighting units should be discreet and should not compromise the architectural integrity of the building.

The lighting units or luminaires have been specifically selected to be of the minimum size possible to ensure they are visually discreet and incorporated within the new fabric of the building.

 Schemes should accord with the special architectural features of the building.

10 External Lighting for Historic Buildings, English Heritage (now Historic England), 2007.

The lighting scheme has been designed to subtly accentuate the architectural interest of the listed building and its setting in Grosvenor Square, highlighting key architectural features and motifs, including the Eagle sculpture.

 Lighting should take account of nearby schemes and have regard to the total lighting effect in the area.

Account has been taken in the design of the lighting scheme of the wider context of Grosvenor Square and other lighting schemes to ensure that the proposals will enhance the appearance of the conservation area.

 Installations should not damage listed buildings.

The lighting installation will be integral to the refurbished and new fabric of the listed building and not be fixed to, or cause damage to, any retained historic fabric.

 Schemes should minimise light pollution and maximise energy efficiency.

The scheme has been designed to ensure that the lighting is sufficient to highlight the architectural interest of the listed building whilst minimising light pollution with the use of modern energy efficient systems.

 The quality and strength of the light should take account of the nature of the building materials to be illuminated.

The lighting scheme has been devised around the desire to highlight the architectural interest of the external elevations of the listed building and takes full account of the Portland stone cladding and detailing.

 Professional advice should be sought from lighting consultants and planners.

Lighting Design International, professional lighting engineers, have designed the scheme in association with David Chipperfield Associates, scheme architects for the redevelopment of 30 Grosvenor Square.

 Management and maintenance programmes should be devised to ensure consistent and continued lighting display.

A full management and maintenance programme will be devised so that the lighting scheme remains appropriate to the listed building and its new use as a luxury hotel.

 Schemes should be an integral part of new developments.

The lighting scheme has been specifically devised as part of the refurbishment, reconstruction and extension of the listed building allowing it to be fully integrated into new fabric.

 Planning and listed building consents should be sought where necessary.

Applications for minor amendment to both planning permission and listed building consent are sought.

4.14 The luminaires will be of a discreet nature and have been selected for their specific location and role in adequately lighting key architectural features of the building and elements of its setting. The luminaires are as small as possible, discreetly located and/or integrated into refurbished and new features.

4.15 Subtle lighting of the building’s immediate setting is integral to the overall lighting scheme and appropriate to its location in Grosvenor Square, the Mayfair Conservation Area and the setting of other listed buildings.

4.16 Lighting of the exterior of the listed building will realise the opportunity of better revealing its architectural interest and role within Grosvenor Square and the Mayfair Conservation Area. The overall lighting scheme is well designed and co-ordinated and appropriate to the scale of the building and its setting, drawing attention to the building’s architectural characteristics.

4.17 In these terms it is evident that the proposals for architectural lighting have been carefully devised to both sustain and enhance the special interest of the listed building and the appearance of the conservation area. The lighting scheme, combing technical and aesthetic considerations, will enhance and bring the building to life during hours of darkness. The proposed lighting scheme meets the objectives of statute and national and local policy and guidance for the historic environment.

Amendments to retained façade 4.18 On balance of all technical and aesthetic considerations (set out in the architects supporting document) the strategy for careful repair and re-fixing of façade stones is concluded to the best option to sustain the architectural and historic interest of the listed building.

4.19 The works are required to ensure the future integrity of the listed building and when carried out in the manner proposed will ensure that the significance of the listed building is sustained and conserved.

Façade (stone) cleaning 4.20 Careful and appropriate cleaning of the existing Portland stone cladding (including that to be carefully removed and reinstated on more secure fixtures – above) will significantly improve the appearance of the listed building, enhancing its architectural interest.

4.21 The proposals will therefore enhance the significance of the listed building and its contribution to the character and appearance of the conservation area and the setting of adjacent and nearby designated heritage assets.

5. Conclusion

5.1 Listed building consent and planning permission are sought for Amendments to the previously consented proposals (the ‘Approved Scheme’) comprising:

c. Proposed cleaning of all existing Portland stone that has been retained, including the reinstated stone cladding of the cruciform columns.

5.2 This document acts as an addendum to the original Heritage, Townscape and Visual Impact Assessment (HTVIA) that supported applications 16/06423/FULL and 16/06463/LBC and to the subsequent addendum document which supported applications 18/03520/FULL and 18/03517/LBC.

5.3 The proposed lighting scheme will realise the opportunity of better revealing the architectural interest and role of the listed building within Grosvenor Square and the Mayfair Conservation Area. The scheme is well designed and co-ordinated and appropriate to the scale of the building and its setting, drawing attention to the building’s architectural characteristics. The proposals for architectural lighting have been carefully devised to both sustain and enhance the special interest of the listed building and the appearance of the conservation area.

5.4 The proposed amendments to retained façade are made after careful consideration of all technical and aesthetic considerations. The strategy for careful repair and re-fixing of façade stones is concluded to the best option to sustain the architectural and historic interest of the listed building. The works are required to ensure the future integrity of the listed building and when carried out in the manner proposed will ensure that the significance of the listed building is sustained and conserved.

5.5 The proposed careful cleaning of the existing Portland stone cladding (including that to be carefully removed and reinstated on more secure fixtures – above) will significantly improve the appearance of the listed building, enhancing its architectural interest.

5.6 The proposals will therefore enhance the significance of the listed building and its contribution to the character and appearance of the conservation area and the setting of adjacent and nearby designated heritage assets.

5.7 For these reasons the proposed amendments will not cause harm to the special interest and heritage significance of the listed building or its wider conservation area and townscape context whilst ensuring the building’s sustainable conservation. In these terms the proposals fully satisfy the requirements of primary legislation and national and local heritage planning policy.

Appendix 1: Statement of Significance: Former United States of America Embassy, Grosvenor Square (Grade II listed building)

Introduction

1. The following overview of the history and context for the design and development of the United States Embassy in Grosvenor Square, including understanding of the architect and his brief, is drawn from a number of sources. Extensive visual archives of Saarinen’s work are available - most notably the Korab Collection11 held by the Library of Congress; the Cranbrook architectural drawing collection12; and, Yale University Library13 collection.

The Architect: Eero Saarinen

2. Eero Saarinen was the son of the influential Finnish architect, Eliel Saarinen, born on his father's 37th birthday, August 20, 1910. The family emigrated to the United States of America in 1923, when Eero was 13. He grew up in Bloomfield Hills, Michigan, where his father was a teacher at the Cranbrook Academy of Art (where he took courses in sculpture and furniture design). He had a close relationship with fellow students Charles and Ray Eames, and became good friends with Florence Knoll.

Figure 1: Eero Saarinen 3. Saarinen first received critical recognition while still working for his father, for a chair designed with Charles Eames for the "Organic Design in Home Furnishings" competition in 1940 – receiving first prize. The "Tulip Chair", like other Saarinen chairs, was put into production by the Knoll furniture company, founded by Hans Knoll, who married Saarinen family friend Florence (Schust) Knoll. Attention also came while Saarinen was still working for his father, when he took first prize in the 1948

11 A selection of almost 800 photographs by Balthazar Korab documents 19 projects designed by Eero Saarinen. 12 The Cranbrook Architectural Drawing Collection has over 22,000 architectural drawings in its collection including campus-related architects such as Eero Saarinen, 13 Manuscripts and Archives Digital Images Database (MADID), Yale University Library

competition for the design of the Jefferson National Expansion Memorial, St. Louis (although not completed until the 1960s).

4. From September 1929, he studied sculpture at the Académie de la Grande Chaumière in Paris, France and then went on to study at the Yale School of Architecture, completing his studies in 1934. Subsequently, he toured Europe and North Africa for a year and returned for a year to his native Finland, after which he returned to Cranbrook to work for his father and teach at the academy. He became a naturalized citizen of the United States in 1940.

5. Saarinen was recruited by Donal McLaughlin, an architectural school friend from his Yale days, to join the military service in the Office of Strategic Services (OSS), where he was tasked with drawing illustrations for bomb disassembly manuals and provided designs for the Situation Room in the White House. He worked full-time for the OSS until 1944, and after his father's death in 1950, founded his own architect's office, ‘Eero Saarinen and Associates’. Eero Saarinen died of a brain tumour in 1961 at the age of 51.

Figure 2: General Motors Technical Center, Warren, Michigan 1946-56

6. One of Saarinen's earliest works to receive international acclaim is the Crow Island School in Winnetka, Illinois (1940). However, his first major work in collaboration with his father, was the General Motors Technical Center in Warren, Michigan, noted to follow the rationalist Miesian style, incorporating steel and glass but with the added accent of panels in two shades of blue [Figure 6].

7. The GM Technical Center was constructed in 1956, with Saarinen using architectural models and mock ups allowing him to share ideas and gather input from other professionals. With the success of the scheme, Saarinen was then invited by other major American corporations such as John Deere, IBM, and CBS to design their new headquarters. The building interiors usually contained dramatic sweeping staircases and furniture designed by Saarinen.

Figure 3: The TWA Flight Center or Trans World Flight Center, for Trans World Airlines at New York City's John F. Kennedy International Airport opened in 1962

8. In the 1950s he began to receive more commissions from American universities for campus designs and individual buildings, including; the Noyes dormitory at Vassar; Hill College House at the University of Pennsylvania; an ice rink, Ingalls Rink; Ezra Stiles & Morse Colleges at Yale University; the MIT Chapel and neighbouring Kresge Auditorium at MIT; and, the University of Chicago Law School building and grounds.

9. Saarinen served on the jury for the Sydney Opera House commission and was crucial in the selection of the now internationally known design by Jørn Utzon (a jury not including Saarinen had previously rejected Utzon's design in the first round but Saarinen recognised a quality in his design and ultimately assured his commission).

10. First known as "Saarinen, Swansen and Associates", headed by Eliel Saarinen and Robert Swansen from the late 1930s until Eliel's death in 1950, the practice was located in Bloomfield Hills, Michigan, until 1961 when it moved to Hamden, Connecticut. Saarinen was principal partner from 1950 until his death in the subsequent Eero Saarinen and Associates.

11. Under Eero, the firm carried out many of its most important works, including the Bell Labs Holmdel Complex in Holmdel Township, New Jersey; Jefferson National Expansion Memorial (including the Gateway Arch) in St. Louis, Missouri; the Miller House in Columbus, Indiana; the TWA Flight Center at John F. Kennedy International Airport working with Charles J. Parise [Figure 7]; and, the main terminal of Dulles International Airport near Washington, D.C.

12. One of the best-known thin-shell concrete structures in America is the Kresge Auditorium (MIT) [Figure 8] designed by Saarinen; whilst he also used thin-shell technology to create his Yale's Ingalls Rink, which has suspension cables connected to a single concrete backbone nicknamed "the whale". Undoubtedly, his most famous work is the TWA Flight Center, which represents the culmination of his previous designs and demonstrates his ‘neo-futuristic’ expressionism and the technical marvel in concrete shells.

Figure 4: Massachusetts Institute of Technology, Kresge Auditorium and Chapel, 1951-55

13. Despite attracting criticism from orthodox modernists for his perceived lack of signature style and historicism, after his untimely death in 1961, at the age of 51, Saarinen was posthumously awarded the Gold Medal of the American Institute of Architects – its highest tribute. More recent interest in ‘Mid-century Modernism’ has led to wider recognition of Saarinen’s unique skill in adapting his own modernist vision to each individual client, project and context.

UK Executive Architects and Structural Engineers

14. In London for the United States Embassy building, Saarinen was assisted by Yorke, Rosenberg and Mardell as UK executive architects. The practice was formed in 1944 by Francis Reginald Stevens Yorke, English architect and author, and one of the first native British architects to design in a modernist style14. He made numerous contacts with leading European architects while contributing to the Architects Journal in the 1930s and in 1933 was secretary and founder member of the MARS Group. Between 1935 and 1937 he worked in partnership with the Hungarian architect and former Bauhaus teacher Marcel Breuer, before forming YRM partnership where he designed many post-war buildings, including St Thomas's Hospital in London.

14 Oxford Dictionary of National Biography (Online edition). Oxford: Oxford University Press

15. The structural engineers for the London project were FJ Samuely and Partners. The firm originated in 1933, when Felix Samuely came to Britain and worked on a number of well-known and innovative structures including the De La Warr Pavilion at Bexhill; Simpsons Piccadilly; and, the Skylon for the Festival of Britain. F J Samuely and Partners was formed in 1956, and Frank Newby became senior partner in 1959 (when Felix Samuely died prematurely).

16. He was appointed in 1960 to work on the American Embassy in London after meeting Eero Saarinen in the United States15, where in 1952, he was fortunate to win a United States government scholarship to study building methods in America; an experience that influenced him greatly and made his name known to many leading local architects. He learned about structural joints from Konrad Wachsmann; worked for Charles Eames on a film about communications; made the acquaintance of Mies van der Rohe and his engineer Myron Goldsmith; and, accompanied Eero Saarinen to the first fixing of a neoprene rubber seal for the pioneer glass cladding of the General Motors research centre16.

17. Newby went on in 1965 to design a new Aviary for Regent's Park Zoo, with Cedric Price and Lord Snowdon and to work with the Chicago based firm of Skidmore, Owings and Merrill to design a new factory for Boots in Nottingham, completed in 1968. The most celebrated of his buildings is the Engineering Building at the University of Leicester, designed with James Stirling and James Gowan.

18. Anthony Hunt also worked on the American Embassy project and was inspired to seek employment with FJ Samuely & Partners after being impressed by the Festival of Britain's Skylon. Following a spell working for Terence Conran and for Hancock Associates, Hunt went on to found Anthony Hunt Associates in 1962 and work with a new generation of British architects, including Norman Foster, Richard Rogers, Michael Hopkins and Nicholas Grimshaw. He played a significant role in developing the lightweight, prefabricated style of British architecture known as ‘High Tech’.

The United States Embassy Building Programme 1954-1960

19. The expanded United States of America embassy building programme was a response to the challenges facing the nation in the immediate post war period, following the warning by Winston Churchill in 1946 of an “Iron Curtain” being drawn across Europe, and the ensuing Cold War.

20. The programme reached its peak in terms of scope and popularity in the confident years that followed World War II, before the turmoil of the 1960s and 1970s, marked by political doubts and rising concern for security. The programme was part of America’s wider effort to define its world role and new embassies were hailed as evidence of goodwill and commitment with their noble architecture introduced in the late 1940s coming to symbolise the openness of public diplomacy.

15 ‘While working in Saarinen’s office [Newby] had impressed the latter with his suggestions for the design of the Milwaukee Memorial Building. Saarinen then turned to the Samuely partnership for the engineering of his award-winning American embassy in London’. David Yeomans, ‘Frank Newby (1926-2001)’.Oxford Dictionary of National Biography. 16 Frank Newby, Obituary, The Guardian, 29th May 2001

21. Architectural modernism became linked with the idea of freedom after the war and American architects emerged as leading proponents of the Modern Movement. The Office of Foreign Building Operations (FBO) began to showcase modern architecture in its first major post-war projects.

22. Its Architectural Advisory Panel (AAP) (predecessor of the Architectural Advisory Committee (AAC)) met thirteen times in 1954, and reviewed plans for twelve new projects including eight embassy office buildings, recommending architects for the new jobs. It met a further ten times in 1955, to review eight projects and in 1956, met twelve times – with members serving on the seven-man jury that judged the London competition in February.

23. The embassies reviewed in 1956 included Accra (Harry Weese); Saigon (Curtis and Davis); London (competition winner Eero Saarinen); Manila (Alfred L Aydelott); Ciudad Trujillo (Rogers, Taliaferro & Lamb); Athens (Walter Gropius, TAC); Rabat (Ketchum, Gina & Sharp); Lima (Keyes & Lethbridge); Helsinki (Harwell Harris); and, The Hague (Marcel Breuer).

Embassy Building Requirements

24. The embassy building model was relatively simple. Architects were required to provide separation between public and private (or non-public) space within each office building. At many sites the lobby area was open to the public and public orientated functions adjoined the lobby. Offices requiring limited access were then stacked above, accessible via lifts or stairs situated beyond a reception desk or checkpoint.

25. The need to separate functions produced plans in which United States Immigration Services (USIS) offices, libraries and auditoriums for example, had separate entrances often set to the side of the main embassy. At London and Oslo, Eero Saarinen provided three entrances – an entrance for consular offices on one side, one for USIS on the other, and a main entrance for other embassy business in the centre.

26. The Great Seal and the American flag were the two national symbols used by architects to identify embassy buildings. They also variously interpreted the American eagle, which is part of the seal, to add emphasis and a visual accent to highly symbolic buildings. The great eagle mounted on the building in London was, however, unique. Earlier schemes, such as Brussels, had incorporated the eagle motif into embassy identification plaques or signs, but Saarinen was the first to use the eagle as a separate sculptural element. No one, other than Saarinen, ever tried anything as provocative or tried to explore the use of American political symbols to the same extent. The London eagle caused much consternation but remains an eye-catching focal point on the façade. John Johansen later mounted a smaller, even more stylised golden eagle, above the entrance to the Dublin embassy.

27. Every embassy also featured a prominently placed flagpole and an American flag flying above. Where poles were mounted on embassy roofs such as London, Oslo and Quito, the flag became a key locator and signal of the American presence. Before American embassies became targets of attack at the time of the Vietnam War, there was little concern for perimeter security and no need to downplay the presence of the embassy.

Saarinen’s Oslo Embassy

28. Saarinen designed embassies in Oslo and London and served on the Architectural Advisory Panel (AAP) providing design advice to the State Department.

29. He won the commission to design the United States embassy in Oslo in June 1955. Unlike many of the other young architects retained by the FBO, Saarinen had already collaborated on many large-scale projects, including college dormitories and office buildings. He has just completed the Kresge Auditorium and chapel at the Massachusetts Institute of Technology (MIT) when he was approached by FBO to design the Oslo building.

Figure 5: Saarinen’s American Embassy for Olso (Manuscripts & Archives, Yale University Library)

30. FBO director Leland King first hired the Finnish-born Saarinen to design a new chancery for Helsinki, but that project was suspended when King was dismissed late in 1953. As a rising star in the profession, Saarinen was a logical choice for another FBO commission and with Finland no longer available, the AAC offered Norway as the next best alternative. The site was prominently located on a major street across from the gardens of the royal palace and triangular in shape to challenge any architect.

31. Saarinen made his first presentation of preliminary drawings and floor plans to the AAC on 10th November with his proposal featuring load-bearing wall construction made of re-fabricated modular stone panels – notably no ‘stilts’ or ‘glass walls’ were present as these were not favoured by the AAC or its predecessor.

32. The four storey building was of triangular plan to accord with the site, abutting the pavement with off-street parking on all sides, with central courtyard sky-lit from above.

Figure 6: United States of America Embassy, Oslo - central atrium 1959

Figure 7: United States of America Embassy, Oslo, as built

33. The projecting marquee or canopy over the main entrance was particularly admired by members of the AAC. Two additional entrances at either corner of the front façade led to consular offices on one side and the USIS offices and library on the other. The flagpole mounted on the entrance canopy roof was suggested by the AAC and added to the central focus of the principal elevation.

34. Saarinen presented the project once in November, and again in March 1956, and with the great respect for his talent among members of the AAC general agreement was reached that the design met FBO requirements after just the two meetings.

35. As originally presented, the colour scheme was black and gold but in the end the black remained but the gold was omitted. The architect had intended to use polished granite pier facings with windows and spandrels conspicuously framed in lustrous bronze, but he agreed, as he later would at London, that less costly gold-finished anodized aluminium would work as well as bronze. Eventually, he had to settle for even less expensive teak, painted white and as a result the building never had the ‘dazzle’ that Saarinen intended. The new embassy had an air of permanence, seriousness, and modernity, standing by itself as city block where it took on a certain prominence in a cityscape that boasted few modern buildings.

London and Grosvenor Square

36. London was considered the most important project on the FBO agenda in 1955 and sufficient to warrant a trip by Ralph Walker to assess the embassy site. Walker, a graduate of MIT, had served as president of the American Institute of Architects (AIA) from 1949 to 1961; was partner in the New York firm of Voorhees, Walker, Foley & Smith; and, a Fellow of the AIA.

37. He reported that the problem at London was preservation of the scale and quality of a historic district. Dismayed by the “new so-called modern abortions” he saw in London’s Berkeley Square, he called upon his AAC colleagues to recognise the patterns and proportion that characterised C18th and C19th squares and urged selection of designs that aimed for harmony above all else.

38. Walker thought that the key to successful urban design in European cities lay not in conspicuous newness, but rather in the opposite direction. “Steel and glass”, he wrote, “seem all too inappropriate, all too temporary and, moreover, all too impersonal. There is need for a new monumentality, quirt and restrained, without any sense of the stunt.”

39. Notably, the United States had been associated with London’s Mayfair and, specifically, Grosvenor Square since John Adams arrived in London in 1785, as the first American minister to Great Britain. Adams rented a red-brick house (no.9) that still stands in the northeast corner of the square (grade II listed c.1725 by William Barlow and one of only four houses surviving the mid C20th rebuilding of the square17). Although the legation did not remain in the square it stayed in the area. In 1913, in the days when the American ambassador still had to find and pay for his own lodging, Walter Hines Page again rented a house on the Square, this time at no.6.

17 Survey of London; Vol. XL

40. The British government completed construction of its new embassy/residence in Washington in 1931, and the Lutyens designed building was hailed at the time as the ultimate in embassy architecture. The FBO stepped up its effort to secure a comparable property for the United States in London - the only major foreign capital that lacked a government-owned embassy at the time. Property was looked at in Trafalgar Square but no deal was struck and instead a former J P Morgan residence, donated to the State Department in 1921, was refurbished and a lease secured for office space in the newly constructed seven storey office building on the east side of Grosvenor Square (No.1).

41. Later, when General Eisenhower arrived in London during World War II, he also set up his headquarters on Grosvenor Square, opposite the embassy offices on the west side of the square. Admiral Stark, Commander of U.S. Naval Forces in Europe, also directed the naval part of the great build up in England and U.S. naval operations and training activities on the European side of the Atlantic from his London headquarters in Grosvenor Square. In 1947, officials erected a statue of Franklin Roosevelt on the north side of the gardens (by W Reid Dick, grade II listed), which were also re-planned in his memory with the area known locally as ‘Little America’.

42. The building leased by the United States in 1937, was one of the first projects completed according the Duke of Westminster’s ‘neo-Georgian’ plan, which envisioned Grosvenor Square bordered by similar looking buildings, offices, hotels and luxury apartments. This plan remained in effect when the United States began to consider building a new office building along the west side of the square after the war and was in Saarinen’s mind in designing his competition scheme. In his own words Saarinen’s design “anticipate(d) the changes that will occur there when the three sides of the square will be in nine-storey pseudo-Georgian buildings, The square is in transition and our building is built for the future. The mass and general cornice height, the silhouette, conform to those of future buildings”.

43. Prevented by statute from owning land, the United States government could still lease land and own buildings built upon it. In a position to exchange foreign war debts for valuable real estate, the State Department purchased nos. 1, 3 and 20 Grosvenor Square in 1947, at the same time signing a 99 year lease with the Duke’s estate. A year later, in order to provide space for the burgeoning USIS operation, the department purchased no.5, which didn’t adequately meet needs due to tenants still occupying apartments in the building. The long range plan, according to former FBO director, Leland King, was to sell the newly acquired properties and use the proceeds to help finance the construction of a consolidated office building on a site nearby.

Figure 8: Buildings on the west side of Grosvenor Square before demolition (Survey of London)

44. In 1950, the FBO entered discussions with Grosvenor Estate and acquired the west side of Grosvenor Square as an embassy site. Prior to construction, the existing buildings partly damaged by wartime bombing, had to be demolished. Despite later criticism by Congress, the acquisition of the site without direct cost to American citizens due to a purchase derived from war credits appears to have been far-sighted.

Figure 9: Grosvenor Square West side in 1957 just before demolition (Survey of London)

45. The London project was deemed important enough to justify the expense and time of a competition, the first in FBO history. Robert W McLaughlin Jr. (head of Princeton’s architectural programme) was selected as professional advisor and in turn selected the entrants, agreed upon the format and the programme and announced the competition in the autumn of 1955. The Princeton programme was relatively free of the modernist dogma taught at other design schools and McLaughlin, a member of the executive committee of the Architectural League of New York and a trustee of the Beaux-Arts Institute of Design, had a passion for archaeological studies.

46. Surprisingly, the pressure to build a ‘traditional’ embassy building in London came more from the American than the British side. The US Ambassador Winthrop, W Aldrich, presented the strongest case for the importance of tradition and even sought to persuade the AAC that the London embassy should be built “in the nature of the late eighteenth century architecture as designed by Nash”. He was emphatic that the Grosvenor Estate would never condone a contemporary building and this led to acrimonious discussions with members of the AAC who pointed out that other such buildings had been allowed in London.

47. In contrast, the Royal Fine Arts Commission “hoped that American architects would not be influenced by the architecture of Lutyens”, instead looking forward to a design that “would not be stodgy English but purely American...expressive of the best that is being designed in America today”. However, they did share the Ambassador’s objections to glass and steel and agreed that a skyscraper would be inappropriate but nevertheless did not want undue restrictions imposed on the architects taking part in the competition.

Competition

48. The strongest indication that the AAC favoured a modern building is seen in the selection of architects – only eight firms were invited to participate in the competition: Anderson, Beckwith & Haible; Ernest J Kump; Eero Saarinen & Associates; Josep Luis Sert with Huson Jackson and Joseph Zalewski; Edward Durell Stone & Associates; Hugh Stubbins Associates; Wurster, Bernardi & Emmons; and, Yamasaki, Leinweber & Associates – all committed modernists. Each was paid $4,000 for a design and to cover expenses as each participant was required to travel to London to inspect the site in person.

49. The ten page competition programme emphasised context but advised participants not to try to copy other buildings directly but to pay careful attention to the historic surroundings. The programme called for an office building with a maximum of 150,000 square feet of floorspace divided into three areas, each with a separate entrance; the central administrative area, including the ambassador’s offices (121,500 sq.ft); the consular and visa area (15,000 sq.ft); and, offices for the USIS (13,500 sq.ft).

50. Specific space requirements were outlined for the lobby; the ambassador’s office; his staff; the deputy chief of mission; and, the political counsellor. The ambassador’s office had to be accessible through public hallways and also through private corridors connected to the offices of other key officials, it should not be on the ground or first floors and that there should be at least two floors above it. The basement was to contain areas for storage, service and a cafeteria, and the sub-basement was to provide parking for 25 cars. The building was not to be air-conditioned, materials were to be procured if possible in England, and the overall height was not to exceed 100 feet. The programme stated:

“The building will occupy and visually establish one side of the Square” and “Its visual relationship to the other three sides as well as to the surrounding area of London is of the utmost importance.”

51. Notably, the scheme was also required to be capable of doubling in size if future needs necessitated, although Saarinen as with most of the entrants, generally ignored this requirement. It is also noted that at the time of the various participants’ site visits during one of the worst winters on record, that Grosvenor Square was seen to be in a poor state of repair, with the railings removed and the gardens neglected. Whilst all the invited architects visited London, Saarinen spent his three-week honeymoon here, covering the walls and mirrors of his hotel suite with sketches for the competition. He produced scores of alternative designs before arriving at a unified, symmetrical composition generally featuring a tripartite elevation composed of base, a centre and a top.

52. The competition review was set for 14th February 1956, in Washington, and the entries varied widely18. Minoru Yamasaki’s scheme comprised two connected parallel buildings wrapped in a ‘lacy stone-clad screen’ with arched openings reminiscent of an English Perpendicular Gothic façade. William Wurster sought to capture the contrast he saw in London’s architecture between black and white – using white Portland stone and black brick as facing on his seven storey building which extended the full width of the square. The Anderson, Beckworth & Haible scheme also extended the full width of the square – the design noted to be ‘so tactful as to lack any semblance of personality’. Ernest Kump’s design similarly lacked any hint of the building’s special purpose, featuring an enormous five storey portico together with glass-clad interior courtyards.

53. Stubbins proposal featured a building raised on stilts with a glass walled lobby and open courtyard accessible to pedestrians via an arcade that ran through the main building. Sert’s design was less planar than others, with boxy volumes defining spaces with a window pattern, like Saarinen, that alternated fixed glass with narrow movable glass panels.

54. Stone’s design, aside from Saarinen, was the only one to try and grasp the importance of the embassy as a symbol and his design later became one his trademark designs, with a seven storey block with façade of floor to ceiling windows set back behind thin columns, topped by a roof loggia and flat, overhanging the roof. Like Saarinen his scheme was composed symmetrically and did not extend to the edges of the square and surrounded the building with parking areas and trees. Notably, the scheme included two sky-lit courtyards landscaped with fountains, trees and hanging gardens – an ‘atrium plan’, to be later popularised by the architect John Portman.

18 The Architecture of Diplomacy, Building America’s Embassies, Jane C Loeffler (1998)

Saarinen’s London Embassy

55. Hugh Pearman notes19 that although the context for the new embassy building was the Georgian and pseudo-Georgian character of Grosvenor Square, Saarinen’s historic point of reference was quite different in that he kept a large picture of the Renaissance Doge’s Palace, Venice, pinned above his drawing board.

56. Saarinen’s competition scheme comprised a symmetrical building featuring a large replica of the Great Seal mounted prominently over the entrance, just below an elaborate cornice. The 5 storey building was classically divided into base, middle and top, and to give emphasis, drew the building in from the edges of the block. Whilst avoiding a clear distinction between window and wall, the window openings were scaled to the windows of nearby buildings, alternating opening windows with fixed glass panels, mounted like pictures in flat frames of Portland stone.

57. The jury found itself choosing between Stone and Saarinen sensing that whilst Grosvenor Estate had waived its right to insist on a neo-Georgian design (which the competition was not looking for), that nevertheless, a compromise was likely to be necessary.

Figure 10: The Doge’s Palace, Venice – Renaissance inspiration for Saarinen?

19 The Wall Street Journal, 8th October 2008

Figure 11: United States Embassy, London, 1955-60 – examples of Saarinen’s early elevation studies

Figure 12: United States Embassy, London, 1955-60 – example of Saarinen’s early north elevation

Figure 13: Saarinen’s official competition entry ‘English watercolour’ perspective

58. The scheme Saarinen proposed but not built, used Portland stone as the principal building material with bronze for the detailing – the exterior elevations referred to as “an English pre-cast structural system”. Elegant and expensive materials also added to the formality and distinction of the design with sand-moulded, black oxidised bronze for the cornice and natural bronze for the Great Seal and a protective grill at ground level. Saarinen imagined that the building would blacken with soot like many other London landmarks and that the bronze would add brightness.

59. The competition was covered in British newspapers and the major architectural journals from both countries announced the results and ran pictures of the designs. The Times cited the winning project as a “welcome acquisition” to the area and noted how well Saarinen had harmonised his design with its context, commending the choice of a “strictly symmetrical” building that retained “the traditional formality of the London Square”. However, other British publications reacted differently with the Architects Journal praising the building for not fitting in where “it will provide a welcome example for future development in an area unduly wedded to neo-Georgian commonplaceness”. Notably, American journals generally reported the competition results with little enthusiasm.

Figure 14: Saarinen with architectural model of competition scheme

Figs 15 & 16: Architectural models – above, the competition scheme; below, the revised scheme

60. It also appears that the result was marked by serious disagreement within the jury itself with Walker commenting that nearly all the designs were completely lacking in taste, writing rather dramatically in September 1956 to his AAC colleagues that “I thought the nadir in American architectural design had been reached in the London competition”.

Saarinen’s Revised Scheme

61. After the competition was over, the brief for the building was changed to accommodate additional public spaces, in turn necessitating the addition of another floor below the main level. It is noted that Saarinen was pleased by this change20 as he wrote “with time the competition design started to look like Toulouse-Lautrec – with too short legs”. His answer was to raise the entrance floor to be was set above a lower ground floor.

62. It was at this point that Saarinen devised a solution for the exterior where the load bearing precast frames bore onto a horizontal zigzagging ‘diagrid’, transferring the load to cruciform recessed columns below. As he described it21 “the façade one sees is the bones of the building. The coupled columns [precast frames] on the upper floors carry all the weight down to the outer edge of the diagrid; this diagrid transfers the load horizontally to the first floor columns”.

Figure 17: Model of typical bay – Saarinen’s studio

63. He presented this new scheme to the AAC on 15th May 1956, where it was agreed that the new height did not adversely affect the building’s relationship with its neighbours. The new ‘diagrid’ system of criss-crossed supporting beams evidenced both inside and

20 Eero Saarinen Shaping the Future, (2006) 21 Ibid

out was praised, permitting the main façade to overhang the column line. Saarinen referred to the metal fasteners trimming the windows and other related details as providing the opportunity to “add sparkle to the façade”.

Figure 18: Sketch of revised scheme with perimeter screen wall at street level22

Figure 19: Details of diagrid floor construction and facade

64. However, in order to reduce costs, he was forced to abandon his preference for bronze, substituting gold-coloured anodised aluminium in its place. The Great Seal was

22 Historic England Historian’s File “Archive sketch”

also replaced in the revised proposals by the eagle – although there was no mention of this motif at the May presentation and the eagle did not appear until later.

65. The AAC approved and commended the scheme as a “real improvement over the competition design” and Saarinen flew to London to make arrangements for construction. A planning application was submitted on 26th April 1956, with permission granted by the London County Council on 4th October 1956. An informative advised that means of access required further attention and that the Royal Fine Art Commission had advised that “a less emphatic treatment of the proposed wall surrounding the building would be desirable”23. It appears that the sloping ‘glacis’ was then introduced in place of the perimeter screen wall in 1957 in working drawings dating to April of that year.

Figure 20: Construction of the entrance floor with diagrid and cruciform columns

66. Once the embassy was under construction, in late 1957, Saarinen also proposed the addition of the 35 foot-wide eagle, created by the American sculptor, Theodore Roszak24 out of gilded aluminium. The sculptor’s inspiration had been a pre- Independence carved wooden eagle seen in a New England museum and from the outset the sculpture raised questions. Saarinen already a member of the AAP made a presentation to the panel where it was unanimously supported by the panel members.

23 London County Council Permission for Development, 4th October 1956 (WCC) 24 “In 1960 commissioned by Eero Saarinen to fabricate a thirty-seven-foot, two thousand pound aluminum eagle for the front facade of the American Embassy in Grosvenor Square, London. Executes another eagle for the Federal Court House, New York”. Polish American sculptor and painter (1907-1981). Chronology by Douglas Dreishpoon

Figure 21: Sculptor Theodore Roszak with his eagle sculpture

Critical Reaction

67. However, upon opening of the embassy in 1960, the eagle drew much of the negative attention that greeted the building – being seen as too loud, blatant, oppressive and fierce. Some critics also worried that the eagle was iconographically incorrect as it looked to the left instead of the right, as was the custom, and it was missing the arrows clutched in the left talon and the olive branch in the right – traditional symbols of war and peace. In response, Saarinen published a statement where he defended the plan, the design and the eagle, which he said, “is used not in the form of the great seal, but freely and symbolically as it so often has been used in the past”25.

68. British comments compared the building to “a cigarette factory” and remarked upon its “Hollywood-Broadway influence”, whilst comments from American politicians were similarly negative. Scathing remarks from British architects and critics were also published in America. Critics, including Peter Smithson, called for something far more daring and questioned the very idea of wanting to fit in.

69. Fello Atkinson, writing in the Architectural Review, seems to have appreciated what Saarinen was intending to achieve, praising the metal trim for its richness and for the way it reflected light. The interior, he observed, was probably the most successful part of the building, although it figured relatively little in the competition. He compared the interior to those of Charles Rennie Mackintosh and Josef Hoffmann, commending its

25 USA Embassy, Architect and Building News, 7 December 1960

quiet elegance, illustrating his article with photographs of the hallways, stairways, handrails, ceiling modules and doors and the furniture, some custom designed from Knoll and other pieces by Charles Eames Atkinson. He explained how the diagonal structure and the right angle-plan sought to move beyond the Miesian grid to a “newer plastic phase”.

Figure 22: The United States of America London Embassy upon completion with Eagle sculpture and sloping glacis

70. The façade proved particularly controversial – consisting of a stone screen or grille made up of precast concrete window frames arranged in a not quite linked chequerboard rhythm. Felix J Samuely had pioneered the development of external precast concrete load-bearing construction in the 1950s and Saarinen was a keen advocate of the latest structural techniques and technologies. However, the façade was seen by many as being too energetic and too artificially stylised for its Georgian setting and ambassadorial function. Saarinen was clear that his building anticipated the changes that would occur when the three-sides of the square are redeveloped with nine-storey neo-Georgian blocks, as then envisaged by the Grosvenor Estate masterplan.

71. The final revised design, with raised entrance floor, incorporated a gently sloped base, or glacis, which inadvertently provided a subtle defensive device to separate the building from the pavement (prior to the installation of the security measures). However, the building did not take on the rich black lustre expected from pollution due to new controls and regular cleaning.

72. In 1980, the Survey of London26 recognised that the building “raised and protected on a fence-topped glacis and set back from the notional boundaries of the west side of the Square” represents “in its islanded integrity a startling contrast to the accommodation taken [by the American Embassy] in 1938” and that “for all its unaggressive form it has tended to give the Square a westward rather than a northward orientation”.

73. Hugh Pearman27 has noted more recently, the effect of the passage of time on critical review demonstrated by the original and subsequently revised entries in the Buildings of England series for the building. Writing in the early 1960s, Sir Nikolaus Pevsner said28 of Saarinen’s building:

“Grosvenor Square...is dominated by the United States Embassy by Eero Saarinen, an impressive but decidedly embarrassing building. The impressive thing is the ground floor, very tall, and the underside of the first floor, which is a grid of diagonally arranged concrete beams. Their ends are exposed outside, and they also appear inside. The inside finishes are extremely impressive too.

What remains, however, embarrassing is that above the ground floor the façade of the building turns conventional in an effort of its architect to be in tune with the London tradition. Considering the interesting and impressive work that he did in Detroit and in other places this is disappointing, especially as the Georgian proportions of the windows are then given an unexpected twist by the introduction of a chequerboard rhythm of the surround and by making them of gilded aluminium.

The rhythm of this gilt-edged fenestration seems a very superficial way of achieving interest, just as the symmetry and the Georgian allusions are a superficial way of achieving monumentality. The large eagle standing 8 to 9 feet up against the sky at the top in the middle and having a 35-foot wing-span (by Theodore Roszak) further emphasises this forced monumentality.”

74. Whereas, in writing the latest revised edition of the Buildings of England volume for Westminster29, Simon Bradly remarks:

“Chief bone of contention was the façade…Nowadays fewer people will be troubled by such pattern-making, which was then common enough on both sides of the Atlantic, though rarely made so explicitly screen-like.”

Protest and Commemoration

75. Protesters attacked American embassies as the United States deepened its involvement in Vietnam in the mid-1960s. Throughout the 1970s, terrorists targeted American embassies and the State Department moved to increase Marine guard detachments, building checkpoints and installing security lobbies. The FBO retrofitted

26 Survey of London: Volume 40, the Grosvenor Estate in Mayfair, Part 2 (The Buildings) 27 Save our Saarinen! The American Embassy in London under threat, Hugh Pearman, Wall Street Journal, October 2008 28 London 1: The Cities of London and Westminster, Nikolaus Pevsner, (revised) 1962 29 London 6: Westminster, Simon Bradly and Nikolaus Pevsner, 2003

embassies, notably London, Oslo, Dublin and The Hague with surveillance equipment and vehicle barriers with USIS entrances locked and barred from use.

Figure 23: Grosvenor Square 1968 – anti Vietnam war protests

76. More recently, the Embassy was the focus for those wishing to pay their respects after the 11th September attacks in the United States in 2001. Statues have also been erected of General Eisenhower and President Ronald Reagan further reinforcing the United States association with the Square.

Change and Adaptation

77. The building has been altered and regularly adapted to meet changing use and security requirements since opening. More recent development has included the installation of CCTV cameras (1992); external alterations at penthouse level (1996); disabled access ramps (1996); installation of anti-ram barriers (2001); and, security screening pavilions, associated security fencing, bollards, re-paving works and security barrier and gates (2003-2005).

78. In 1988, a statue of General Eisenhower was erected on the north-east corner of the Embassy forecourt (subsequently set within raised planters incorporating security measures) and a statue of Ronald Reagan was erected on an existing raised planter on the south west corner, together with bronze plaques and piece of the Berlin wall, in 2009.

Contemporary photographs30

Figure 24: Front, Grosvenor Square elevation c.1960

Figure 25: The Library c.1960 (converted to a waiting room for visa applicants by the 1970s)

30 Korab Collection

Figure 26: Front elevation from Grosvenor Square c.1960

Figure 27: The Auditorium c.1960

Figure 28: From the Library looking out to the Square c.1960

Figure 29: The northeast corner – Grosvenor Square c.1960

Figure 30: Front elevation and the Eagle c.1960

Figure 31: Main entrance lobby c.1960

Figure 32: Rear elevation seen from Culross Street c.1960

Figure 33: Office interior c.1960

Figure 34: Central entrance lobby c.1960 (before removal of fountain)

Heritage Significance

79. For national planning policy purposes, heritage significance is defined31 “as the value of a heritage asset to this and future generations because of its heritage interest. That interest may be archaeological, architectural, artistic or historic. Significance derives not only from a heritage asset’s physical presence, but also from its setting”.

80. The grade II listed United States of America Embassy is a designated heritage asset32 and significance as a listed building derives from special architectural or historic interest33.

81. The list entry description, whilst prepared before the provisions of the Enterprise and Regulatory Reform Act 2013, is nevertheless clear regarding the reasons for listing of the building and precise regarding the nature and extent of special interest. A subsequent pre-application visit to the building by Historic England’s listing team34 has not highlighted any other substantive areas of perceived interest within the building to those noted at the time of listing.

82. Notably, at the time of listing English Heritage stated35:

Context: Embassy Building Typology

83. Until the C20th, London embassies occupied former town houses and, indeed, many still do so. Purpose-built premises emerged with the grand Dominion headquarters (or ‘empire houses’), such as Australia House (1912-18, A Marshall Mackenzie, grade II listed) and South Africa House (1931-33, Sir Herbert Baker, grade II* listed), and are functional pre-cursors.

84. In post-war London, with America leading the way, embassies became in effect specialised office buildings with a wider range of functions – besides publicly accessible spaces they might also have reception rooms, consular sections, military, security and other restricted access offices, the ambassador’s office and other spaces such as café, meeting room and library etc. The United States Embassy was Britain’s first modern embassy, followed by New Zealand House (1959-63), designed by Sir Robert Matthew,

31 NPPF Annex 2 Glossary 32 Ibid 33 Section 1 Planning (Listed Buildings and Conservation Areas) Act 1990 34 April 2015 35 English Heritage press release 22nd October 2009

and listed grade II in 1995. This was followed by the Czechoslovakian Embassy (1968-9), designed by the Prague architects J Sramek, J Bocan and K Stepanski, with Robert Matthew, Johnson-Marshall & Partners. Whilst one of the most admired and contextual post-war embassy buildings is Arne Jacobsen’s Danish Embassy in Sloan Street (1969, 1975-77).

Background to Listing

85. The listing of the building was controversial, attracting objection from a number of sources, and support from others - echoing the critical reception of the building when first constructed. As such the building’s claims to special interest were subject to much scrutiny and consideration; key aspects of which were summarised in English Heritage’s Listing Adviser’s report36 as:

• The building’s three-dimensional quality is emphasised by being set back on three of its major sides;

• The façade as a modern reinterpretation of a Greek temple raised on a podium with peristyle base and entablature-like top storey;

• Facades taking the form of a ‘monumental grille in an off-set chequerboard pattern’ with fenestration alternating paired narrow lights with fixed glass panels;

• Upper floors carried on a ‘giant concrete diagrid’ - one of the building’s principal features, expressed externally and internally throughout the ground floor, transferring load to cruciform columns beneath with exposed ends enabling the façade to overhang the column-line;

• Diagrid echoed in other details – the gilded pressed-metal parapet, cog-wheel motifs and exposed beam ends;

• Internal plan reflected the open, multi-functional United States approach to Embassy design comprising entrance lobby with large halls to left and right housing the visa section and library; large central main lobby is most notable and clad in white Greek Pentelicon marble (leading through to rear offices) with separate entrances to the Consular and Information Sections on the north and south sides; interest of other lobbies and public rooms confined to the exposed diagrid ceiling, cruciform columns and staircases with gilded cruciform balusters;

• The only UK design by Eero Saarinen and only one of three buildings designed by him outside of the United States;

• Artistic interest - American Eagle in gilded aluminium by the noted Polish- American sculptor Theodore Roszac.

36 Adviser’s Report, English Heritage (Listing) 19th December 2008

• Strong historic interest for associations with Grosvenor Square, American Armed Forces in WWII; Britain’s first modern embassy, apotheosis of post-war embassy building programme; target of 1968 anti-Vietnam war

86. During consideration of the building for listing, it was acknowledged that some elements of the building are better than others and that, as a whole, it was not among Saarinen’s leading works.

Building Form

87. Saarinen’s winning design was published in the United Kingdom in March 1956, but by June had been revised as previously described. Work began in August 1957 and the building was opened on 24th September 1960.

88. The building is of a symmetrical ‘U-plan’, comprising a raised ground floor with a central main entrance and lobby with large halls to the left (visa section) and right (library) and a large central main lobby with rooms either side, leading through to a rear single storey of offices. It has separate entrances to the Consular and former Information Sections on the north and south flank sides, each with lobby and stair to either side. The basement has a café and auditorium, both altered, whilst the upper floors provide cellular offices, which have been refurbished and re-organised over time.

89. Externally, the principal façade faces the square with shorter flank facades to the north and south, with the whole set back from the street line by the stone-faced glacis, to seek to emphasise the building’s three-dimensional qualities – appearing as a ‘object’ on the west side of the square. The principal façade is of 22 bays, arranged in tripartite form, with a central 5-bay entrance with tall recessed ground floor with 4 floors and set-back attic storey above (reinterpretation of the Greek temple – raised on a podium with peristyle base and entablature-like top storey). The north and south elevations are composed of 13 bays, each with a 3-bay entrance.

90. The facades feature tall ground floor windows, with gilded mullions and transom lights under the concrete load-bearing panels faced in Portland stone, arranged to form an off-set chequerboard pattern – the fenestration alternating paired narrow opening lights with fixed glass panels with gilded aluminium windows. The rear and inner return facades are of pre-cast concrete panels.

91. The office floors are carried on a giant concrete diagrid floor composed of intersecting diagonal concrete beams, which transfer the load to cruciform profile columns beneath. The exposed ends of the diagrid allow the façade above to overhang the ground floor column line. The use of a diagrid, invented in the 1920s, as a constructional form in the 1950s is seen as unusually sophisticated for the time – illustrating the technical prowess of the United States. Although not a feature of Saarinen’s competition-winning design, the diagrid is one of the building’s principal features, expressed both externally and internally, and echoed in other details such as the gilded pressed-metal parapet, cog-wheel window motifs and exposed beam ends. Other details include a gilded cruciform profile balustrade around the building with matching lamp standards flanking the main entrance and the 35ft aluminium eagle.

92. The architectural interest diminishes with the rear and return elevations, which continue the façade treatment of the front and flanks but are clad in concrete in place of the Portland stone.

93. Internally, special interest is confined to the ground floor public spaces, comprising the main entrance and central lobbies, passport office and former library, which have gilded cruciform columns, and the former information service and consular lobbies and stairs. All these areas have exposed diagrid ceilings.

94. The most notable area is the central lobby, which is clad in white Greek Pentelicon marble. Floors are travertine and some are replaced and the stairs to the north and south lobbies have gilded cruciform balusters.

95. Otherwise, the offices were always of little distinction and have been much altered and the ambassadorial rooms have all been refurbished in a traditional style.

96. These points combine to provide the principal reasons for listing in light of legislation (s.1 of the Planning (Listed Buildings and Conservation Areas) Act 1990 Act) and national policy (Department for Culture Media and Sport (DCMS) Principles of Selection for Listing Buildings 2010). These are articulated and summarised in the extensive list entry description.

Bibliography and Sources

Archives AJ Buildings Library (Report July 2015) Historians File WM1052, Historic England The United States Embassy, unpublished report English Heritage 1998

Books Eero Saarinen by Allen Temko (1962) Eero Saarinen on his Work – A Selection of Buildings Dating from 1947 to 1964 with Statements by the Architect, Edited by Aline B Saarinen (1968) Eero Saarinen by Robert Spade (1971) The Work of Eero Saarinen: A Selected Bibliography, Prof. Lamia Doumato, University of Colarado (1980) Survey of London: Volume 40, The Grosvenor Estate in Mayfair Part 2 (The Buildings), London County Council (1980) The Architecture of Diplomacy – Building America’s Embassies, Jane C Loeffler (1998) Eero Saarinen – An Architecture of Multiplicity, Antonio Roman (2002) Eero Saarinen, Shaping the Future, Edited by Eeva-Liisa Pelkonen and Donald Albrecht (2006) Eero Saarinen 1910-1961 A Structural Expressionist (2006)

Journals and press Architectural Design, July 1960, pp270-275 Office Block or Embassy? - The Architect and Building News, 7th December 1960 Controversial Building in London, Architectural Forum, March 1961, p81 Save our Saarinen! The American Embassy in London under Threat, Hugh Pearman, The Wall Street Journal, 8th October 2008 English Heritage press release 22nd October 2009: United States of America Embassy, Grosvenor Square

Appendix 2: Policy, Guidance and Advice: Lighting Historic Buildings (extracts)

Westminster City Council

Westminster City Plan (adopted 2016)

POLICY S25 HERITAGE

Recognising Westminster’s wider historic environment, its extensive heritage assets will be conserved, including its listed buildings, conservation areas, Westminster’s World Heritage Site, its historic parks including five Royal Parks, squares, gardens and other open spaces, their settings, and its archaeological heritage. Historic and other important buildings should be upgraded sensitively, to improve their environmental performance and make them easily accessible.

UDP (Saved) 2007

DES 7: TOWNSCAPE MANAGEMENT

Aim - To ensure the highest standards of design in all townscape details.

(B) Street furniture and floodlighting

1) Where the placement of street furniture requires planning permission, it shall be of a suitable standard of design, accord with the patterns of items already in use and generally be sited so as to be visually unobtrusive, having regard to the character and quality of the existing townscape.

2) Where the installation of floodlighting fittings and associated cabling and equipment requires planning permission, it shall be done in a visually discreet manner, having regard to the character of buildings and land on or within which it is to be located.

3) Where such installations are needed for the purposes of development for which permission is sought, they shall be designed to prevent or minimise light pollution or trespass and may be restricted as to maximum hours of operation or levels of illumination, especially in residential areas.

Floodlighting

10.81 The City Council recognises that floodlighting buildings, if carried out sensitively, can greatly enhance their appearance at night, and contribute to the attractiveness and vitality of Westminster as a centre of tourism.

10.82 Where the principle is acceptable, floodlights should be chosen and located to minimise their visual impact. Small lights should be used. Lights and cables should be coloured to match the adjacent facing material and should be located in unobtrusive locations. If possible lights should be located behind balustrades and parapets so they are hidden from view.

10.83 The colour of light have a major impact on the attractiveness of the lighting scheme. Coloured lights are unlikely to be suitable for most buildings. In some cases the use of coloured light can constitute an advertisement and advertisement consent may be required. If consent is granted for the installation of lights the City Council may impose conditions to control the colour of light to be used. Intermittent lights are almost always unacceptable. Schemes should be designed carefully to minimise light pollution, especially in residential areas.

10.84 Consideration will also be given to highway matters or residential amenity in the determination of any application to floodlight a building.

LIGHTING UP THE CITY - A GOOD PRACTICE GUIDE FOR THE ILLUMINATION OF BUILDINGS AND MONUMENTS (SPG 1993) – extracts:

These guidelines will focus on the need to:

 light the exterior of only the best and most suitable buildings and monuments;

 keep fittings and installations as discreet as possible;

 avoid physical damage to listed buildings;

 ensure the use of proper light and luminance;

 properly and sympathetically highlight architectural character and details (including works of art) of the buildings concerned.

One of the main aims of the guidelines is to help avoid and identify badly designed schemes. These are schemes where:

 the lighting units and fittings are too prominent and visually damaging to the architectural character of buildings;

 the light itself is either too bright or not bright enough, is inappropriately designed and of the wrong colour for the building material;

 lighting units or fittings are poorly related to the architectural character of the building or monument;

 consideration of residential amenity and the use of the highway is ignored when lighting schemes are designed.

Buildings of Architectural Merit

Generally the City Council will only encourage the illumination of buildings of high architectural merit, and this should be placed firmly in its townscape context.

Consideration will be given to whether the building is an individual or part of a cohesive group or terrace. If the latter is the case then the City Council would expect to see proposals for the coherent lighting of the whole group.

Design and Installation

Exterior lighting schemes will only be acceptable where the lighting units and associated wiring are entirely discreet if not completely hidden. This is particularly important where buildings are either listed or form an important element of a conservation area, as insensitive installations can be to the detriment of their daytime character and appearance.

Initial design will often be based on what might give the most attractive night time effect; however, the type, location and size of lighting units must be carefully considered.

At the design stage it is helpful to use and present illustrative techniques that clearly and accurately communicate the design concept to all parties. It is possible to make accurate predictions of the potential lighting effects and levels of illumination of a scheme (colour, beam angle, light wash, shadow etc.) through the use of illuminated models, sketches and computer modelling.

Lighting units should be as small as possible so that they can be concealed behind architectural details such as balustrades, ironwork, columns, or located discreetly on cills, cornices and other features.

It is normally appropriate to paint out units to match the colour of the building material to which they are attached. At ground level units can be set flush in the ground surface, hidden in planting or concealed in area wells. Units should not be located on the face of buildings or in other prominent positions.

Location should not be chosen simply because they are convenient but because they have lighting validity and can contribute to a coherent overall lighting design. Locations and equipment should also be chosen so as to avoid glare and comply with accepted standards - glare being one of the most obvious problems of badly designed schemes.

The scheme should normally be installed by an approved electrical contractor to a predetermined design, under the supervision of a professional adviser. It must be installed with due sensitivity to the fabric of the building particularly if it is listed. It should be remembered that careless installation can cause problems of corrosion, electrolytic reaction, staining, cracking and failure of stone, terracotta, stucco and brick buildings and damage to fragile parts of such buildings.

The design of the scheme should allow for ease of maintenance and repair. Units and their controls should only be located where they are easily accessible, unless this is done schemes often fall into disuse because it is either too difficult or too expensive to undertake routine maintenance of lamps and cable routes. Festoon lighting will not normally be acceptable.

Lighting Technique

A lighting design should be consciously developed to take into account the important features and context of the building. In this respect brightness and contrast are the most critical elements of any lighting scheme.

Many buildings are so overlit that the brightness is painful to the eye and makes architectural appreciation of a building difficult. Lower levels of light allow more sophisticated and sympathetic renderings which can also create attractive contrasts between light and shadow thus enhancing the appreciation of a building.

Brightness can be assessed either objectively, by measuring the technical brightness of the surface, or perhaps more importantly subjectively, i.e. the perception of the lighting scheme by the observer. Subjective brightness is the key effect to establish and design for and depends upon the position of the observer, the brightness of the surroundings and adjoining exterior lit buildings, and the objective brightness.

The Institution of Lighting Engineers provides detailed guidance on appropriate levels of objective light in an attempt to reduce unnecessary illumination and light pollution from urban areas. Light pollution is making observation of the night sky increasingly difficult.

The brightness of a lighting scheme should be based upon the brightness of a district in which the building is located. Schemes which involve brightness higher than the prevailing local brightness will not normally be considered appropriate.

Consideration should also be given as to how the proposals, relate to existing exterior lighting schemes, particularly where these relate to landmark or other dominant buildings (e.g. churches, end of vista buildings).

Normally buildings of domestic scale and appearance do not respond well to exterior lighting. However, grand commercial buildings, stations, churches, public buildings and monuments can be beneficially illuminated providing they are of architectural interest.

Many recent speculative developments lack sufficient architectural integrity or detail to benefit from exterior lighting.

As a general rule exterior lighting should draw attention to the fine architectural characteristics of a building. It should not be to advertise its presence as a commercial property, a practice which is causing growing concern.

The Twelve Principles of Good Exterior Lighting

Only illuminate buildings of architectural interest.

Lighting should not be used where it may intrude upon residential properties.

Lighting units should be discreet and should not compromise the architectural integrity of the building.

Schemes should accord with the special architectural features of the building.

Lighting should take account of nearby schemes and have regard to the total lighting effect in the area.

Installations should not damage listed buildings.

Schemes should minimise light pollution and maximise energy efficiency.

The quality and strength of the light should take account of the nature of the building materials to be illuminated.

Professional advice should be sought from lighting consultants and planners.

Management and maintenance programmes should be devised to ensure consistent and continued lighting display.

Schemes should be an integral part of new developments.

Planning and listed building consents should be sought where necessary.

Historic England

External Lighting for Historic Buildings (2007) - extracts

GENERAL CONSIDERATIONS

Should the building be lit?

If a real demand for lighting has been established in conjunction with the owners or custodians, then the designer must look to limit the amount of light to that strictly necessary to achieve the aims of the scheme.

Does the entire building need to be lit?

It is rarely necessary to light all the elevations of a building, some parts often being unsuitable or inaccessible for viewing. It is usually better to concentrate on the prime nearby and distant night-time viewpoints. As part of the design process distance, angle and position of the viewer should always be taken into account.

Is there a pattern or arrangement which should be featured?

It is often better to illuminate selected architectural and sculptural features such as pediments, columns, porticos or niches, rather than illuminating the whole building. External lighting to reinforce a building’s patterns can increase the appreciation of architectural details. Crosslighting, uplighting and backlighting should all be considered, although uplighting must be limited and well controlled to avoid light pollution.

Designs can be refined by the use of tight beam control; shutters or baffles can also help reduce night-time light spill. However, the latter solution is rarely acceptable in appearance during the day unless the fittings can be concealed.

This leads to the next question.

Where can external lights be positioned?

It is essential that all luminaires are inconspicuous, easy to install and maintain, and respectful of the historic fabric. Even though a lighting design may give the desired effect at night, if the floodlights cannot be effectively hidden from view or disguised, the scheme must be rethought.

One solution is to floodlight from a remote position. Luminaires can be positioned on nearby buildings or street furniture. Where there are trees and shrubs it may be possible to disguise lighting poles.

Are there any adjoining properties? Is light spilling from the surroundings?

Neighbouring properties and the surrounding area must be taken into account. In rural areas, with lower ambient light levels with which to compete, less light will be needed to floodlight a building. This is often overlooked in lighting scheme designs. This will reduce both the initial outlay costs and ongoing energy consumption.

How big and how clean is the building?

As well as the existing ambient lighting, the reflectivity of the building surfaces must be taken into account. This will be affected by the colour of the building materials, and how clean they are. The more reflective a building, the fewer luminaires will be needed and the less powerful they will need to be.

Are there environmental matters to consider?

Lighting can affect some animals (for example bats and owls) that make historic buildings their home. Some animals and their habitats are protected by law. Where proposed external lighting may affect such animals an impact assessment will need to be made, taking into account breeding, hibernation and points of egress and ingress. As well as the increase in light levels, the effects of installation and maintenance must also be taken into account.

What is the most suitable light source?

The choice of light source must take into account the colour and reflectivity of the building surfaces, the desired colour rendering, the colour or operating temperature of the lamps, and their effect on the building materials.

Street lighting designers have begun to move away from high-pressure sodium (SON) lamps to metal halide (HIT) lamps, which is to say from warmer, red tones to cooler, blue tones of the colour spectrum. When choosing floodlamps the designer must take into account both the colour and the level of the local street lighting.

To increase impact an interesting effect can usually be achieved by using a lamp of a type different to that being used for the existing lighting, and this can also reduce the necessary number of luminaires and their power rating. If there is any doubt as to which lamp should be chosen, then a small field trial will usually be enough to determine the correct type.

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