SPRING 2007 Published for the Brick BRICK Development Association Bulletin

WHY BRICK IS BEAUTIFUL Alan Short on the joy of form and feeling Thermal mass matters: how brick answers the sustainability question Plus: The Ark at Bukharra, UCL’s Slavonic School; Headlands House HERO A W Photo WillPryce ©Thames&Hudson Ltd.,London.From Brick: published byThamesandHudson£39.95 James W.P.Campbell andWillPryce, Brick aWorld History by The ArkatBukharra, Uzbekistan orld History by JamesW. P. Campbell,Thames &Hudson’ A sumptuous reminder The sumptuousness of the Ark at LEADER Bukhara in Uzbekistan is a telling reminder that brick has been around for a long time. Down the course of history the material has responded successfully to the many challenges posed by designers and builders. But recently the rate of change has increased dramatically and the challenges have come thick and fast. The manufacturing process has developed in response to environmental legislation and is regularly out-performing the targets for energy consumption and emissions set by the Government. The demands of the marketplace have meant that manufacturers have devised new products and processes not only to improve site performance but also to ensure that there are techniques applicable to off-site construction. Overarching this activity are the requirements of ‘sustainability’. A few years ago this was a subject for the specialists – now it permeates every activity. The publication of a Code for Sustainable Homes is a good moment to reflect on the relevance of brick to modern construction and that is what this edition of the Bulletin seeks to do. Michael Driver, director Brick Development Association

Cover photograph: Steve Speller

03 David Kirkland and Associates Headlands House SUSTAINABILITY Edmund Sumner

This low-energy house in south social and communal hub of the home. bricks and roof tiles blend well with Hertfordshire is a good example of The skilled local workforce enabled the surrounding buildings. sustainable design. The building is architect to use brick to resolve complex The house has a high thermal mass, designed to take advantage of the views forms not possible or cost prohibitive with complemented by passive solar design and from the site and to answer the client’s brief other types of construction. a ground source heat exchange system that that the fireplace be sited centrally as the The colour and texture of the handmade uses under-floor distribution.

Wright and Wright Women’s library The durability and longevity of a library. The durability of brick and brick structure is well ease with which it can be altered demonstrated by this building, as allows this structure to be

SUSTAINABILITY is the use of thermal mass to recycled and ready to serve for at provide a stable environment in least another 150 years. which to house a precious and The new build is finished in valuable collection. brick externally and internally as Sandy Wright of Wright and cladding to a concrete core. The Wright describes how the thermal mass of this structure building has been ‘stitched into stabilises the temperature within the very fabric of the city to the building and protects the harmonise it with its archive material. As a result the surroundings’. The cue is taken building is naturally ventilated from the blackened brick façade with energy consumption some of the 1846 washhouse, now 80% less than that of an air-

reborn as the entrance to the conditioned equivalent. Cook Peter Photographer Arcaid/Alamy.

04 hours over the last two decades unravelling William Butterfield’s syncopated jazz bonding patterns, most particularly at Keble and All Saints, Margaret Street. Now we wholly understand why one would embrace, with vigour, constructional polychromy to communicate this animation of the actual physical stuff of the building. Emotional intensity of this order is not generated by enamelled steel panels. Calcium silicate brick is peculiarly expressive in this type of work; one could, until recently, evoke the beautiful, and anything but ‘unadorned’, interiors of Hendrik Petrus Berlage’s Amsterdam Beurs, in cinammons, buffs, gingers, dead whites, silver greys and even pale greens. What a scandal that the lazy disclaimers word- processed into insurers’ documentation have all but killed this industry. Here is a fundamentally communicative architecture, ingeniously interconnecting strings of simple rectangular prisms, themselves constructed from very small rectangular prisms, seen at a dazzlingly high level of resolution in the apparently casual but subtly disciplined house forms of Shaw and his contemporaries. But above all, despite our best endeavours, we marvel at Frank Furness’s wildly, violently expressive library at the University of Pennsylvania, a completely Alan Short original conception crashed together from indistinct, inky illustrations in ‘The Builder’ and other long out-of-date European publications; he wasn’t much of a traveller,

OPINION Concept of empathy thank goodness, or he wouldn’t have achieved his shocking new synthesis. Buildings in the future will be different, and ‘empathy’ as a concept Here the bricks become the red hot might just help in the invention of a new and desperately needed molten medium for the transmission of Furness’s extraordinarily original and sustainable and humane architecture periodically evil spirit; he swore continuously. In his library, for which the While many architects still seek the the requirement for 10% on-site renewable drawn elevations are barely believable in revalidation of the super-lightweight energy generation are almost laughable. The their deliberate chaos, red sandstone is used translucent box – in the faint hope of real intent of this legislation is to provoke to clamp the expressive pressures developing miraculous new glasses which won’t dramatic order-of-magnitude reductions in in the sizzling brick panels. haemorrhage energy – others are attempting energy demand through judicious design. In the end the lone designer sits a recovery of authentic masonry architecture. The legislators don’t have much of an idea of confronting a blank sheet, anxious to invent The environmental benefits of thermally what this new architecture is going to be like. some kind of architectural prose, even poetry, massive construction are generally known, That is up to us. The incorporation of brick and no amount of scholarly contextualising but I write here to commend the power and masonry construction as a fundamental is going to help. Why is the idea of brick intensity of expression available through the driver is certainly an interesting starting masonry such a potent companion in this piling up of masonry units, the finest grained position to adopt. lonely task? Why does it invoke such of all being brick. Should ambitious architects be afraid? No. ‘empathy’, or ‘Einfuhlung’, the human Perhaps there is, among a particular If one rejects the long discredited idea of an response Worringer, another practice generation of architects, a fear of an architectural ‘progress’, the predetermined favourite, proposed to explain the direct unwelcome environmental determinism revelation of better ideas invalidating their connection between form and feeling in manifested through banal, ‘passive solar’ predecessors, and substitutes an iterative architecture. form-making in the hairy, grainy natural continuum of experimentation and Perhaps he was less original than we materials of pre-history. However, with the refinement within the greater continuum of thought, as Jarzombek has revealed, but built environment contributing some 45% of human culture, a reservoir of design nonetheless ‘empathy’ as a concept might the energy consumption of a Western strategies becomes available. Brick masonry just help in the invention of this new and economy, I can confidently predict that can be vastly more meaningful than the desperately needed sustainable and humane buildings in the future will be different. rolling out of civic-scaled planes of architecture, an architecture which might Current calculations of the potential unrelieved stretcher bond. turn out to be more familiar than might be impact of photovoltaics and other devices on Unwisely perhaps, we have spent many expected. 05 Michael Driver Sustainability in the brick industry SUSTAINABILITY

Sustainability is a current buzz word that has Objective Reducing the impact of atmospheric emissions from the production process transformed attitudes in the construction KPI: CO2 emission per square metre of brickwork industry. Those who would once only pay lip service to the concept are now seriously Tonnes CO2 / sq metre / annum examining their products and processes to 2000 0.000235 identify, evaluate and improve their 2005 0.000232 sustainability credentials. The brick industry was one of the founder The measure reflects the contribution of CO2 emissions per square metre of brickwork per annum members of the Government’s Pioneers attributable to brick assuming an average expected service life of 120 years. The CO2 emissions com- Group and it was one of the first UK prise direct emissions from energy and process as reported under the EU Emissions Trading Scheme. industrial sectors to publish its sustainability policy. This was based on a Government Objective Reducing energy consumed through improved energy efficiency strategy designed to be applicable to all KPI: Specific energy consumption per tonne of output industrial sectors, holistic rather than simply being concerned with energy consumption Output (tonnes) Energy consumed (KWh) SEC in manufacture and construction. Its 2001 6,539,688 51,000,130,531 779.9 underlying principle is that sustainability is 2005 6,357,704 4,810,757,299 756.7 about the responsible use of resources. Alternatively, seen from the Brundtland Energy comprises a major cost for the industry. Consequently there is ongoing commitment to Commission’s angle, it concerns ‘meeting the improving efficiency. In addition the industry has participated in Climate Change Agreements since needs of the present without compromising 2001 and is subject to the EU Emissions Trading Scheme. the ability of future generations to meet their own needs’. Objective Minimising virgin raw material (clay) consumption Underlying these two definitions are four KPI: Proportion of raw materials derived from sources other than clay extraction key points that lie at the heart of the Government’s thinking on sustainability: Research undertaken recently by CERAM Building Technology has established that: 1 Social progress that recognises the needs 8.3% of the industry's raw materials are derived from sources other than the primary extraction of everyone of clay 2 Effective protection of the environment This equates to 643,000 tonnes of materials 3 Prudent use of resources The industry has very close to 100% internally generated process waste recovery and recycling 4 Maintenance of high and stable levels of economic growth and employment It is intended that this measure will be continued in future years. Having identified the areas of possible improvement the brick industry took its first M steps in what has become a dynamic and ongoing process. A set of key performance indicators (KPIs) were selected to allow the impact of clay extraction sites. Exhausted highlighting the consumption of a industry to predict, measure and review use pits are being restored to beneficial particular resource without taking into of resources and chart progress towards community use, incorporating tree account the fact that brick has been shown defined aims. These KPIs are evaluated and planting, imaginative landscaping, and the to last hundreds and sometimes even reviewed annually. creation of lakes for leisure or nature thousands of years. conservation programmes. As part of its Social progress energy commitment, industry will reduce Economic growth and employment The brick industry’s objectives include energy consumption by more than 10% by The industry employs 5,500 people over improving the occupational health and 2010 under the Government’s climate nearly 90 manufacturing sites. Maintaining safety of its employees, introducing relevant, change levy. Progress reports indicate this high and stable levels of economic growth useful vocational training to improve target is likely to be exceeded. and employment is therefore crucial. This employee development, and maintaining will be achieved by maintaining and and further developing liaison with, and Prudent use of resources improving profitability to provide for support for, local communities. This latter BDA members recognise the importance of continuing investment and employment; point is particularly important as many measuring and reducing the consumption increasing investment in plant and brickworks are located in rural areas. of natural resources such as the volume of machinery in order to improve treated water and energy use. It is manufacturing efficiency and Protection of the environment important that the resources consumed in environmental performance; and The clay brick industry is working hard to production are evaluated over the whole developing new products to increase minimise the visual and environmental lifecycle of the product. It is pointless added value. 06 Feilden Clegg Bradley The National Trust - Swindon SUSTAINABILITY Denis Gilbert/ VIEW

Three principles guided the design of this building for the National Trust. The building had to be: 1 The most sustainable building possible within budget 2 The best possible working environment 3 The most appropriate contextual response

The trapezoidal plan is capped by saw-tooth roof lights that are used for both north light and for accommodating south-facing photovoltaic panels. The roof creates Short & Associates three gabled elevations that are built in Peter Cook/ VIEW Peter Staffordshire Blue brick. The external walls are 442mm thick with a U-value of School of 0.2 achieved by a 140mm-thick internal concrete blockwork (rendered internally to capitalise on thermal Slavonic studies mass), a 200mm cavity containing

SUSTAINABILITY 150mm of high-performance insulation and the 102mm-thick external facing The building created to house the School of the perimeter stacks and roof-mounted brickwork laid in lime mortar. Slavonic Studies at University College, chimneys. Internally, the exposed thermal mass London, is the latest of Short Associates The brickwork of the façade consists of an in the walls and fair-faced concrete designs to use natural ventilation for a large outer 215mm-thick solid brick wall tied soffits help to mitigate solar gains building. It is the first time that passive across a 100mm cavity to an inner 215mm assisted by natural ventilation and night down-draft cooling has been used on a wall that is left fair-faced. The dentilled cooling in summer. The distinctive roof public building in a major city. architrave to the main elevation doubles as cowls promote both stack and wind- The thermal mass of the masonry of the an ingenious exhaust duct. driven ventilation. main elevation and the staircase zone behind The confident detailing of the brickwork The building achieved an ‘excellent’ it allows the stair void to act as a huge shows how, with care and thought, it is BREEAM rating. It provides first-class ventilated cavity. This tempers the building’s possible to use brick to produce an working conditions and sits comfortably internal temperatures working in architecture that is vibrant and dynamic in the context of the Victorian railway conjunction with the central glass atrium while at the same time creating a building sheds of Brunel’s Great Western that rises through the middle of the building, with impeccable sustainability credentials. Railway.

07 Michael Driver Brick and brickwork:

ADAPTABILITY production and use

The current debate on construction has The construction are between 100 and 140 years old, 8% are developed into an argument about the between 80 and 100 years old, 32% are relative merits of different materials and techniques that between 60 and 80 years old and 40% are whether specific methods of construction are involve brick are less than 60 years old. more sustainable than others. The object of the survey was to This debate misses the point; namely that well understood. determine how much maintenance, repair, it is the prime responsibility of everyone in What is less and renewal has been carried out on the the construction industry to create spaces buildings and to draw conclusions on the and places that enhance people’s lives. Unless appreciated is the life expectancy of the structures. The oldest we build houses that are good to live in and value of the structures were solid wall construction with in communities that function well, we will cavity wall introduced in the last 100 years. create a tranche of buildings that people installed cost of The conclusions are that, given sensible don’t respect and therefore seek to destroy. brickwork maintenance and repair, there is no reason You have only to revisit the housing boom of why brick structures shouldn’t be the 1960’s to see what happens when considered to have a life of 500 years and inhabitants are alienated. beyond. Repointing first occurs on average If enhancing people’s lives is the primary after 85 years and by then some of the focus it still must be achieved sustainably, buildings had experienced some repair – that is through a responsible use of resources for example to lintels or the replacement of – be they human, physical, or financial. It is from landfill, or other alternative sources, a few bricks. The message is that if these considerations that reinforce the case have reduced the energy consumed whilst brickwork is well built and maintained it for brick because in brick we have a material developments in flue technology have will continue to do its job efficiently and that is: reduced the emissions. The brick effectively for a long time. Aesthetically pleasing and mellows with component in a square metre of brickwork

age, people feel comfortable living with it produces 27kg CO2 by the time it is Recycling Durable and long-lasting, requiring delivered to site. This equates to 0.000232 There are many reasons why buildings are minimal maintenance tonnes/per sq metre/per annum over a life demolished. However, it is unlikely to be Well understood yet capable of further span of a 120 years. To put this into context that the brickwork is in such poor condition development recent studies suggest that at 60 years the that it is not worth keeping. Brick buildings Able to be used in conjunction with other ratio of embodied energy of construction to are often recycled, fulfilling functions materials and all construction systems the operational energy in a building is 1:10. different to those for which they were Easy to adapt to accommodate the changes designed. Their basic construction makes in the function of the building Installed cost of brickwork this a good option and it is certainly Fireproof, insect and water resistant The construction techniques that involve sustainable. Sustainable because it is created as a result brick are well understood. What is less However, if there is no option other than of a responsible attitude to human, natural appreciated is the value of the installed cost to demolish it is still possible to benefit and physical resources of brickwork. The current price for a square from a brick building. There is a thriving Good value whether you are considering metre laid of facing brickwork is around market in reclaimed bricks and while a initial cost or lifecycle cost £35. The brick component in this equation specifier needs to be careful to check the is around £15 to £18 per square metre. quality of the reclaims there are many Embodied energy examples where the new build has Brick production at its most fundamental is a Lifespan of clay brickwork walling been successful. combination of earth, water and fire. Clay is In the Green Guide to Specification, Modern bricks have carefully defined dug, moistened and formed, then dried and (Howard et al 1998) it states: ‘Brick properties. In future this will take the guess fired. However, modern production is a construction may indeed last many work out of the use of reclaimed bricks and, sophisticated version of the fundamental hundreds of years.’ While in the PhD thesis along with the use of mortars that can be process. Clay is usually dug near the factory, Whole Life Performance of Clay Masonry cleaned off the brick, will maintain the prepared on site then formed by throwing, Brickwork written by Adrian Brown of popularity of the material. pressing or extrusion before being dried in Leeds Metropolitan University there is a If reclaiming the brick is not an option chambers warmed by heat extracted from the record of a survey of 860 domestic and low- there are many uses for crushed brick. kilns. Waste clay is recovered and returned to rise brick built properties across the North Shale tennis courts, green roofs, paths and the process. Fuel-efficient kilns, generally of England. Twenty two per cent of the general construction hardcore means that fired by gas but also by methane recovered properties are more than 140 years old, 12% there will be very little disposed to landfill. 08 Survey The chronicles of MARSS: alternative, recycled and secondary resources SUSTAINABILITY

Organics

Industrial minerals

Ash

Hydrocarbon

Water

Minerals

0 102030405060

One measure of sustainability is the amount accounting for more than 85% of the Recovered water accounts for 33% of material from alternative, recycled and clay used in the manufacture of of all the water used in the brickmaking secondary sources (MARSS) that is included clay bricks. process. in a product. In the case of clay bricks, these The survey identified 28 different This is an important contribution to materials replace the primary clay thereby MARSS materials divided into six major sustainability because recovery saves the conserving existing stocks. groups – their use is recorded above. use of treated water. It should go without In 2006 CERAM was commissioned by Manufacturers were asked to identify the saying that the industry is determined to the industry to carry out a survey of the use benefits and reasons for the use of MARSS improve this figure year on year. of MARSS in brickmaking. materials. Non-primary clay (generally fire- While individual factories make more or The survey covered 51 factories using clay) accounted for nearly 44% of MARSS less use of MARSS materials, the average MARSS materials representing 67% of the material usage, bulking additives 15% and percentage addition rate in a brick is production sites in the UK and colourants 9%. 11.89%.

Cullen Carter Hill Papplewick pumping station Ravenshead, Notts

SUSTAINABILITY The pumping station at condition but repair and Papplewick is a rare example of restoration was needed to the a group of buildings that are general fabric. both listed and a scheduled The brickwork and terracotta ancient monument. Erected plasters and mouldings were between 1882 and 1885 by Ogle satisfactory and it was only Tarbotton for Nottingham where the face of a brick was Corporation Water Department, blown that new brickwork the complex is a fusion of was required. architecture, engineering, art Bricks were specially made to and landscape. Papplewick was match the original, together with on the English Heritage list of mouldings for the pumping Buildings at Risk, but the station, boiler house, chimney, Papplewick Trustees and and superintendent’s house. Association obtained a BIFFA This fine group of buildings will award to carry out repairs led by become a valuable resource for Cullen Carter Hill. both the public and scholars. A structural assessment of the They are ample evidence of the buildings showed that after 120 durability and longevity of brick years the structural components structures – key components of the building were in good when considering sustainability.

09 Long and Kentish in association with Colin St John Wilson and Associates ADAPTABILITY

Pallant House Gallery: Chichester Arcaid/Alamy. Photographer Ben Luxmore Photographer Arcaid/Alamy.

Pallant House, originally built in the 17th art. The house was renovated and extended It’s stands as a clear demonstration of the century for a Chichester Merchant now has through 2004-6 by architcet Long and adaptability of brick structures and how another life as the home for the Pallant Kentish to accept the collection of Colin skilful use of the material gives a common House Collection of early twentieth century St John Wilson. thread to the house and its extension.

James Cubitt Digswell Viaduct: Hertforshire 1848-1850

Engineer James Cubitt (1811-1872)

LONGEVITY and Contractor Thomas Brassey (1805-1870) were responsible for the wonderful Digswell Viaduct which carried the twin tracks of the Great Northern Railway across the Mimram Valley. The viaduct is a whopping 470m long. The 40 arches each span 9.1m and are up to 30m high.Thirteen million bricks were used in its construction. This structure is still carrying the East Cost Main-line and other traffic and is a prime example of the durability and longevity of brick. Arcaid/Alamy photographer Will Pryce photographer Arcaid/Alamy

10 St Pancras challenge AVAILABILITY &

sideways. This gave a frog on both sides. The moulds were deeper than normal and

AFFORDABILITY turning out the clay was difficult because of the mould shape and the position of the finished face. Brickmakers at Charnwood proved equal to the challenge and maintained a steady supply of facing bricks in accordance with the construction programme. Bulmer Brick was successful in quoting for the red rubbers in conjunction with Bulmer Brick Cutting. While manufacturing red rubbers is well understood, the production of a large quantity of cut bricks to very fine tolerances needed some lateral thinking. Bricks are cut to templates and, rather than employ conventional pattern makers, Bulmer approached a laser cutting company that normally works in the packaging industry to laser cut 15mm birch ply templates from CAD drawings. In order to achieve cuts that tapered 0.5mm over 115mm and 1mm over 229mm, Bulmer redesigned the standard masonry cutting saw bench so that it was able to maintain accuracy over an extended period. Finally, the shaped pieces had to be The supply chain delivered to site to allow the arches to be

Will Pryce constructed with confidence. This was achieved by devising a system of purpose- When St Pancras was built in the early 1870s manufactured. Bulmer Brick Cutting proved made packing trays containing bricks packed it was the largest rubbed and gauged equal to the task of cutting and supplying in the correct sequence for laying. brickwork project in the world, consuming 22,000 pieces and Irvine Whitlock’s The bricklayers of Irvine Whitlock vast quantities of facing bricks and all of the bricklayers demonstrated that their skill relished the opportunity to demonstrate UK stock of washed rubbing blocks. When levels were at least the equal of their their skill laying the facing bricks in a lime the west elevation was to be rebuilt as part of Victorian counterparts. When the Victorian mortar of 5mm thickness and the rubbed the works for the Channel Tunnel Terminus facing bricks from St Pancras were analysed it bricks and stone in fine 2mm joints using a there were people who said the British was clear that the clay had come from pure, sand-free lime putty. The evidence of construction industry no longer had the Leicestershire. However, the shape of the their skill will be on view for many years. necessary craft skills to handle difficult large- brick and the finish to the face required a The significance of this project is that each scale projects with intricate brickwork reappraisal of current hand-throwing component of the supply chain showed the detailing. techniques. Instead of the face being the ability to solve problems and then deliver. It However, the brick industry, in the shape result of clay meeting the mould, the face of should inspire other designers to design in of Charnwood Forest Brick and Bulmer Brick the St Pancras brick was the open side of the brick confident that the industry is able to & Tile, showed the materials could be mould, meaning that the bricks were thrown respond to any challenge. Bricklayer Shortage There is a perception that there Whitlock and Chairman of the hence they will find it hard to layers in the UK. If each brick- is a shortage of bricklayers in Association of Brickwork Con- recruit. But if the tradesmen are layer lays 500 bricks per day for the UK and this is always cited tractors, and he will tell you treated fairly, Geoff will tell you 5 days per week the output of as a reason for using alternative there is no shortage of skilled that there is no evidence of a the UK brick industry will be laid methods of construction. How- tradesmen. shortage. within 10 weeks. This leaves ever, this perception is wrong. The problem might be that A simple calculation supports plenty of time for bricklayers to Speak to Geoff Irvine, Chairman some contractors do not value Geoff's assertion. The CITB gives lay blocks and do all the other of brickwork contractors Irvine the services of bricklayers, 117,500 as the number of brick- things they do.

11 Products and process

Brick manufacturers are aware 11 that they have to expand their product line beyond the traditional brick. This has resulted in a number of new products that can be grouped under three headings: The Unit, The Component and The Process.

02

01 07

Unit Component

01 Angle brick 05 Pre-assembled brickwork A neat way of producing any angle in a run Pre-assembled feature brickwork details of brickwork. for incorporation into standard masonry.

PRODUCTS Illustrated are bulls-eye and stack bond. 02 Spiral brick Also available basket-weave, quoins, A single brick that produces a spiral barley dentils, bonding course and solider course twist column. polychromatic brickwork.

03 Tile brick 06 Prefabricated brickwork An extruded clay unit that replicates tile Off-site assembly of complete hanging. Laid by bricklayers, it allows ‘tile- components, such as columns at the hanging’ to be incorporated into a façade Inland Revenue Building, Nottingham, and without a change of trades. brickwork at The Grove, Watford.

04 Different formats A series of large format clay blocks complement the different sizes that manufacturers now offer.

12 06 08 03

05 09

10

04

Process

07 Corium 10 Traditional Plus A system that provides a mechanical fixing A single brick external wall using a for a clay tile to a plastisol-coated metal 140mm-wide brick. Intermediate floors tray. A variety of tile shapes is available. and restraint ties are located in the brick. The insulation is placed on the internal 08 Thin joint brickwork face of the external wall. A modified sand and cement mortar that glues brickwork together. The mortar is 11 Earth bricks mixed and pumped through a hand-held A range of unfired clay bricks and blocks nozzle. The joints are 3mm-4mm and intended for internal use. Excellent there is no mortar in evidence, hence the sustainability credentials, low energy effect of the clay is intense. Applicable for input, low waste, fully recyclable. They give both on-site and prefabricated brickwork. a building thermal mass, inhibit condensation and regulate the relative 09 Wonderwall humidity of the atmosphere. A system that glues brick slips on to an insulated backing sheet.

13 Dr Ali Arasteh Why masonry mass could be critical THERMAL MASS

There is now an overwhelming body of evidence, documented in the recent Stern Review, for climate change caused by greenhouse gases. And The Met Office data continues to forecast a warmer climate through the latter part of the century. As a result it is quite likely that homes of the future could require mechanical cooling in order to maintain a comfortable environment. However, the impact of release of the resulting CO2 into the atmosphere (together with concerns over the security of the energy supplies) have given rise to a different appraisal of performance of building components and fabrics.

Overheating may be avoided by: Improved ventilation through suitable ventilation stacks, ducting and natural convection Solar shading through correct orientation of building, blinds and shutters Active use of thermal mass

The mechanism by which 'heavyweight' building structures absorb and release heat in a way which is beneficial to the occupants is shown in figure1 below. As the outside temperature rises heat is absorbed by thermal mass during the day and then slowly released during the night.

Heavyweight masonry buildings: Absorb heat during daytime Release heat during night time The 'lag' illustrated helps to stabilize indoor temperatures In contrast insulated lightweight structures tend to absorb and dissipate heat much more quickly. Figure 1: Illustration of thermal mass benefit of ‘heavyweight’ structures Historical precedence Passive Solar Design or PSD utilizes an 30°C efficient combination of thermal mass, natural ventilation and solar shading and has 2 been successfully used in the Middle East for 1 centuries. The sketch, top left, shows the principles of how wind is used as the source of clean and natural ventilation in a dwelling.

15°C A tower 'catches' the wind and directs it to the interior of the building; shades and shutters are used to moderate the effects of Day Night Day outside temperature on the indoor environment and complement the 1 Heat absorbed during the day Internal temperature sustainable architecture of a clay 2 Heat released during the night External temperature masonry building. 14 Dr Ali Arasteh The structural role of brick

STRUCTURE Figure 1: Vertical loading only

=ORBut 37% weaker

102.5 100 135 100 Brickwork Tied cavity wall Single leaf Single leaf Insulation Both require rainscreen cladding + insulation Blockwork

Figure 2: Lateral loading only

=ORBut 70% weaker

102.5 100 150 100 Brickwork, 7

Brick has been a reliable construction The larger number of joints offers a more In a typical brick and block cavity wall material for centuries – and with good ‘articulated’ form and reduces strain panel, 2.5m high x 5m long in simple reason. concentration. bending along the bed-joints: It is user friendly, relatively easy to Spacing of movement joints in clay 150mm thick blockwork is needed to manufacture and offers unparalleled masonry is about twice that in cementitous compensate for omitting brickwork, again versatility in use. masonry. with render/rainscreen and insulation. It is compatible with many different forms And in case of orthogonal bending of the of construction. Brickwork contributes to strength and panel: It offers a durable attractive envelope with enhances structural performance. In a Some 70% of the bending strength is proven performance. ‘standard’ cavity wall construction of 100mm provided by the brickwork with further It makes a significant contribution as a inner leaf blockwork and 102.5mm outer leaf enhancement if the self-weight is taken structural component. brickwork and a typical storey height of 2.5m into account. It has excellent flood resistance/resilience omitting the brickwork has the following Lower orthogonal ratio of brickwork properties; a CIRIA report (to be consequences: results in a greater two-way action of the published) places Engineering Bricks at A minimum of 135mm-thick blockwork is panel. the top of its recommended materials of needed to achieve the same vertical The enhancement by the brickwork to construction for dwellings. loadbearing capacity. laterally loaded masonry panels applies to For the same thickness blockwork the wall load-bearing masonry as well as masonry It is this latter point that is least is some 37% weaker. infill walls to frame structures. understood and is highlighted here. A single leaf wall requires insulation and It is therefore clear that brickwork is not Brickwork, made with standard UK bricks, render or some form of rainscreen – both just a pretty face and when used as so-called can accommodate movement better than of which increase the overall thickness cladding it makes a significant structural other forms of masonry: without any structural benefits. contribution. 15 Michael Driver BDA: promoting the best of brick

The Brick Development Association (BDA) designed to promote excellence in the specifiers and members of the public can was established to promote the best possible architectural, structural and landscape access a comprehensive resource on the BACKGROUND uses of clay brickwork and clay paving. This applications of brickwork. These are practical, technical and aesthetic aspects of includes maintaining and disseminating the spearheaded by the Brick Bulletin, the brickwork either by telephone, the website traditions that have made brick one of the annual Brick Awards – which have become (www.brick.org.uk) or through the extensive great materials of construction. But it also one of the most prestigious events in the range of BDA publications. BDA staff work includes supporting ongoing research into construction industry calender – and by BDA on the drafting of technical publications, new uses for brickwork that will ensure its technical staff, who lecture to schools of codes and standards. They represented the use well into the third millennium. Helping architecture and engineering, as well as at industry on the committees that formulated the BDA achieve these goals are its members CPD events. the new harmonised European standards and who together account for over 98% of clay The BDA provides comprehensive advice are currently involved in revisions of the brick manufacture in the UK and Ireland. and information on every aspect of brick technical literature to take account of the A wide range of BDA activities are construction. Architects, engineers, new standards.

Member companies

Baggeridge Brick plc Carlton Brick H G Matthews Phoenix Brick Company Ltd Fir Street, Sedgley, Dudley Grimethorpe, Near Barnsley The Brickworks The Brickworks, Campbell Drive West Midlands DY3 4AA South Yorkshire S72 7BG Bellingdon, Chesham Barrow Hill, Chesterfield S43 2PR Tel: 01902 880 555 T 01226 711 521 Bucks HP5 2UR T 01246 233 223 Fax: 01902 880 432 F 01226 780 417 T 01494 758 212 F 01246 230 777 email. [email protected] Sales Line: 01226 715 000 F 01494 758 077 E [email protected] www.baggeridge.co.uk. W www.bricksfromphoenix.co.uk Sales office: Charnwood Forest Brick Ltd Ibstock Brick Ltd T 01902 880 666 Old Station Close, Shepshed Ibstock, Leicestershire, LE67 6HS Wm. C Reade of Aldeburgh Ltd F 01902 880 432 Nr Loughborough T 01530 261 999 Aldeburgh Brickworks E [email protected] Leicestershire LE12 9NJ F 01530 257 457 70-72 High Street, Aldeburgh London consultancy: T 01509 503 203 www.ibstock.co.uk Suffolk IP15 5AF T 020 7236 6222 F 01509 507 566 Scotland: T 01728 452 982 F 020 7248 6363 E [email protected] Glasgow T: 0870 903 4001 F 01728 454 957 Rudgwick sales office: W www.michelmersh.com North West: E [email protected] T 01403 822 212 Parkhouse T: 0870 903 4007 F 01403 823 357 Coleford Brick & Tile North East: Swarland Brick Co Ltd The Royal Forest of Dean Throckley T: 0870 903 4004 Thrunton Blockleys Brick Ltd Brickworks Cinderford, Eastern: Whittingham Sommerfeld Road Gloucestershire GL14 3JJ Leicester T: 0870 903 4008 Alnwick Trench Lock T 01594 822 160 West Midlands: Northumberland NE66 4SD Telford, Shropshire TF1 4RY F 01594 826 655 Lodge Lane T: 0870 903 4006 T 01665 574 229 T 01952 251 933 E [email protected] South West: F 01665 574 400 F 01952 265 377 W www.colefordbrick.co.uk Cattybrook T: 0870 903 4010 E [email protected] E [email protected] South East: W www.michelmersh.com Dunton Brothers Laybrook T: 0870 903 4012 Tyrone Brick Ltd Meadhams Farm Brickworks 48 Coalisland Road, Dungannon Bovingdon Brickworks Ltd Blackwell Hall Lane Kingscourt Brick Northern Ireland Pudds Cross, Bovingdon, Near Hemel Ley Hill, Chesham Kingscourt,Drumsgill BT71 6LA Hempstead, Hertfordshire HP3 0NW Bucks HP5 1TN County Cavan, Ireland T 02887 723 421 T 01442 833 176 T 01494 772 111 T +353 (0)42 9667 317 F 02887 727 193 F 01442 834 539 F 01494 791 255 F +353 (0)42 9667 206 W www.tyrone-brick.com E [email protected] E [email protected] E [email protected] W www.bovingdonbricks.co.uk W www.michelmersh.com W www.laganbrick.com The York Handmade Brick Co Ltd Forest Lane, Alne, York YO61 1TU Broadmoor Brickworks Ltd Errol Brick Michelmersh Brick & Tile Co Ltd T 01347 838 881 Whimsey, Cinderford Inchoonans Road Hillview Road F 01347 838 885 Gloucester GL14 3JA Errol, Perth PH2 7RB Michelmersh, Romsey SO51 0NN E [email protected] T 01594 822255 T 01821 642 653 T 01794 368 506 W www.yorkhandmade.co.uk F 01594 826782 F 01821 642 427 F 01794 368 845 E [email protected] E [email protected] E [email protected] W H Collier W www.michelmersh.com Church Lane, Marks Tey, Bulmer Brick & Tile Co Ltd Freshfield Lane Brickworks Limited Colchester, Essex CO6 1LN Brickfields Danehill, Haywards Heath Normanton Brick Co Ltd T 01206 210 301 Bulmer, Sudbury Sussex RH17 7HH Altofts Brickworks, F 01206 212 540 Suffolk CO10 7EF T 01825 790 350 Greenfield Road, Normanton E [email protected] T 01787 269 232 F 01825 790 779 West Yorkshire WF6 2DJ F 01787 269 040 E [email protected] www.flb.uk.com T 01924 892 142 / 01924 895 863 Wienerberger Ltd E [email protected] F 01924 223 455 Wienerberger House, Brooks Drive, Hammill Brick Limited Cheadle Royal Business Park Caradale Traditional Brick Ltd Woodnesborough Northcot Brick Limited Cheadle, Cheshire SK8 3SA Etna Works Sandwich Blockley, Near Moreton-in-Marsh, T 0161 491 8200 Lower Bathville, Armadale Kent CT13 OEJ Gloucestershire GL56 9LH F 0161 491 1270 West Lothian T 01304 617 613 T 01386 700 551 E [email protected] EH48 2LZ F 01304 611 036 F 01386 700 852 W www.wienerberger.co.uk T 01501 730 671 E [email protected] F 01501 732 991 Hanson Building Products W www.northcotbrick.co.uk The Brick Development Association Ltd. E [email protected] Stewartby, Bedford MK43 9LZ Woodside House, W www.caradale.co.uk London, Butterley, Desimpel, Ormonde Brick Ltd Winkfield Red Bank, Wilnecote Range. Castlecomber Windsor, Berkshire SL4 2DX T 0870 609 7092 County Kilkenny, Ireland T 01344 885 651 F 01234 762 040 T +353 (0)56 44 41323 F 01344 890 129 E [email protected] F +353 (0)56 44 41314 E [email protected] W www.hansonbrick.com E [email protected] W www.brick.org.uk W www.ormondebrick.ie