Institute of Historic Building Conservation No 99 May 2007 Rebuilding Bath’s spa
ii C O N T E X T 9 9 : M A Y 2 0 0 7 Farrow & Ball produce traditional wallpaper and more paint finishes than any other manufacturer. From Distempers and Dead Flat Oil for interior use, to Limewash and traditional Real Lead Paint for exteriors, you need look no further than Farrow & Ball. Contact us for a complimentary colour card and brochure. For a showroom or stockist near you call us on +44(0)1202 876141 www.farrow-ball.com Image © National Maritime Museum Mahogany Dead Flat Oil & Hague Blue® Estate® Emulsion
C O N T E X T 9 9 : M A Y 2 0 0 7 Context Cover: Spa buildings in the heart of Bath (Photo: Jonathan Taylor) See p21. The wisdom of footballers’ wives Editorial Briefing 2 Out of Context 4 In memory of… 4 Periodically 5 TheWriter’s Voice 6 Supporting Columns Brian Morton 7 Cosmopolitans, style hounds and traditionals Keith Parsons 11 Embodied energy: new build v refurbishment David Drewe 13 Finding out about embodied energy Devon DeCelles 14 English Heritage focuses on energy ChrisWood 17 Rebuilding the spa in Bath Peter Carey 21 Managing the waterways heritage Nigel Crowe 26 Serious settlement and a light touch Ian Hume 29 English Heritage’s research role Colum Giles 31 IHBC response 34 Notes from the chair 37 Vox pop 38 Book reviews 39 Products and services 41 Manchester United footballer Michael Carrick has decided to demolish a 1960s house in Cheshire’s footballers’ belt (the stockbrokers moved from the area long ago) and build a £3.5 million, neoGeorgian replacement. His team-mates Wayne Rooney, Gary Neville and Ryan Giggs have already done the same. Before deciding to take the demolishand-rebuild option, the footballing four will have considered the issue of embodied energy. Building the houses and providing their materials takes a great deal of energy, contributing to global warming and – among other things – the consequent very real danger of Old Trafford’s hallowed turf shrivelling up. ‘On the other hand,’ they will have mused, ‘if the new house is more energy efficient than the demolished one, over its lifetime it may save energy.’ Their wives, belying their reputations for lacking intellectual curiosity, may have butted in at this point. ‘Ah yes, Michael/Wayne/Gary/Ryan,’ they probably will have said, ‘and we must consider how the equation would be affected if we take into account the possibility of recycling, recovering or reusing the materials of the old house. We need also to consider the energy required to maintain the house’s fabric and equipment – including the indoor swimming pool on which we have set our hearts – over its lifetime.’ Unlike many in the conservation field, the footballers will not be concerned with establishing how much energy is embodied in the building that is to be demolished. That energy has been used anyway and – except insofar as recycling, recovering or reusing are possible – is irrecoverable. They will be familiar with the Building Research Establishment’s calculation that the embodied energy in a typical Victorian terrace house is equivalent to the amount of petrol required to send a car around the earth five times or halfway to the moon.They will know that the BRE’s statistic is completely irrelevant. And anyway, as any footballer knows, having driven halfway to the moon you would then have to drive back, using the same amount of energy again. Not everyone is as enlightened about such matters as we imagine Manchester United’s stars to be. That is why in this issue we are following our features on energy-efficient conservation in the previous one (Context 98, March 2007) with some guidance on where to find further information on the subject. For those who are too busy to read the latest research, we can summarise: particularly in the case of buildings dating from before the second world war, conservation and reuse tends to be the more environmentally responsible option. The Institute of historic building conservation www.ihbc.org.uk Registered as a Charity Number 1061593. Company Limited by Guarantee. Registered in England Number 3333780. Registered Office: 3 Stafford Road,TunbridgeWells, Kent TN2 4QZ. IHBC Officers President David Lovie email president@ihbc.org.uk Chairman JohnYates email chairman@ihbc.org.uk Vice Chair Dave Chetwyn email vcpolicy@ihbc.org.uk Secretary Richard Morrice email secretary@ihbc.org.uk Treasurer Michael Knights email treasurer@ihbc.org.uk Membership Secretary Mike Lea email membership@ihbc.org.uk Consultations Secretary vacant email consultations@ihbc.org.uk Education Secretary John Preston email education@ihbc.org.uk Publicity Secretary vacant email publicity@ihbc.org.uk Law & Practice Coordinator vacant email law@ihbc.org.uk Director Seán O’Reilly email director@ihbc.org.uk Projects Officer Fiona Newton email projects@ihbc.org.uk Membership Services Officer Devon DeCelles email membershipservices@ihbc.org.uk IHBC Committee Chairs Policy Dave Chetwyn email vcpolicy@ihbc.org.uk Membership & Ethics Mike Lea email membership@ihbc.org.uk Finance & Resources Richard Morrice email resources@ihbc.org.uk Education John Preston email education@ihbc.org.uk Communications & Outreach Mike Brown email communications@ihbc.org.uk Branch Officers North Geoff Underwood Tel 0191 433 3435 NorthWest Graham Arnold Tel 0151 606 2157 Yorkshire Keith Knight Tel 01904 658482 West Midlands Charles Shapcott Tel 020 7973 3660 East Midlands Roy Lewis tel 01332 591175 South Rob Parkinson Tel 01993 861680 SouthWest Ian Lund Tel 01380 724911 East Anglia Pippa Colchester Tel 01245 437337 South East David Kincaid Tel 01227 862185 London David McDonald Tel 020 8881 6724 Scotland Charles Strang Tel 01835 822560 Wales Nathan Blanchard Tel 01285 642428 Northern Ireland Sharon BrownTel 028 9754 3087 Republic of Ireland Bernard DeeTel 00353 1 873 7226 Business Office Jubilee House, High Street, Tisbury, Wiltshire SP3 6HA England Tel 01747 873133 Fax 01747 871718 email admin@ihbc.org.uk
C O N T E X T 9 9 : M A Y 2 0 0 7 Context Briefing Copy deadlines Context is published five times a year, in March, May, July, September and November. Copy deadlines in 2007 are: Issue Deadline July, Issue 100 18 May September, Issue 101 13 July November, Issue 102 14 September Editor Rob Cowan Editorial Coordinator Fiona Newton 21 George Street, Louth, Lincolnshire LN11 9JU Tel 01507 602567 email editorial@ihbc.org.uk Editorial Board Fiona Newton (chair) Susan Brook (treasurer) Nigel Crowe (main features) Peter de Figueiredo (book reviews) Michael Taylor (main features) Cartoons by Rob Cowan Context is distributed to all members of the Institute of Historic Building Conservation. © Institute of Historic Building Conservation 2007 ISSN 0958-2746 Publisher Published for the Institute of Historic Building Conservation by Cathedral Communications Limited, High Street, Tisbury,Wiltshire, England SP3 6HA Tel 01747 871717 Fax 01747 871718 email context@cathcomm.demon.co.uk www.buildingconservation.com Non-member subscriptions to Context Context is available to non-members of the IHBC at an annual subscription rate, including postage, of: United Kingdom £50.00 Elsewhere £75.00 Subscription orders, together with remittances payable to Institute of Historic Building Conservation, should be sent to the IHBC Business Office at Jubilee House, High Street, Tisbury, Wiltshire SP3 6HA. The views expressed in Context are not necessarily held by the IHBC or the publisher. Neither the publisher nor the IHBC shall be under any liability whatsoever in respect of contributed articles. We gratefully acknowledge the support of firms whose advertisements appear throughout this publication.While every effort has been made to ensure that the information contained in this issue of Context is current and correct, neither the IHBC nor the publisher can be held responsible for any errors or omissions which may occur. Voluntary land registration The registration of land is often an issue in conservation matters, particularly in rural areas. Over 40 per cent of England and Wales remains unregistered. Much urban land has been compulsorily registered, because, for example, it has been sold, mortgaged or re-mortgaged. But many rural areas in England and Wales remain unregistered, mainly because the turnover of land ownership is much lower. Registering land with Land Registry means that the state guarantees the owner’s title to their property, giving them better protection. It also means that if and when they come to sell, or they are asked to prove their ownership, they have easy access to their records online. To encourage voluntary registration, Land Registry offers a 25 per cent discount on its usual registration fee. It has also set up a national register development team and local teams for each of its offices to help promote and encourage people to register their land voluntarily, and to guide applicants through the process. Land registration allows landowners to manage their land more effectively, to consolidate complex legal information or historic data about their land, and to help protect their land against encroachment. For further information about voluntary land registration phone 0800 432 0432 or visit www.landregistry.gov.uk. Bodley and Kempe at 100 The Churches Conservation Trust is offering a range of tours and talks to celebrate the work of George Frederick Bodley and Charles Eamer Kempe, two significant figures in Victorian and Edwardian church art, design and decoration (and lifelong friends as well as colleagues), on the centenary of their deaths. The legacy of these two designers can be seen in 12 of the trust’s churches. GF Bodley (1827–1907) was one of the most important architects of the gothic revival movement, whose creative talents and influential patronage shaped late 19th century building design and decoration. He is known for championing the revival of late medieval English architecture and for his rich, stencilled decorative schemes. The studio of CE Kempe (1837–1907) specialised in church decoration and is renowned for its exquisite stained glass. Identifiable by its quirky wheatsheaf motif and distinguished by its sensitive draftsmanship, jewel-like palette and faithful adherence to the traditions of Photos: Steven Cole ©The Churches Conservation Trust
C O N T E X T 9 9 : M A Y 2 0 0 7 Wales branch conference For the third year running the IHBC Wales branch is working in partnership with the Civic Trust for Wales to host its annual conference on Friday 22 June. The theme is Conservation Areas in Crisis. Speakers will include Nigel Hewitson, head of planning at Howard Kennedy Solicitors and former legal director at English Heritage; John Punter, commissioner at the Design Commission for Wales and professor of urban design at Cardiff University; PrimroseWilson, former chair of the Historic Buildings Council for Northern Ireland and deputy chair of the National Heritage Memorial Fund. The afternoon session will consist of practical sessions. The venue is the National Library of Wales, Aberystwyth. The delegate rate is £80. Further details at www.civictrustwales.org. It’s in the bag Congratulations to Reg Morley, winner of the IHBC NorthWest newsletter’s caption competition. He is now the proud owner, apparently, of a bag of lime mortar. The runner up, Mike Scammell, had to be content with a bag of Portland cement. Hold your breath A marketing brochure for a development by Tidal Properties at Maryport in Cumbria offers ‘modern living spaces, with breathtaking views across the Solway Firth’. That’s not half of it. The scheme, apparently, is a redevelopment of a historic hamlet, designed by the architect and engineer Albert Gunn (1837–1904). Gunn achieved his aim of closely integrating everyday life with the rhythm of the tides by embedding homes into the harbour walls. The residents adapted to the need to seal up their houses when the tide was in: the original construction of the houses included the first waterproof door and window sealing units and dehumidifiers built into every room. The community worked a ‘tidal’ shift system. Half of them would be working the boats or mending nets outside while the other half would be inside their homes, getting much-needed rest and waiting for the receding tide before heading out to work. Unbelievable?You are right. The brochure and an associated exhibition turn out to be the work of the artist WilliamTitley, whose fevered brain conceived of Tidal Properties and its implausible scheme. Titley’s aim was to provoke the people of Maryport – whose regeneration is currently being planned – to think about the real-life issues involved in the processes of change. A few of the refurbished harbour wall properties are still available. Contact Tidal Properties for details. later medieval glass making, Kempe glass illuminates over 5,000 churches and cathedrals. Visit www.visitchurches.org.uk to book tickets for the Bodley and Kempe events. Climate revolution A lifesaving eco-house is being planted at the Eden Project to raise awareness of the impact of climate change on communities worldwide. Visitors will be able to step out of the biomes into the homes of Central American, African and Asian people, and experience a little of the reality of trying the survive the daily challenges of a changing climate. The eco-house, created by Christian Aid, is situated in the centre of the Eden Project against the backdrop of the biomes. It is part of the Eden Project’s Climate Revolution programme, which highlights the effects of global warming. Part of the display focuses on the UK. Christian Aid and the Eden Project are hoping it will inspire people to take action on climate change by reducing their own carbon emissions, adapting their lifestyles and campaigning for more government action to stop global warming. The eco-house will be at Eden for a limited time period, closing on 3 September 2007. New for old The Clore Learning Centre is a new resource for Hampton Court Palace, comprising a new single-storey reception building and refurbishment of the 17th century Barrack Block to provide educational facilities for visitors. The most significant building to have been built at Hampton Court for more than 150 years, it has presented a rare opportunity to integrate a new building within such a significant historic landscape. The form and orientation of the new reception building takes cues from the Palace roofscape and famous chimneys, the linear form of the Barrack Block building and the brick walls, both in adjacent historic buildings and in the immediate landscape of the palace grounds. The new single-storey steel framed building will provide teaching and support spaces as well as exhibition facilities to help visitor groups interpret the history of Hampton Court Palace. The new building is predominantly clothed in English hand-made imperial bricks and plain tiles, with seasoned oak for the glazed elevations. The Clore Learning Centre (photos: Paul Grogan) Albert Gunn’s waterproof masterpiece
C O N T E X T 9 9 : M A Y 2 0 0 7 ‘FOR THE first time branch membership has risen above 100. This is a great achievement and worthy of celebration. However, behind our rising overall membership hides a decline in support among local authority conservation officers, traditionally the core of our membership. ‘Looking at the attendance lists at recent conservation officers groups makes depressing reading. For example, Cheshire Conservation Officers Forum in December was attended by eight officers of whom only four were IHBC members. Merseyside Conservation Officers Group in the same month was attended by nine officers, of whom only five were IHBC members. ‘Worst of all, Lancashire Conservation Officers Group in November was attended by 10 officers of whom a mere two were IHBC members. Membership among English Heritage staff in Manchester is pathetic. Incredibly, there are only two IHBC members currently employed at Canada House. ‘This probably says a lot about employers’ attitudes to trained conservation staff and the said officers’ commitment to ongoing professional training. One recent Conservation Officers Group was memorable for a non-IHBC conservation officer (employed for at least two years within a design and conservation team of other non-IHBC members) asking if anyone could advise which Pevsner covered her authority.’ From an editorial by Peter Hoey in IHBC NorthWest, the newsletter of the North West Branch of the IHBC ‘the mayor of Moscow for the last 15 years,Yuri Luzhkov, wants Moscow architecture of all periods to grace his city…The Luzhkov style of romantic historicism is derided by western critics. To The Times’ Marcus Binney it wavers from “ersatz replica to bloated post-modernism”. To the New York Times it is pastiche “theme park Russia”. The guidebooks refer to kitsch and Disneyland.Yet they do not deride the reproduction Palladian mansions of the tsarist suburb of Arbatz, let alone the Gothic cathedrals of Europe, almost all of them in whole or part 19th century. Are the post-Reformation north and west fronts of Westminster Abbey “pastiches”? ‘Some of this criticism is valid. Luzhkov’s activities are about to be damned in a devastating report by the valiant Moscow Architectural Preservation Society, cataloguing the loss not just of major monuments under his regime but of hundreds of courtyards, terraces and quaysides. The mayor is said to have staged nothing less than “an assault on the dense and delicate fabric” of Moscow, a far more interesting city architecturally that St Petersburg. ‘Less worthy of criticism is the Moscow that Luzhkov has struggled to create. He at least cares, and thank goodness he is a man in a hurry, given what may follow him. The pressure to mimic Ken Livingstone in London and seek a pastiche Manhattan to enrich the oligarchs must have been strong. The result would have been the “edifice egotism” that is now pepperpotting the London skyline, and turned postreunification Berlin into a joyless architectural gallery.’ Simon Jenkins writing in the Guardian Richard Holder, 1956–2007 Richard Holder was educated at Bedales and then attended Reading University, where he gained a BA (Hons) in the History of Art and Architecture. He was awarded a PhD from the same university in the 1980s for his work on Victorian and Edwardian town halls in England. He had inherited his early interest in Victorian architecture from his father. Following a period as a fieldworker for listing buildings in the Accelerated Resurvey of historic buildings established by Michael Heseltine in the 1980s, when he worked in Oxfordshire and Berkshire, Richard went back to his first love, Victorian architecture. He joined the Victorian Society as casework officer, eventually becoming senior architectural advisor. He was a vigorous champion of Victorian buildings on behalf of the society for much of the late 1980s and 1990s and was also a very effective advocate on their behalf, speaking at conferences, and organising study tours and visits for their members. He left the society after about 15 years of service to concentrate on restoring the family home, a listed 15th-century hall house, which was completed shortly before his death from colon cancer at Easter. An early member of the IHBC, Richard contributed to branch conferences and attended a number of annual schools, where he could usually be relied upon to attempt at least a couple of dances at the traditional Saturday night party. He will be missed. Nigel Barker In memory of…
C O N T E X T 9 9 : M A Y 2 0 0 7 Periodically… Items in the latest issue of TheVictorian (No 24, March 2007) express alarm about the fate of Victorian schools. This reviewer recalled the excellent SAVE report focusing on the plight of urban schools in England and Wales. It contained essays from leading figures and over 100 illustrated pages emphasising those either under threat or converted to new use. It is sobering to recall that this report, Beacons of Learning, appeared over a decade ago. The crisis over the retention of Victorian and Edwardian schools is therefore not new, but the edition of the magazine is devoted to the impact of the government’s recently initiated modernisation of state schools, with secondary education facilities as a priority. Despite helpful English Heritage policy advice and a conference last November in London entitled ‘Learning from the Past: the future of historic school buildings’, the Victorian Society believes that some cases that have come to their attention bear the hallmarks of hasty and poor decisionmaking in relation to the heritage value. A helpful and nicely illustrated article by Joe Holyoak deals with the challenges presented by the government’s current programme. It is not difficult to see that sympathy for this building type in government and among education authorities is often based on perceptions of and prejudices against the past concepts of an inadequate education system, embodied in architecture of a long vanished era. Understanding the interest and diversity of the resource can inform decisions about the value of school. A photo-essay of Manchester board schools (prompted by the 1870 Education Act) shows excellent examples surveyed by Samantha Barnes under a research scholarship made under the Alan Baxter Foundation. The editorial highlights a case being fought by SAVE over a fine Grade II listed school building and local landmark facing demolition at Easington, County Durham. Sold by the county council for £1, it has passed through a succession of developers. Each in turn has inflated its hope value, standing now at £250,000. Unloved by the locals for its associations with the local pit, this is not situated in an area where it might be snapped up for a smart or trendy residential conversion. This suggests that is as necessary to have realistic expectations of the property market as it is to understand the community and cultural benefits. This issue of TheVictorian has a twopage guide to accessing information on the web about the retention and reinstatement of historic windows. The most recent issue of the Journal of Architectural Conservation (Vol 13, No 1) concerns itself very much with practicalities. Especially notable are two articles which deal the resolution of structural problems. Simon Bennett explains how unsympathetic interventions to correct a loss of stiffness in a 12m floor span at the Grade I Somerset House in London were overcome. In the past, hangers had been hidden in later partitioning walls of an (originally) large single room. Below is located the Seaman’s Hall, the main reception space for the whole of Somerset House. Highly interventionist solutions to stiffen up the floor while allowing the hangers to be removed were clearly inappropriate. The solution involved careful understanding of the original structural action of the floor, and reversing original flaws evident quite early after the building’s completion at the end of the 18th century. Bennett describes providing ‘a helping hand’ allowing the restoration of the original configuration and removal of the hangers. The structural analysis and solutions are shown by some informative illustrations. Equally informative is an article by Paul Begg about the more prosaic but no less important and far more common phenomenon of historic timber cantilever staircases.While discussions of stone examples appear occasionally, the author correctly asserts that timber examples appear to have been all but ignored.Yet, they are often remarkably refined, the designs being exceptionally elegant and structurally efficient but still easy to construct. Begg has used the detailed examination of one example from around 1800 to show how the design had developed to an integrated, minimal structural form, where all the components contribute to the structural integrity. He shows how important it is to understand this when the repair or reinstatement of elements may affect the overall structural stability. It is a valuable addition to the literature. Understanding materials is the theme of an article (the first of two) by David Hughes, Simon Swann and Alan Gardner about the origins and properties of Roman cement. Despite
C O N T E X T 9 9 : M A Y 2 0 0 7 its short-term technological significance after its patent in 1796, it has left a legacy of fine 19th and early 20th century buildings. The construction materials of these need to be properly understood by those responsible for their conservation. In comparison to currently available hydraulic limes, the availability of Roman cement is limited (there is only a single natural cement on the European market – the Prompt brand supplied by Vicat). The EU is funding a project through its ROCEM project to address both the loss of the contemporary technology and the lack of suitable materials. The authors describe the material itself; (historical) sources and their characteristics; composition; and applications. They analyse 19th century mortars and conclude that as their composition has become better understood, attention needs to be given to the varying mix proportions offered by different materials suppliers (based on the concept that Roman cement contained its own aggregate). This in turn has led to a search for suitable binders and mortars, and has rekindled interest in the manufacture of Roman cements. Although the architecture and historical development of St George’s Hall in Liverpool, widely regarded as the finest neo-classical building in the world, has been extensively documented, the recent work to the building, including changes of use and meeting access requirements, have not appeared much (if at all) in print. The building was designed to accommodate disparate uses, but ones with very specific spatial requirements. Robert Chambers has described the work being completed to reopen the building to the public in 2007, and the philosophy behind the interventions and their basis in relation to the surrounding context. Other articles of interest include a brief history by Alice Yates and Jaqui Goddard of the evolution, role and future challenges in the advocacy of the roles of the eight National Trusts in Australia (one per state or territory); and an article by Enrico Fodde of the University of Bath about the relationship between fired-earth structures and sulphate attack, based on a case study in Pakistan. While awaiting the latest issue of The Twentieth Century Society Newsletter your reviewer has also received the occasional publication in the Twentieth Century Society Architecture series (No 8) entitled British Modern: architecture and design in the 1930s. Containing eight substantial essays, it runs to nearly 140 well-illustrated pages. All but one contribution can be traced back to a two-day conference in 1999, organised jointly by the society and the Design Museum (then showing the exhibition Modern Britain 1929– 39). Although it has taken until now to turn that material into a publication, and although some of the original conference papers are omitted (mainly on the visual and applied arts, rather than architecture), the wait has been worthwhile. The one original, previously unpublished piece is by Sir Nikolas Pevsner (a manuscript held at the Getty Museum in California). It ‘brings a fresh and non-parochial voice from the past’, encouraging appraisal of the British architectural and artistic achievements of the period. Other essays include Robert Elwall on the striking and influential architectural photography of the 1930s; Royston Foot on the life and work of Sir Owen Williams (architect of the Daily Express Building, Fleet Street, and the Boots Factory, Nottingham); John Allan on the rediscovery of Berthold Lubetkin (this was before the publication of Allan’s definitive biography); modernism and tradition in English sculpture (by Chris Stevens); the architectural education of Denys Lasdun in the 1930s (by Barnabas Calder); the iconic significance of Kensal House in London as a model of working-class, inter-war housing (by Elizabeth Darling); and, where we almost came in, school design in the 1930s (by Denis Clarke Hall). Bob Kindred MBE From ‘Buildings in English Art’ by John Piper, The Architect and Building News, 9 May 1941 there’s one very odd thing about painters who like drawing architecture. They hardly ever like drawing the architecture of their own time. I know perfectly well that I would rather paint a ruined abbey halfcovered with ivy and standing among long grass than I would paint it after it has been taken over by the Office of Works, when they have taken all the ivy off and mown all the grass with an Atco. And also I would rather paint a new house when it’s twenty years old than when it’s new. You can call it reaction, or prejudice, or anything you like – but sitting down to paint a new house would give me the same feeling as sitting down to paint a new-born baby. It’s just one of those things I’d rather not do.
C O N T E X T 9 9 : M A Y 2 0 0 7 SUPPORTING COLUMNS Dealing with delaminating walls It is possible to restore the faces of walls that delaminate, writes engineer Brian Morton, but care and ingenuity are necessary. Walls of historic buildings that are constructed of two skins (either of brickwork, stone or flint) which are not bonded together are generally something of a problem when bulges start to appear. On occasions, particularly in Victorian times when churches were re-ordered, a new flint face was applied. Sometimes there was a different, generally harder, mortar mix to the original. No attention was paid to any bonding between the old and the new face. The mortar packed against the old flint was the bonding agent. It had a limited life, of course. Some walls built with a rubble infill, with limited bonding stones through the thickness, are also prone to bulging. If the wall is not to be demolished and rebuilt, the engineer has to come up with a solution to save as much of the existing form of construction as possible. Historically, I have found that problems occur particularly with flint walls which, in this form, are usually built with rubble infill, whether they have been re-faced by the Victorians, or simply rely on the original form of construction. This would normally be perhaps a flint face of 150mm maximum on the internal and external faces. In the case of the east wall of the Suffolk church (pictured above), the wall had been re-faced, probably by a benefactor in Victorian times. The hard mortar and flint material of the external face had allowed water penetration through the cracks, eventually washing the lime mortar backing at the top of the wall down to a lower level of the wall, causing the wall to bulge and subsequently fail. The process seems to be that water gets in, saturating the lime mortar backing, and the sun then shines causing this to dry out, breaking down the lime mortar into dust. This then migrates down behind the face. In the case of a house with a flint face, the gable end was simply constructed of two skins of rubble flint, a The east wall of this Suffolk church had been refaced, probably in Victorian times. Two skins of flint, with a void between them, form the wall of a house.
C O N T E X T 9 9 : M A Y 2 0 0 7 total overall thickness of no more than 250mm. Voids occurred throughout the height of the rear wall of the extension. In another case a 19th century wall (pictured below and p9 top), some 450–500mm thick, had been faced with a solid full-brick wall without any bonding into the face behind at all. There were fears that the outer face would fall away when heavy building construction started on the adjoining site. The method for dealing with such situations involved providing some temporary support for the external wall face. The usual way of doing this would be to use extensive raking shores, as indeed was the case originally when I looked at the brick wall. Our practice has developed a method for clamping walls through their thickness. We have used vertical timbers on the external face with holes and then bolts through the wall into further timbers internally, thus clamping the wall to prevent its collapse. We have used this system in very much more difficult circumstances to restrain the external faces of flint and stone buildings. The photograph on p9 shows a wall which has bulged away from its original position, with cracks forming at the back of the quoin stones. Initial ladder access to this wall, using the hand-banging technique, indicated that the wall was hollow behind its front face. It was held together simply by the hard mortar holding the external stones in place. The builder involved with this project was of the opinion that it would be necessary to take the whole wall down and rebuild it. He refused to carry out the work based on the clamping method. I appealed to the Engineering Division of English Heritage, which sent one of its engineers. He agreed with my clamping approach.Throughout the height of The gable end of this house was constructed out of two thin skins of rubble flint. This 19th century wall had been faced with a solid full-brick wall without any bonding. Clamping timbers through the wall’s thickness prevents collapse temporarily. The bulging wall was hollow behind its front face.
C O N T E X T 9 9 : M A Y 2 0 0 7 the wall scaffold boards would be bolted to the face of the wall, and through the wall, to further restraining timbers on the internal face (pictured in the two photos above). The horizontal boards were placed at 700mm centres up the height of the wall. When the wall was securely held, the contractor made a series of holes beneath the lower plank, allowed the dust and filling behind to fall out. He then made good this hole using stone on stone, with very little mortar between. He used stainless steel ties drilled into the backing construction and made good with a hydraulic lime-based mortar. This process carried on beneath the bottom plank using an underpinning hit-and-miss approach. When this was completed he went in above this plank, took out the stones immediately behind it, and consolidated those before cutting out further holes between the two planks above.This system worked well, saving the wall, and making significant savings in cost. In another case, a church gable constructed in flint had collapsed over perhaps more than half the length of the wall. The solid structure behind suggested that the remaining facing flints, where hollow behind, could be taken off and the outer face rebuilt with the original flint materials, starting from the bottom and working up.This is a straightforward situation that is fairly easy to deal with. Where the outer face is bulging away from the inner face (in the round tower churches of East Anglia, for example), we simply cut out the flintwork locally, carefully, allowing the flint over the new opening to arch over the hole and rebuild this incorporating stainless steel wire formed into ties. This is bedded into raked-out mortar in the thickness of the main wall. These ties would be formed of 4mm diameter stainless steel, bent on site by the contractor to a butterfly shape. It has been suggested to me that resins could be used for bedding these into the mortar, but we have used these only in extreme circumstances. This is simply because we are not sure of the strength of the interface between the resin and the lime mortar of the original construction. In another case, the wall of a house constructed of two skins of flint rubble has delaminated over its whole height (pictured on p8 top). The photograph on p7 shows the extent of that delamination, leaving a skin externally anything between 100mm–150mm. A section of this, probably two metres in diameter, had simply fallen and the wall below that was bulging. The problem associated with this, following our banging test, indicated that the wall was unsound over its whole height, perhaps some six metres. There were clearly dangers in attempting to do anything to the wall. After initially being baffled as to how we could save the remainder of the face, we have investigated grouting the cavity from ground floor level to the point where the collapse had occurred, to form a good base for either taking down areas of the upper wall and rebuilding on an underpinning basis. Alternatively we could grout the wall, depending on the success of our work to the lower section. The method of grouting from the bottom up is to break out small areas of the wall at perhaps 600mm heights throughout the wall, checking all the time with further small holes to see where the grout has penetrated. Extreme care is necessary in this process as too much pressure from the grout could cause the wall to burst. The grout has to be breathable at the same rate as the wall, particularly the pointing. Otherwise, as has happened to the east wall at Lincoln Cathedral, the hard grout inserted becomes a water barrier and the wall will not perform as it has historically. This results in the need to replace the outer face at maybe 30-year intervals. The stone becomes saturated, the water freezes and the stone breaks down. Brian Morton MBE is a consultant to the Morton Partnership, the practice he formed in 1966. A solid wall with no bonding raised fears that the outer face would fall away. Scaffold board bolted through the wall makes it safe while repairs are carried out.
10 C O N T E X T 9 9 : M A Y 2 0 0 7 How to preserve and enhance the conservation environment Figure 2 – the Conservation Rooflight® Figure 1 - Traditional cast-iron rooflight Characteristics of a Victorian cast-iron rooflight • Very low in profile - nominally flush to the roof tiles • Single-glazed panels divided into narrow strips by real glazing bars • Fine lines and relatively deep modeling of the putty to the glazing bars and edges • No overtly modern materials used - traditional flashings/soakers • Poor insulation and weather-tightness performance combined with condensation and maintenance problems Characteristics of • Very low in profile - nominally flush to the roof tiles • Double-glazed panels divided into narrow strips by real glazing bars, but with appearance of single-glazing at the cill • Fine lines and relatively deep modeling of silicone replicating the putty to the glazing bars and edges • No overtly modern materials used - traditional flashings/soakers • No condensation problems due to patented Thermoliner® - thermal lining incorporating drainage channels • Proven performance – exceeds BS6375: Part 1:1989 (weathertightness), U Value of 1.7W/m2 K, BS Kite marked glazing • Wide range of ironmongery and glazing options including ActivTM self-cleaning glass Figure 1 is an original Victorian cast-iron rooflight. In order to preserve and enhance a traditional or historic property the visual characteristics of new or replacement rooflights should closely match the original cast-iron ones. In addition modern standards of insulation and weather tightness must be provided. Often modern conservation-style rooflights meet performance criteria, but most fail to match the details of the original cast-iron models due to their broad sections, aluminium fronting and mock glazing bars. The Conservation Rooflight® from the Rooflight Company offers the largest size range in the UK as well as a bespoke design service, which means that any size or shape can be accommodated. For detailed case studies, visit www.therooflightcompany.co.uk or contact 01993 833108 or email info@therooflightcompany.co.uk for a brochure. the spec i f i e r ’ s cho i ce . . .
C O N T E X T 9 9 : M A Y 2 0 0 7 11 IHBC North West Branch Conference Cosmopolitans, style hounds and traditionals Keith Parsons writes: Despite the rising temperatures that we have seen during recent British summers, it is not the UK’s climate that fuels the British tourist industry. Tourism depends on its so-called attractions, because these provide the reason for people to leave their homes in the first place. Tourism in Britain continues to be a boom industry. The turnover of shops in tourist centres like Chester andYork, for example, tends to be considerably higher than in other towns and cities. Heritage became the buzzword in tourism during the 1990s. Heritage tourism can be defined as tourism centred on what we have inherited, which can mean anything from the historic environment to works of art. The fortunes of tourist attractions, not to mention many tourism-related jobs, largely depend on the work of conservation and amenity groups. The IHBC NorthWest Branch organised a day conference on the theme of heritage tourism at the Liverpool Medical Institute. In his introduction, Graham Boxer of the Liverpool Culture Company set the scene by outlining the value of heritage in terms of heritage-led regeneration, through its role in identity, social cohesion and heritage tourism. He explained that Liverpool’s heritage assets made the city the place it was. Phil Reddy of the Northwest Development Agency (NWDA) said that seeing heritage as a springboard for regeneration was a key to the NWDA’s economic strategy. The NWDA saw the sustainable growth of heritage tourism as vital to the economy of places like the Liverpool world heritage site, Chester and the Lake District. Reddy drew a distinction between tourism and the visitor economy. The former was a people-centred concept, whereas the latter was a place-centred concept. Although there was a tension between economic benefit and heritage protection, ‘tourism people’ and ‘heritage people’ agreed that heritage mattered. Contemporary culture was anchored in heritage, Reddy said. It exploited places and spaces, and it went beyond that.We needed to raise our ambitions to achieve higher quality environments. Chris Brown of Visit Chester and Cheshire talked about development plans for sustainable tourism. Chester was now the third most popular historic city, behind Bath andYork. An integrated culture and visitor management programme had been launched with the aim of making Chester a ‘must-see European historic city’ by 2015. Brown recognised the need to increase the visitor numbers and improve the heritage product. Chester would face competition not only from Bath and York, but also from the emerging Eastern European destinations. The objective of the programme was to improve visitor management by encouraging visitors to discover other parts of the city, and developing and improving attractions. Brown outlined the vision of Chester as a ‘boutique city’. (Chester’s Place Marketing Strategy states that ‘the term “boutique” evokes an appealing combination of heritage, design-driven quality, and contemporary facilities in an environment that is compact, accessible and manageable from the perspective of both visitors and residents.’) This meant that Chester had to be world class, as well as being a historic city; it had to have economic energy and offer retail excellence. It was important to get different sectors to talk to each other and develop the visitor economy Leighton Hall, Carnforth, Lancashire, a privately owned historic property open to the public
12 C O N T E X T 9 9 : M A Y 2 0 0 7 in the context of the local economy, especially since one in three jobs related to tourism. There needed to be a balance between community, tourism and the environment. Visitors wanted interactive, high-quality environments, not glasscase museums. It was important to get the welcome right, so Chester station had to be a gateway. The public relations and the infrastructure (including public WCs) had to be right too. David Geddes of Locum Consulting talked about understanding visitor behaviour. He cited findings from the north west visitor survey. Visitors tended to look for a range of attractions rather than a single one. Education was not a high priority to the visitor, whereas entertainment was. Geddes referred his audience to the Ark Leisure Segmentation model. This was a tool for identifying different categories of visitors, including ‘cosmopolitans’, ‘style hounds’ and ‘traditionals’, to name three. Different destinations appealed to different visitor types. This had implications when it came to reinventing town centres. Geddes discussed how Stockport could move away from simply providing 1970/80s shopping malls by targeting the Under Banks area, for example, with its old town ambience. Southport had become a down-market bucketand-spade place. It needed to focus on Lord Street if it was going to go back up market. John Hinchliffe of Liverpool City Council talked about the city’s world heritage site. The statement of significance identified Liverpool’s historical and intangible themes, and its urban landscape. Visitors came for both aspects, Hinchliffe said. The world heritage site management plan emphasised that visitor management issues forged an identity for the city. An integrated visitor management strategy was in place. The world heritage site was a key theme in strategic tourism documents as it would continue beyond the city’s year as the European Capital of Culture in 2008. Pat Hansell of Blackpool Council explained how the resort had previously focused on making money rather than heritage. Although Blackpool is the second most popular destination, according to the north west visitor survey, the town has serious problems. These include unemployment, transients, and educational underachievement: hence the need for the regeneration company and the master plan. Hansell noted that the recentlylaunched heritage strategy focused on ‘the people of Blackpool’. The town was preparing a world heritage bid, focusing on the resort’s importance in the industrial revolution as an ‘industrial landscape of the seaside’. The town had a unique heritage of leisure architecture and technical innovation. The regeneration plans for Blackpool were based on much more than just a super casino, she said. Sara Burdett of the National Trust talked about access to historic sites. There was an educational theme at the trust’s sites, although the aim was increasing awareness, not formal education. Burdett focused on the Chambré Hardman Centre at the former home of Liverpool photographer Edward Chambré Hardman in Rodney Street, Liverpool, with its photographic studios and photographic archive. Burdett cited the National Trust slogan: ‘Forever for everyone’. Photographs fitted in with this theme. The presentation highlighted the conflict between making the photographic archive accessible and preserving the delicate heritage asset. After a series of the tours, Karl Creaser of English Heritage talked about the contribution of local heritage. Major sites and landmark buildings might be of national importance, but local buildings provided local identity. Creaser took his audience on a whistle-stop tour across the north-west region, where a range of initiatives were engaging people and strengthening communities. Creaser said that the Hidden Britain scheme had generated billions of pounds in tourism for the north west. He also cited two examples of heritage-led regeneration. The high street (shop front) project in Lytham St Annes had seen vacancy rates drop from 30 per cent to three per cent. A regeneration scheme in Ulverston had seen house prices rise by 15 per cent. Local heritage was important for locals, but visitors and residents valued local distinctiveness. Difference was marked more often by many small buildings and by local stories, than by large buildings. Andrew Backhouse of Culture NorthWest. Backhouse talked about making connections. There were plenty of projects and a great deal of silo thinking, he said, but good practice could be shared through networking. He cited Carlisle Castle, which was cut off from the town by a dual carriageway, and Clitheroe, where a one-way street ran away from the castle rather than towards it. Backhouse advocated making connections both in a physical sense and in terms of linking, and relating to regional strategy. It was important for people working on local projects to see the bigger picture, he said. In discussion the need for a quality environment, rather than just heritage attractions, was emphasised. Infrastructure was important:WCs, shops, cafes and restaurants, as well as transport, such as like shuttle buses. The conference underlined the point that the conservation community needed to be proactive, rather than reactive. Heritage has an important role to play in regeneration and the local economy, and heritage tourism is a key to that. Keith Parsons, principal lecturer in the department of built environment, University of Central Lancashire Waterloo Pavilions, Blackburn, a recent regeneration scheme within the cathedral close at Blackburn
C O N T E X T 9 9 : M A Y 2 0 0 7 13 The environmental impact of a building throughout its lifetime (Harris, 1998) Input Stage Output Energy (Earthmoving) Site preparation Carbon dioxide Dirt Noise Loss of amenity Loss of trees Loss of wildlife Energy Components Raw materials Construction Carbon dioxide Dirt Noise Waste materials Energy Materials (Maintenance and refurbishment) Use Carbon dioxide Indoor effects (asthma, sick building syndrome) Energy Demolition Carbon dioxide Dirt Waste material DAVID DREWE Embodied energy: new build v refurbishment When considering the energy cost of development, it should not be assumed that a new energy-efficient building will always be the best option. Embodied energy is the energy tied up in materials as a result of extraction, manufacture, production and delivery. The embodied energy in buildings is that used to produce building materials, to transport them to site and to build with them. The idea of embodied energy has been the subject of research for many years. It has been proposed that energy, including that embodied in materials, could be used as an indicator of environmental impacts. Ted Kesik (2002) quotes typical embodied energy values of some common building materials as 5,170 MJ/m3 for brick;139MJ/m3 for rockwool; 37,550 MJ/m3 for float glass; 1,380MJ/m3 for timber; and 3,770MJ/m3 for fibreboard. One of the arguments put forward for not demolishing buildings is the loss of the embodied energy contained in the existing stock. So lifetime energy should include the embodied energy of the initial construction, energy required for its operation, any improvements and finally the energy for demolition. Should the embodied energy contained within the materials of existing buildings be included in any assessment of total energy? While embodied energy has no doubt been used to construct the existing housing stock, it is in effect a sunken energy cost. The energy and the materials have already been consumed. They can now only be offset in part if the materials can be recycled, recovered or reused. When undertaking comparison calculations, the embodied energy in the original property is cancelled out, so it can be discounted. It is suggested therefore that the embodied energy of existing buildings is not part of any total energy comparison calculations. Is the existing dwelling favoured by ignoring its embodied energy? In the case of demolition and new build, the consequences of the demolition are the loss of the embodied energy and the resources contained in the existing property. This energy cost has to be considered as part of the price paid for undertaking the new build. For refurbishment, the total energy used is the embodied energy of existing materials, plus the embodied energy of materials used in refurbishment, plus the operating energy, plus the energy for demolition. For new build, the total energy used is the (loss of) embodied energy of existing materials (of the demolished house), plus the embodied energy of the new build materials, plus the operating energy, plus the energy for demolition. Embodied energy can be used as an indicator of environmental impacts. Buildings should have the lowest total lifetime energy use possible, indicating the lowest possible environmental impacts. The move towards sustainable development has required consideration of the wider social and economic impacts, as well as environmental ones. Energy use would appear to be able to be used as a good indicator for economic issues. Potential shortages as the result of conflicts, natural disasters or political unrest can lead to a direct impact on our economy. Energy can also be linked to a number of social issues. Pollution, as a result of the production and use of energy, can cause health problems and place increased demands on society to care for or treat those affected. Fuel poverty can add to these health problems, and results in some people experiencing a lower standard of living and financial hardship. The big impact of energy use is on climate change. Predicted increased flooding, higher extremes of summer temperature and water shortages will all affect society.The relationship between carbon dioxide emissions and energy makes energy a good indicator of potential climate damage. One of the most important issues to consider is that an energy-efficient building may use more energy over its lifetime then a less efficient building with a higher operating energy. The energy-efficient building would require not only more energy to construct but also more for maintenance of both its fabric and equipment. It should not therefore be assumed that a new energy-efficient building will always be the best option. References Harris, DJ (1998) ‘A quantitative approach to the assessment of the environmental impact of building materials’, Building and Environment, 34 Kesik, T (2002) ‘Perspectives on sustainability’, Architectural Science Forum, January 2002, www.canadianarchitect. com/asf/perspectives_ sustainability/index_ frameset.htm David Drewe is head of the building services engineering and safety team at English Heritage, and coordinator for the English Heritage Sustainable Development Board.
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