Future Use and Development of Bentley Priory Supplementary Planning Document
On behalf of: Harrow Council
In respect of: RAF Bentley Priory
Date: Bedford September 2007 Belfast
Cardiff Reference: Dublin 804006/R0008 DM Glasgow
Leeds
London
Manchester
Newcastle-upon-Tyne
London Audrey House, 16-20 Ely Place, London EC1N 6SN www.dppllp.com Tel: 020 7092 3600 Fax: 020 7404 7917 Email: [email protected]
1.0 Introduction
1.1 The Supplementary Planning Document (SPD) for RAF Bentley Priory has been prepared to guide the future use and development of the site. The RAF are de- commissioning the base in 2008 and Harrow Council have therefore commissioned the preparation of the SPD to ensure that any future development safeguards the important architectural, historic and cultural importance of the site and takes proper account of its important landscape and ecological character.
Preparation of the SPD
1.2 To prepare the draft SPD an assessment of the site was carried out taking full account of planning, heritage, landscape and ecological considerations in order to define the site’s character and to identify constraints on its future development and opportunities through which the heritage value of the site could be secured. The identified areas of constraint and opportunity are illustrated in an issues and options document which was the subject of public consultation in February 2007. The document was then progressed to a draft SPD stage which was subject to further public consultation in July 2007. The responses received during both periods of public consultation have been used to guide the development of the SPD, a summary of each set of responses and consultation process are contained within a consultation statement which is available from the Council. The document has been prepared alongside a sustainability appraisal which has been used to help assess the opportunities and constraints at the site and to support Harrow’s sustainability objectives. The sustainability appraisal also assesses the relevant local, regional and national planning policies and the potential impact of the SPD on sustainability objectives.
1.3 The individual and unique sensitivities of the site are addressed in detail within the sustainability appraisal. However, a clear indication of the issues that must be addressed for the future use and development of the site are illustrated by the existing planning policy designations, set out below:
• Green Belt • Area of Special Character
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• Grade II* Listed Priory building • Grade II Registered Historic Park and Garden
The following designations apply to land immediately adjacent to the site:
• Site of Special Scientific Interest • Site of Nature Conservation Importance • Local Nature Reserve
1.4 Tree preservation order (TPO) number 872 currently covers the whole site which is currently being reviewed to identify trees as individuals, groups and woodlands. Once confirmed, there will be a total of four tree preservation orders under the numbers 885, 888, 892 and 893.
1.5 The site has a rich history ranging from its association with the eminent architect Sir John Soane, the role it played in hosting leading artistic and political figures in the 1800’s such as Wordsworth, Scott and leading Tory politicians through to its use as the home of fighter command in the Second World War and associations with leading figures of the time including Air Marshall Dowding and Churchill. The heritage importance of the site is safeguarded by the Grade II* listing of the principal Priory building and the listing of the historic park and gardens.
1.6 In addition to its historic associations Bentley Priory also has notable landscape and ecology assets as a result of the development of a park in association with the Priory. This is reflected today with the historic park and garden designation of the site and land to the south. A Site of Special Scientific Interest (SSSI) lies adjacent to the south of the site known as the Bentley Priory Open Space, this site previously formed a part of the historic parkland. The site also enjoys additional local environmental and landscape designations as set out within Harrow's Unitary Development Plan (UDP).
PPG2- Green Belts
1.7 The site is identified as a Major Developed Site within the Green Belt under Policy EP35 of Harrow’s UDP. Annex C of PPG2 sets out guidelines for the possible development of such sites. Any potential development must respect the guidelines set out within PPG2 and take account of the wider green belt setting.
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The London Plan
1.8 Due regard should be taken towards planning policy set out within the London Plan and draft further alterations to the London Plan particularly with regards to the areas of sustainability, the green belt, heritage and accessibility. Further discussion of specific London Plan policies can be found in the sustainability appraisal.
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2.0 Overview of SPD
2.1 The SPD is to be used as a guide for potential future use and development of the site. The document is a key material consideration in determining the acceptability of detailed planning applications for the site. Harrow Council will not consider applications that do not include the level of detail considered appropriate for the sensitivities of the site and the SPD includes guidelines for the documentation that should be included with any subsequent detailed planning applications.
2.2 In terms of the content of the SPD sections 3 to 6 deal with the location and characteristics of the site and include a brief description of the key historic dates associated with Bentley Priory.
2.3 The document then deals with the vision for the site and the practical measures that have been identified within the SPD to achieve the vision objectives (sections 7 to 11). These are set out in four different sections dealing with the heritage, landscape, ecology and potential future development of the site.
2.4 Section 12 of the document includes details of the documentation that the Council will expect to be included within any detailed planning application and planning obligations that would be sought as a result of developing the site.
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3.0 Location
3.1 RAF Bentley Priory is on the northern fringe of the London Borough of Harrow situated upon the Harrow Weald Ridge making it a prominent location in the wider London context.
3.2 It can be seen clearly on the map extract opposite that the site falls within a green belt of land separating the urban areas of Bushey Heath to the north and Stanmore to the south.
3.3 The site sits between the Harrow Weald Common and Stanmore Common which are large areas promoting public access to the Harrow Weald Ridge.
3.4 In terms of transport links the site is served by both the A4140 and A409 and is also within close proximity of junction 4 of the M1 as illustrated on the plan extract opposite. Two bus routes serve the site (142 and 258), although the site is within an area categorised as low public transport accessibility (Zone 1) in the Harrow Unitary Development Plan.
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4.0 Characteristics of the Site
4.1 The site can be split into three zones in terms of characteristics:
Zone 1 4.2 The north of the site is largely characterised by open green spaces bounded by mature vegetation with a large area of hard standing 0.4 hectares in size. This area also accommodates the access to the site off the A4140. The area includes several small scale buildings e.g. the guard room and hard standing at the entrance to the site associated with its RAF function, and a vehicle servicing garage and bays in the north western corner.
Zone 2 4.3 The existing built environment is largely focused within a belt from east to west. The building line to the south is roughly in line with the rear elevation of the Priory building and extends northward encompassing the Priory and accommodation blocks built by the RAF which sit at the top of and beyond the incline of the Weald Ridge. In respect of design the existing buildings on the site have a variety of architectural styles ranging from the Priory building through to modern RAF accommodation blocks completed in the late 1990’s. The eastern tip of this section accommodates a Cold War bunker of circa 40,000 sq ft. This is buried into the face of the hill at the eastern end of the site. This has an effect on the surface topography and there is some limited planting on top of the bunker area.
Zone 3 4.4 This area includes mature vegetation along the southern boundary and the formal Italianate gardens which sit to the south of the Priory building looking out towards London. This area includes some of the densest vegetation on the site whilst also opening up glimpse views to and from the borough of Harrow.
4.5 The existing built footprint at the site, as surveyed by the owners, totals 12,730m2.
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5.0 Historical Background
5.1 The Priory has a rich cultural history the main periods of which are set out below:
5.2 Saxon- Located on the highest point in the historic county of Middlesex it is possible that the site was occupied in ancient times. The name “Bentley” is of Anglo-Saxon origin and suggests the immediate area will have had an established agricultural population by at least the late Saxon period.
5.3 Augustinian Priory- This history of the estate can be traced back to 1170 when the original Augustinian Priory was founded by Raulf De Glanville.
5.4 James Duberly- James Duberly bought the Priory buildings and the 329 acre estate in 1776. It is reported that Duberly demolished the ruins of the Priory and built his house on higher land within the site to benefit from views south to St Mary’s Church at Harrow on the Hill and towards London.
5.5 The Marquess of Abercorn- Architecturally, it is the work of Sir John Soane, for the Marquess of Abercorn which is of most significance and particularly warrants the grade II* listing. This period also saw associations between the Priory and Wordsworth, Scott and much of the Tory party of the time.
5.6 Dowager Queen Adelaide- The Marquess died in 1818 leaving the Priory to his 7 year old grandson James Hamilton. He leased the property to the Dowager Queen Adelaide, widow of William IV, between 1846 -1849 who died at the property.
5.7 Sir John Kelk- In 1852 Sir John Kelk, a prominent engineer and contractor, purchased the property. He added the portico to the south elevation, a conservatory and clock tower to the west and laid out the Italian terraced garden, significantly altering the southern aspect.
5.8 Fredrick Gordon- In 1882 Frederick Gordon purchased the Priory estate and the building was converted into a hotel.
5.9 The Girl’s School- In 1908 the Priory was sold again following the failure of the hotel
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and leased by Stanmore Estates Ltd for use as a girl’s school.
5.10 The Royal Air Force- In 1926 the Air Ministry bought the Priory and 40 acres of the surrounding parkland. Importantly, from 1936 to 1968 the Priory served as the headquarters of Fighter Command associating the site with figures such as the King and Queen, Eisenhower, Churchill and Air Marshall Dowding.
5.11 Post World War II- Fighter Command remained at Bentley Priory until 1968 when it was amalgamated into Strike Command to become HQ 11 (Fighter) Group. During this period Bentley Priory played a central role in countering the threat posed by the USSR and the Warsaw Pact nations. The command bunker was substantially rebuilt in 1982 and much of its original form was lost.
5.12 1990’s- Latterly the site and buildings have been used for administrative, training and storage facilities with significant amounts of barracks accommodation.
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6.0 The Historic Landscape and Setting of the Listed Building
6.1 As with most great houses the landscape setting must be seen as an integral part of the whole. The setting of a listed building is often an essential part of the building’s character, especially if a garden or grounds have been laid out to complement its design and function. The RAF site is the northernmost part of the wider registered parkland that, until 1926, formed the estate for the Bentley Priory House. A number of original elements of the Priory’s landscape have remained largely unchanged.
6.2 The historic park and garden is noted as an C16th estate enlarged and improved in the late C18th by James Hamilton, ninth Earl and first Marquess of Abercorn who corresponded with Sir Uvedale Price (an acquaintance of Repton). Price and William Sawrey Gilpin influenced the design of the park in the early part of the C19th.
6.3 Much of the perimeter of the original estate was sold off for building in the 1920s and the greater part was bought by Middlesex County Council and became a public open space. This area surrounds the Summerhouse Lake, an artificial water body in the picturesque style.
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7.0 Vision for the Future of RAF Bentley Priory
Harrow Council's overarching vision for RAF Bentley Priory is to ensure that the historical and environmental integrity of the site is conserved and enhanced. Any future development must safeguard the important architectural, historical and cultural value of the site and take proper account of its significant landscape and ecological character. Linked to this overarching vision, the following aims and objectives must be considered and achieved:
7.1 Sustainable development – In the context of the green belt, listed building and historic park and garden setting it is vitally important that any future development conforms with the objectives set out within 'PPS1 – Delivering Sustainable Development'.
7.2 Distinct areas – Due to the historical development of Bentley Priory there are several distinct areas of the site with differing sensitivities in terms of historical, landscape and ecological factors. There are clear opportunities to improve the general environment of the site which benefit the setting of the listed building, benefit the historic parks and gardens setting and improve the ecological properties at the site (notably the woodland on the east and west sides of the site), whilst also allowing the development of less sensitive areas which principally (or previously) accommodate older buildings and hard standings associated with the RAF use.
7.3 The Battle of Britain and public access – The public consultation revealed the strong sense of importance that people placed upon the Priory’s RAF associations with specific reference to the Battle of Britain. It is clear that there is a strong public feeling alongside specialist veterans and interest groups which support the preservation of the most important buildings or parts of buildings associated with the RAF use of the property. The most important historic spaces within the Priory building where public access should be provided have been identified on a plan attached to the end of the report.. It is also clear from the consultation process that the public would like some form of access to the areas which relate to the Battle of Britain.
7.4 Bentley Priory wider history – In historical terms it is also important that any potential development respects the wider history of the Priory with its historical associations
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harking back to Saxon times.
7.5 Site of Special Scientific Interest (SSSI) and public access – A SSSI lies immediately to the south of the site which the Public would like to see continually protected. This was most apparent in the response to the proposed footpath links to Bentley Priory Open Space and their management.
7.6 Bentley Priory’s Green Belt status – Given RAF Bentley Priory’s ‘Major Developed Site’ status in green belt terms it is important that any potential future development accords with the guidance set out within Annex C to PPG2.
7.7 Landscape – The site is situated on a prominent position of the Harrow Weald Ridge giving views of London to the south. This landmark setting of the site should be enhanced through appropriate landscape management schemes and supported with the sensitive development, redevelopment and conversion of the built fabric of the site.
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8.0 Achieving the Heritage Vision
8.1 The principal Grade II* listed building consisting of the mansion altered and remodelled by Sir John Soane with later C19th additions by Sir John Smirke is the key element of the site which should be retained and restored. Appropriate re-use for purposes that accord with its special architectural or historic interest, both externally and internally, specifically Soane’s suite of rooms with their later RAF related historical interest, will be crucial to this.
8.2 The following heritage opportunities should be sought in planning any potential development or redevelopment on the site which should be viewed in association with the heritage plan attached to the end of the report.
Opportunities 8.3 Retention of ground floor suite of rooms for public access
Re-use of the suite of ground floor rooms of the main building, as existing, for public purposes that respect and retain their special interest, with limited potential for sensitive alteration. Given the architectural importance of Soane’s work and the historic importance of the RAF’s use in World War II, the opportunity for public access must be secured.
8.4 Sensitive conversion
Sensitive conversion within the overall structural plan form of the basement and first floor spaces of the main building, for appropriate alternative uses, to either support the use of the ground floor or as a discrete, independent use.
8.5 Restore the historic fabric
Removal of the 1950s billiard room and restoration of the retained fabric and other improvements to the historic parts of the building, such as restoration of the fenestration to the southern elevation to the original pattern.
8.6 Development potential
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The opportunity exists to refurbish, redevelop or demolish the attached 1928 accommodation block (building 267) with the potential to create a more subservient building-line in relation to the principal listed building. Buildings 7 to 11 have some architectural merit but redevelopment may be possible, subject to the appropriate design of any new building. The former Gateway to the walled garden (part of building 8) should be retained or relocated elsewhere on site. There may be scope for benefits to be derived from some limited development within the courtyard area to the west of building 1 and north of building 7 and 267, again, subject to appropriate design and other planning considerations.
8.7 Ancillary supporting development
Potential for some limited redevelopment in defined areas, close/linked to the house, to provide any necessary ancillary accommodation/facilities required to support re- use of the main house, subject to improving the overall setting of the listed building.
8.8 Removal of unlisted buildings
Potential exists to remove ancillary unlisted buildings, structures, hardstandings and access roads, mainly to the east and west of the listed building (Buildings: 2, 3, 8, 14, 16, 17, 27, 33, 36, 87, 88, 263, 264, 266, 268, 270, 272, 274) to both improve the immediate setting of the listed building and release areas for redevelopment in parts of the site previously developed by the RAF, and discreet areas to the north, east and west.
8.9 Improving the setting
There are three curtilage structures which are considered to be listed as they date from the first part of the 1940s and fall within the curtilage of the principal listed building. They are not, however, considered to be of any significant architectural or historic interest and their removal could enhance the setting of the principal listed building. (Bldg 258, a prefabricated office to the east of the listed building and buildings 259 and 262, simple shed-like structures sited in the grounds to the south). Listed Building Consent would be needed for the removal of these structures.
8.10 Creating space around the principal listed building
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Redevelopment adjacent to the principal listed building should (i) improve the overall ‘setting’ space between new built form and the listed building; (ii) respect the character and appearance of the listed building; (iii) be located no further south than the existing building line of the listed building; and, (iv) ensure that the north elevation of the listed building remains dominant in its new landscape setting particularly as seen in the approach along the original carriage driveway (see below). Similarly, aspects of the historic landscape which provide the immediate setting for the listed building are capable of repair and reinstatement, improving the relationship of the buildings to the designed landscape. Specifically:
8.11 Historic approaches
Retain and enhance the formal approach from the north, through reinstated woodland and then open parkland to the porte-cochere of the listed building. Reinstatement of the initial woodland approach would offer the opportunity to screen a discreet area for development and include removal of the ‘station car park’ and associated bunds, the communication tower and the tennis courts.
8.12 Garden restoration
Restoration of the Italian Terrace Garden to an appropriate scheme from the later C19th, research has been undertaken into the historic gardens and reference should be made to the report prepared by Jennifer Potter on behalf of the Architectural Association. It should be noted that there are numerous historic garden objects within the terrace area, many of which will be listed in connection with the principal listed building.
8.13 Restoring wider views of the listed building and Italian terrace and links with Bentley Priory Open Space
Restore views from the listed building and Italian Terrace Garden to Bentley Priory Open Space and Harrow on the Hill. Providing a visual link with the former parkland setting of the house. Strengthen the links between the listed building and Bentley Priory Open Space through improving the nature of the boundary treatment between the two, enhancing visual connections and reducing the C20th screen planting.
8.14 Cold War bunker
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English Heritage has investigated the bunker in terms of potentially scheduling the structure as an ancient monument or designating as a listed building, and has recently determined that the bunker is not suitable for either designation. The bunker will therefore be decommissioned and sealed when the RAF vacate the site. This will be carried out to a scheme agreed with the Council to ensure its continuing presence does not prejudice any future use of the site.
8.15 Design quality
Achieving a high design quality, based on a full understanding of the site and its character and history, will be a key consideration in any future proposal. This will need to acknowledge the particular characteristics of distinct areas within the site, not least the area around the principal listed building. Development should also be in accordance with Harrow Council’s UDP policies on design and with guidance in PPS1 and PPS3.
8.16 Archaeology
Any proposals will need to be sensitive and sympathetic to the archaeological potential of the site and should take full account of the requirements of PPG16.
Due to the above mentioned opportunities inherent with the principal listed building and historic park and garden, the Council will require that any future development proposals are supported with justified statements and conservation plans dealing with the effects upon the historic fabric of the site and design.
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9.0 Achieving the Landscape Vision
9.1 In respect of the Historic Park and Garden setting of Bentley Priory there are a number of potential landscape benefits the Council would seek to secure from any future development of the site. These are set out below with the aid of the landscape plan attached to the end of the report:
9.2 Potential for development within areas of high visual containment
The established vegetation structure affords a high degree of enclosure ensuring views into the site from the wider setting are limited. The existing treescape will also create a significant degree of integration and visual containment for proposed development ensuring that views into and out of the wider Green Belt setting are not detrimentally affected. Potential areas for future development have been identified at section 11.
9.3 Potential for development within areas influenced by existing built form.
The key buildings to be retained provide an established setting for any proposed development ensuring that new built form sits within an existing built environment. As such any development proposals should not encroach upon existing green areas on the site, or mature trees subject to a Tree Preservation Order (TPO).
9.4 Restore the parkland and woodland setting to the north of the main house
The removal of the existing car park, earth mounding and the modern evergreen tree screen around the car park will open up vistas towards the main house when approaching along the driveway from the north. Together with the introduction of new planting, the reinstatement of the parkland and woodland landscape to the north of the main house will enhance both the setting of the listed building and any new development and also enhance the approaches to the site from the north along the drive. This would restore the parkland and woodland setting to the north of the main house in accordance with the original layout of the Priory’s grounds. The Council wishes to see the removal of the two telecommunication masts that currently detract from the wider landscape and historic setting.
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9.5 The key trees within the site should all be retained.
There are a substantial number of mature trees within the site which create the setting for the historic house and park. Key trees will be identified by any potential developer and retained in line with British Standard 5837 to ensure that the character of the parkland and its setting is maintained. This treescape will also create a high quality setting for new development. It should be noted that the Council will be confirming four tree preservation orders to cover individual trees, groups and woodland areas.
9.6 Introduce a parkland management scheme to the area to the south of the listed building
9.7 Proposals for the development of the site will be expected to be accompanied by management schemes to include tree removal and replacement to enhance the setting of the listed building and also enhance intervisibility between the main house and the wider setting including the original park that now lies beyond the sites boundaries.
9.8 The management of the vegetation structure to the south of the main house will enhance views towards Bentley Priory Open Space and to Harrow beyond from the listed building and terrace garden. The main house forms a key element within the wider context, the management of this planting would ensure that the listed Bentley Priory building remains part of the wider visual envelope. Retention of key vegetation structure will ensure that the integrity of the parkland setting is maintained.
9.9 Following development it is important that the parkland, formal gardens and areas of woodland and new woodland plantings are properly managed. The management agreement will be secured through a section 106 agreement that will oblige future owners and occupiers of the site to continue to support the management of the wider site. Planning obligations and section 106 agreement issues are discussed in more length at section 12.
9.10 Footpath links around Bentley Priory Open Space
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There are opportunities to provide greater public access between the site and the adjoining Bentley Priory Open Space. The London Loop runs to the south of the site through the Bentley Priory Open Space and there are opportunities to improve visual access to the Priory site from this footway. Limited footpath links between the site and the Open Space could be created in the south-east corner, but any footpath would not give access to the wider grounds of Bentley Priory which will remain restricted. These areas would only be open to the public as part of a visit to the main house. The location of the footpath links will be dependent on their impact upon existing and proposed elements within the Bentley Priory site, while the links to existing footpaths will ensure compatibility with the adjoining Bentley Priory Open Space. Care needs to be taken in balancing the advantages of greater public access with the need to protect and maintain the ecological value of the designated SSSI.
9.11 Public access in the context of the proposed development areas is dealt with in more detail at paragraph 11.31 of section 11.
9.12 Potential to re-establish link with Glenthorne site (UDP proposal site 23)
There is potential for planning gain monies to be used for off site improvements in the landscape linkage between the Glenthorne site and Bentley Priory Open Space. This would help re-establish links with the Glenthorne site which has in the past played a role in both the landscape and heritage setting of Bentley Priory as a whole. The Glenthorne site is illustrated on a plan attached to the end of the report. and will be included within and added to the Bentley Priory Open Space in accordance with the proposed use for Glenthorne set out by the Council's adopted UDP.
9.13 Command bunker
The area of land around the Cold War bunker at the eastern end of the site should be opened to the public and an out-door interpretive display provided to explain the origin and purpose of the bunker. A commuted sum for the ongoing maintenance and upkeep of this area as part of the wider Bentley Priory open space will be required as part of the section 106 agreement relating to development of the wider site. Planning obligations and section 106 agreement issues are discussed in more length at section 12.
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10.0 Achieving the Ecological Vision
The Council will seek the retention and enhancement of existing ecological assets on and around the site. The following factors set out the issues that should be addressed within detailed schemes for the site by way of management agreements, planning condition or section 106 agreements and should be read in association with the ecology plan attached to the end of the report.:
10.1 Designations
Part of the southern boundary of the site is constrained by the Bentley Priory Open Space and the Site of Special Scientific Interest (SSSI), Local Nature Reserve (LNR) and Site of Nature Conservation Importance (SNCI) which receive, protection under national legislation. Best practice will need to be strictly adhered to during the construction phase of any future proposals and the ongoing future use of the site in order to avoid any damaging impacts on the special interest features of these statutory and non statutory designations. Any increase in usage of the SSSI/ LNR as a result of development will be balanced against the benefits that may be derived from encouraging greater public access to the open space and RAF Bentley Priory. Recreation space for residents within the redeveloped RAF site would relieve pressure on the SSSI.
10.2 Habitats
In habitat terms, the site is relatively unconstrained with the majority of habitat areas considered to be of low to negligible ecological interest. However, there is the opportunity for nature conservation features to be enhanced in line with PPS 9 (Biodiversity and Geological Conservation) The areas of scrubland and broad-leaved woodland in the south of the site and a number of mature trees are of ecological interest and any future proposals should protect, retain and enhance these features. Habitats also exist within certain trees and buildings, ponds and rank grassland within and adjacent to the site and should be protected, retained and enhanced where appropriate.
10.3 The highly invasive species Japanese Knotweed is present within the site (see Ecological plan). Best practice should be followed during any activities that could London Audrey House, 16-20 Ely Place, London EC1N 6SN Tel: 020 7092 3600 Fax: 020 7404 7917 Email: [email protected]
potentially cause the further spread of this undesirable species. Any future development must take measures to eradicate this plant from the site, which should be included within ongoing management plans.
10.4 Species
The baseline survey work has identified that the trees & buildings; ponds; and rank grassland; within/adjacent to the site have the potential to support bats; Great Crested Newts; and common reptiles, respectively. Bats and Great Crested Newts are fully protected under European and national legislation, while common reptile species receive partial protection at the national level. Significant species may also exist within the woodland and scrubland areas around the site. Further survey work is needed at the planning application phase to establish the precise extent to which protected species would constrain any future development and to determine the need for any mitigation. It is also noted that common bird species occur at the site, which receive protection while nesting.
10.5 Location of enhanced access to Bentley Priory Open Space
Greater public access between the site and the existing pathways within the adjoining Bentley Priory Open Space is sought. This measure would facilitate the public’s enjoyment and appreciation of the natural features of the Open Space and LNR, in line with the objectives of this ecological designation. Linking in to existing pathways must ensure compatibility with the SSSI’s ecological interest features and the exact positioning of the new access points will need to be carefully considered so as to respect and protect the existing interest. The provision of targeted access to/from the site, together with the provision of new areas of nature conservation interest within the site, will potentially act to divert some of the existing recreational use from the SSSI. Specific access requirements are dealt with in more detail at paragraph 11.31 of the report.
10.6 Habitat creation
New habitat areas of benefit to nature conservation, which will enhance the existing and adjacent ecological setting are included within the SPD. Such areas could include enhancements such as wildflower planting, appropriate woodland planting and a number of species specific measures, e.g. the erection of bat and bird boxes. In
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addition, with the erection of interpretative panels these areas could function as an educational resource as well as areas for informal recreation. Subject to establishing the financial and physical feasibility and the prioritisation of Section 106 funding, this site could provide a location for an ecology/environment centre. Details for the nature conservation enhancement of areas identified on the SPD are to be set out within planning proposals for the site including management for their future maintenance.
10.7 Management
The sensitive management of the woodland at the site, including selective thinning and new native planting together with the other retained and newly created habitats will enhance the ecological interest of the site. In addition, the removal of Japanese Knotweed within the woodland and elsewhere within the site will provide an ecological enhancement. The Council seeks future proposals for the site to include ecological assessments for selective thinning of woodland to the south of the Priory including management plans for their future maintenance.
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11.0 Opportunities for Future Development
11.1 There are opportunities to improve the environment at Bentley Priory and there are areas which should be protected.
11.2 Taking account of the existing assets at the site and planning policy considerations we have identified possible re-uses for the Priory and adjoining buildings, and a number of areas for potential future development all of which are highlighted on the attached plans.
11.3 The Council will not accept piecemeal development of sections of the site because of its special nature. Any potential future development must be brought forward in a comprehensive development scheme for consideration.
11.4 Priory and adjoining buildings (Building numbers: 1, 112, 267, 7, 8, 9 , 10 , 11)
Detailed issues regarding opportunities and constraints for the Priory building have been addressed within the Heritage section (8) of this report.
11.5 In terms of the Priory building the sensitivities that exist relating to its heritage assets and the surrounding landscape and ecological features rule out a number of potential uses as inappropriate. Any scheme must ensure the preservation of the historic heritage value of the site and ensure public access, at an appropriate level for the historic core of the building associated with its RAF heritage. Such public access should allow for both casual visitors and ceremonial use of the suite of rooms shown on a plan attached to the end of the report and the Italian Garden Terrace.
11.6 As such the Council have identified the following uses which may, in combination be appropriate:
• Residential; • Museum/ exhibition; • Hotel/ Conference centre/ corporate function suite; and • Residential care home for the elderly.
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11.7 The principal objective is to secure a museum or exhibition use for the key suite of rooms and spaces shown on a plan attached to the end of the report. In conjunction with a museum/ exhibition use of these historic rooms the first preference is for residential development which can achieve the most appropriate and discrete relationship in terms of operating within the same building envelope using the existing building sub divisions. Car parking provision to serve the museum and other residential functions of the Priory itself should be located to the west of the main house and screened from the carriage driveway. For any uses requiring significant car parking areas these would have to be carefully planned, potentially within area 4 or located in such a way as to avoid impact upon the parkland or wider setting of the Priory itself.
11.8 A key question during the public consultation asked, how the ground floor suite of rooms relating to the Battle of Britain should be retained. The overwhelming response to this question was support for a fixed and permanent museum open daily to the public and visitors. Whilst full museum use of the Priory is the public’s preferred option for the Priory building, concerns have been raised by key stakeholders that full time museum use of the building associated with the Battle of Britain may not be viable. As such it is important that other options are not discarded e.g. part time opening or shared use of the key historic rooms should a full time museum or exhibition prove unviable. The Council fully supports public access to the key historic areas of the site in accordance with the SPD’s vision, However, schemes for public access to the historic rooms must be viable in order to maintain the building’s fabric and its special character.
11.9 Any future development proposals for the Priory building will have to include information regarding how the building will operate and how the interaction between the different uses incorporated within the building will be managed.
11.10 The Council will require a financial open book approach in terms of illustrating how the museum usage will be managed on receipt of any development proposals for the Priory building to ensure that its special historical assets can be preserved for future generations to enjoy.
11.11 Funding from redevelopment elsewhere on site
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A key part of the strategy for this site lies in realising some development value in order to cross – subsidise and to maintain the sites historical associations, to preserve those elements of its heritage, restore the landscape setting of the site and maintain the ecological assets associated with the area. Rather than promoting re- use of the existing buildings for alternative uses (excluding the historic Priory itself), the strategy focuses upon identifying where development on the site could best be located. Notwithstanding the existing position of buildings, key issues would be enhancement of the setting of this green belt site, , the setting of the historic house, its parkland and the high quality landscape within which the Priory sits. PPG2 concerns development within the Green Belt within which guidance at annex C identifies the parameters by which the development of major developed sites in the Green Belt will be determined. Paragraph 4 of annex C sets out the parameters for redevelopment which states:
‘(a) have no greater impact than the existing development on the openness of the Green Belt and the purposes of including land in it, and where possible have less; (b) contribute to the achievement of the objectives for the use of land in Green Belts(paragraph 1.6 - see also paragraph 3.13); (c) not exceed the height of the existing buildings; and (d) not occupy a larger area of the site than the existing buildings (unless this would achieve a reduction in height which would benefit visual amenity).’
11.12 It is important to note that permitted development constructed with the benefit of crown immunity during the RAF's ownership of the site does count as developable footprint in PPG2 terms with specific reference to annex C set out above.
11.13 Planning Obligation Contributions
Categories for planning obligation contributions are dealt with section 12 of the document.
11.14 Redevelopment options elsewhere on site
The redevelopment of the site favours the removal of some areas of built development; the sensitive replacement of other buildings or parts of buildings and the creation of new buildings, to replace those lost, at different locations within the site. The existing building footprint on the site, as surveyed by the owners is
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12,730m2 which includes the listed building but does not include the command bunker. At the planning application stage, a comprehensive and independently audited footprint schedule will be required. The footprint figure is significant in respect of the guidance set out within PPG2, Annex C in terms of major developed sites in the green belt.
11.15 This process, taking account of heritage, landscape, ecological and planning considerations has led us to identify four key areas for development. These are illustrated along with other objectives addressed in a plan attached to the end of the report..
11.16 In general terms the SPD encourages the re-use or redevelopment of the existing buildings on the site in these areas. There should be no overall increase in the footprint of built development of the site. Where existing buildings fall outside of the areas identified they should be removed and their footprints can contribute towards the development footprint within the four areas identified for development.
11.17 Area 1- West gateway
This area currently accommodates a vehicle service building and an area of hard standing, it is bounded by mature vegetation and there is some dispersed tree planting. Adjacent to the south west and north east boundaries of the site are residential dwellings while the north east boundary is adjacent to the A409. In terms of visibility the area is well enclosed by vegetation and does not have any views of the wider site, whilst the hard standing within the area restricts the amount of vegetation that can grow limiting its ecological potential.
11.18 In terms of development suitable proposals on this area would be for residential development similar in scale and massing to detached housing (two– three storeys in height, including rooms in the roof) with garden enclosures. Access would be from the Bentley Priory spine road with the orientation of the houses facing into the site and the protection of trees to the junction corner and tree screen to Common Road. This would ensure that proposals reflect the character of development on the existing Common Road frontage.
11.19 Area 2- East gateway
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In respect of the current usage area two is relatively undeveloped with some dispersed shrub and tree planting. The area is not visible on entering the site off the A4140 and due to existing boundary treatments and vegetation it is also largely screened from residential properties towards the north east. With regards to existing built form on this part of the site this consists of the RAF’s guardhouse at the entrance to the base. As illustrated on the future use and development plan attached to the end of the report. the opportunity to put landscape planting to the south of any proposal would help to establish the original woodland entrance to Bentley Priory.
11.20 This area is regarded as suitable for residential development similar in scale and massing to detached housing (two– three storeys in height, including rooms in the roof) with garden enclosures screened from beyond the site in keeping with the existing street scene on the A4140. In developing this area appropriate landscape planting will be expected to be included to the south of the area to ensure that it is largely invisible to the south from the rest of the Priory site.
11.21 Area 3– West of Priory
The buildings here are inter-dispersed with limited planting including mature trees and areas of hard standing. The three main buildings numbered 2, 16 and 14 are all RAF accommodation blocks built in 1998 to a similar architectural style of between two to three storeys in height. Although the properties do not have any particular architectural merit they may be suitable for re-use. In terms of boundary treatments the western edge is heavily planted with mature vegetation restricting views out of the site while to the south some glimpse views are available of the adjacent parkland. Views of the complex of buildings to the west of the Priory are visible, although it is largely detached from the principal listed buildings. Surrounding the existing buildings is a large amount of hard standing and grasscrete demarcated for parking and circulation.
11.22 This area is regarded as most suitable for the principal zone of new development. In terms of scale and massing, development should not be greater than two to three storeys in height, with the principal built form being residential flats rather than individual dwelling houses. Buildings of significant uniform mass should be avoided or broken down or arranged in such a way as to avoid large massing out of character with the green belt setting. With regards to orientation, development within the area should reduce in visual bulk to the east and the development must accommodate London Audrey House, 16-20 Ely Place, London EC1N 6SN Tel: 020 7092 3600 Fax: 020 7404 7917 Email: [email protected]
significant existing trees. Amenity space must be predominantly shared to avoid individual garden enclosures which would affect the open nature of this green belt site. There would be scope for some dwellings to accommodate individual amenity enclosures, for example, ground floor flats, although any such enclosures should have no visible impact on this green belt site. The design must also take into account the prominent nature of certain sections of the area on the Harrow Weald Ridge. Any development proposals would also need to include sufficient detail of the area from long distance views to the site from the south.
11.23 Area 4– East of Priory
Area 4 is extremely well protected from views outside and within the site, due to the topography and planting surrounding the area. The existing office accommodation does not have any particular architectural merit, although the modern 274 building may be suitable for re-use. Building 274 is well screened but it is visible from the principal listed Priory building, so that any replacement buildings would have to be of an appropriate high quality design, improving on the current buildings appearance.
11.24 Building 263 has been incorporated within the area 4 designation. Although building 263 shares a similar architectural style to building 274, the western end of the structure is in close proximity to the listed Priory structure.
11.25 Development usage in this area of the site should be in keeping with the main use of the house itself, options for which are discussed above in paragraphs 11.4 to 11.10
11.26 Whilst building 258 is a listed curtilage structure it is considered to be have no significant historic or architectural interest and its removal would enhance the setting of the principal listed building.
11.27 Given the proximity of this area with the grade II* listed Priory building any potential development should be of a high quality design, particularly for any development in the location of the existing building 263. The Priory building is the key architectural building on the site, so any new development would need to be visually subservient.
11.28 Given the existing topography of the area, development of a scale and massing similar to three storey flatted or housing development would be appropriate.
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11.29 With regards to planting the existing planting screens along the northern boundary of the site adjacent to area 4 and the planting screen to the south must either be retained or suitably replaced.
11.30 The holistic treatment of area 4 in terms of the design, scale, massing and planting is a core requirement and must be clearly illustrated within supporting information.
11.31 Public access to Bentley Priory Open Space
During the issues and options consultation two points of potential public access on the southern boundary of the site were identified. A number of responses were received from the public detailing their concerns regarding the potentially harmful effects that intensification of the existing footpath system would have upon Bentley Priory Open Space (and the SSSI in particular). However, there were a similar number of responses supporting increased permeability through the site.
11.32 Harrow Council are seeking greater public access as illustrated on the area plan. Development proposals for the site will have to include suitable management plans and measures to ensure that Bentley Priory Open Space (particularly the SSSI) is not adversely affected. Any developer would need to consult with Natural England and the Bentley Priory Open Space Warden to ensure the public access is suitably placed and managed. Approval will need to be obtained from Natural England before any alterations are carried out.
11.33 It has been noted that in managing the grassland habitat within the SSSI to the south livestock grazes on the land during certain parts of the year. This would ensure that any boundary demarcation of the site would have to be stock proof fencing. The existing boundary line is marked with military fencing which is not in keeping with the general surroundings. The Council suggest that a typical timber fence would be suitable in this location in keeping with the special nature of the listed Priory building and historic park and garden.
11.34 Transport access to the site
The site is poorly served by public transport. The only service to the site is by the 142 and 258 bus services which stop along The Common and Common Road
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respectively linking Bushey and Stanmore. As such it is likely that motor cars would be a favoured transport mode to access any development on the site. It is important that any application satisfies national, regional and local planning transport policies in terms of public and private transport provision including the provision of suitable bicycle storage.
11.35 Sustainability
In accordance with the Council's sustainability objectives for the site any potential development must demonstrate that sustainability issues have been addressed which could include:
• Promotion of sustainable waste behaviour • Promotion of renewable energy options • The conservation of energy during development and the lifespan of any potential buildings through design and the choice of materials • Conservation of the natural environment
11.36 Access Issues
11.37 Any potential development also needs to promote inclusive access and design in accordance with national planning guidance, the London Plan and Harrow's planning policy framework.
11.38 Affordable Housing
11.39 Whilst planning requirements are set out in detail within the following section it is important to take note of Policy 6A.4 of the London Plan which states:
“Affordable housing and public transport improvements should generally be given the highest importance with priority also given to learning and skills and health facilities and services and child care provision”.
11.40 The above mentioned Policy clearly defines the priority for planning obligations, although regard must also be had for the other objectives of the SPD and the requirements set out within section 12 for any potential development of the site. London Audrey House, 16-20 Ely Place, London EC1N 6SN Tel: 020 7092 3600 Fax: 020 7404 7917 Email: [email protected]
Proposals for the site will need to demonstrate how the affordable housing requirements, in line with Council and GLA policy, can be provided. In determining how the affordable housing is to be provided, the Council will take into account the location of the site in terms of public transport and sustainability and its sensitive heritage, landscape and ecological characteristics.
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12.0 Planning Requirements
In the context of the sensitivities of the site any potential planning applications must include the following supporting evidence in accordance with national planning policy, the London Plan and Harrow's adopted planning policy framework (the following list is not exhaustive):
• Planning Statement; • Design and Access Statement; • Statement of Community involvement; • Heritage Statement (including detailed analysis of historic development, archaeology and a survey of existing position); • Heritage conservation management plan for the entire site; • Environmental Impact Assessment (including screening and scoping reports and the impact on Bentley Priory LNR and SSSI); • Landscape Statement (including survey of existing position and visual impact assessments); • Ecological Statement (including survey of existing position and the impact on Bentley Priory LNR and SSSI); • Transport Statement (including travel plan and survey of existing position); • Supporting drawings and illustrations including detailed plans and information for the listed building and other heritage elements ; • Topographical Survey; • Surface water flood water risk assessment in accordance with PPS25 (Flooding); • Contaminated land survey • Energy, utilities (including sewerage and drainage) and Sustainability Statements • Affordable housing statement • An comprehensive and independently audited footprint schedule of the existing buildings; • Vegetation survey to include trees, hedges and shrubs to be retained and removed; • Landscape scheme providing full details of hard and soft landscape works; and as part of a BS:5837 (2005) trees & development assessment, the following will be required:
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• A tree survey showing trees to be (a) retained and (b) proposed for removal; • A Tree Protection Plan; and • A Arboricultural Method Statement for any parts of the development that may impact on trees.
Applicants may wish to consider whether a scale model of the proposed development would assist fully in engaging members and the public through the consultation process.
12.1 In terms of planning conditions, Harrow Council will include conditions concerning the following issues:
• Affordable housing provision; • Sustainable design features; • Landscape, ecology and woodland management plan; • Schedule of landscape maintenance and maintenance of existing habitats (perhaps tied into a Section 106 agreement); and • Management and Maintenance Plans for key buildings and the overall site (perhaps tied into a Section 106 agreement).
12.2 Planning obligations will be sought in accordance with Harrow Council’s adopted planning policy.
12.3 Furthermore contributions will also be sought in the form of planning obligation or section 106 agreement to secure features including:
• Monies to secure a museum facility on the site in relation to the Battle of Britain based on a clear and sustainable business plan ; • Removal of buildings to improve the setting of the listed building and surrounding landscape; • New footpath links as illustrated on the Future use and Development of Bentley Priory plan; • Arrangements for public access to open space within the site, where this can be provided; • Landscape improvements to include: • Thinning of selected planting to the south of the Priory.
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• Reinstatement of parkland to the north of the Priory on area highlighted for nature conservation enhancement. • Installation of a planting screen to the south of area 2. • Area of nature conservation enhancement on the command bunker; • New tree and shrub planting; • Woodland planting and management; • Management of habitats; • Interpretation panels; • Transport improvements; • Affordable housing provision;
(Please note the above mentioned list regarding planning obligation or section 106 requirements is indicative not exhaustive)
12. 4 A Listed Building Consent application or applications will be required for any alterations to the listed building that would affect its special character. Detailed survey work and proposal drawings will be needed to fully understand the impact of any alteration works to the listed building.
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