Technical issues in building conservation Institute of Historic Building Conservation No 90 July 2005
Courses in Historic Building Conservation For a full course programme please contact Diana Rowsell, Head of Learning [email protected] Direct tel: 01243 811464 Fax: 01243 811475 England’s leading Museum of historic buildings and traditional rural life is a centre of excellence in building conservation and the use of traditional tools, materials and methods. The 48 historic buildings on site give the Museum an unrivalled teaching resource in this specialised field, with much scope for practical, hands-on experience. Many courses are based in the new and innovative Downland Gridshell workshop. All our courses are led by specialist practitioners currently working in their fields. Topics include Cob, flint and stone walls • Construction and repair of timber framed buildings • Repair of traditionally constructed brickwork and other wet trades • Traditional roofing methods • Lead work • Lecture days on Victorian and Georgian traditions and industrial buildings • MSc in timber building conservation in its 6th cohort A series of 10 day schools in vernacular architecture will be launched in autumn 2005
C O N T E X T 9 0 : J U LY 2 0 0 5 1 Context Cover: Concrete spalling from the underside of the canopy on a 1960s building, due to reinforcing rods rusting. Ian Brocklebank discusses new approaches to repairing reinforced concrete on page 30. Technically, it’s a knockout Editorial care. The solution, he writes, lies in more training; better communication between professionals, craftspeople and technicians; and using professionals at the right time. Other technical issues involve resolving conflicting aims. Part L of the building regulations, for example, raises the question of how to improve energy efficiency while protecting the character and appearance of historic buildings (see p21). The use of soft capping with soils and turfs to conserve exposed walls, to take another example (see p22), raises conflicting issues of appearance, preservation and biodiversity. In each case, decisions which may be based on politics and values depend on detailed technical knowledge. In the case of thatch, that knowledge involves new insights into the performance of traditional materials. Reinforced concrete, by contrast, is a relatively new material. As Ian Brocklebank notes (p30), few people are expert in repair techniques such as realkalisation and impressed current cathodic protection. With insulated, lime breathing floors, Alison Henry writes that the news of this technology has not reached the wider audience that would benefit from it (p11). Presenting such technical matters to that audience is the aim of this issue of Context, which Alison and the IHBC technical subcommittee have kindly helped put together. If you want to provoke a fist-fight, just get two experts on thatch arguing over the relative merits of water reed and combed wheat reed. The inspector in a recent planning appeal that turned on this issue stated that ‘no firm conclusion can be drawn on the time that a water reed roof is likely to last on this building’.Well, let’s not rush things, but in this case the building had been thatched for 600 years. Can we not learn from experience? Why do we need to get all technical? The answer in this case is that there may be plenty of knowledge about each kind of thatching material, but not necessarily about how they compare in use in the same part of the country. As Alison Henry (p13) points out, ‘there have been no empirical studies to establish the relative longevity of different materials, and the anecdotal evidence is inconclusive.’ Nor are the issues simple. The inspector in that thatching case also took into account the different impacts of the use of each kind of thatch on farming and landscape management practices, and their contribution to farm diversification. In some other situations the technical issues are clear enough, but there is still the potential to mar a valued building. Ian Hume (p17) tells some horror stories of services being installed in historic buildings without proper Briefing 2 Out of Context 3 Periodically 4 Legal Briefing Charles Mynors and Alex Booth 6 New developments in insulated, breathing lime floors Alison Henry 11 Fact and fiction on traditional thatch Alison Henry 13 Installing services in historic buildings Ian Hume 17 Part L: a question of compromise ChrisWood 19 Soft capping: justifying a return to the picturesque ChrisWood 22 Winning stone from local sources ChrisWood 27 The problem with reinforced concrete Ian Brocklebank 30 Characterisation and values in Milton Keynes Graham Steaggles and Jeremy Lake 34 Notes from the chair 37 Membership notes; Vox pop 38 Book reviews 39 Products and services 41 �������������������� ��������������������� ���������������� ������������������������������������������� 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 [email protected] Chairman: JohnYates email [email protected] Vice Chair: Dave Chetwyn email [email protected] Secretary: Richard Morrice email [email protected] Treasurer: Michael Knights email [email protected] Membership Secretary: Mike Lea email [email protected] Consultations Secretary: Dave Chetwyn email [email protected] Law & Practice Coordinator: Vacant email [email protected] Education Secretary: John Preston email [email protected] Publicity Secretary: Sarah Buckingham email [email protected] Director: Seán O’Reilly email [email protected] Branch Officers North: John Pendlebury Tel 0191 284 2119 NorthWest: Anthony Blacklay Tel 01270 610050 Yorkshire: Keith Knight Tel 01904 658482 West Midlands: Karen Holyoake Tel 01384 826891 East Midlands: Fiona Newton Tel 01507 601111 South: Gill Butter Tel 02380 285324 SouthWest: Colin Ellis Tel 01305 838334 East Anglia: Mike McConnell Tel 01284 735057 South East: Paul Barker Tel 01825 760705 London: David McDonald Tel 020 8881 6724 Scotland: Charles Strang Tel 01835 822560 Wales: Nathan Blanchard Tel 01824 708048 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 [email protected]
2 C O N T E X T 9 0 : J U LY 2 0 0 5 Context Briefing Copy deadlines Context is published five times a year, in March, May, July, September and November. Remaining copy deadlines in 2005 are: Issue Date September, Issue 91 15 July November, Issue 92 16 September Churchyard monuments at risk A recent survey of over 250 Grade I and Grade II* buildings and structures in South Somerset revealed that, of the 22 churchyard monuments and crosses included, 19 were in fair, poor or very poor condition, and were at risk. There are a further 470 Grade II listed churchyard monuments, and if the figures for Grade I and II* structures are extrapolated there could be something in the region of 420 listed churchyard monuments at risk. The type of remedial work required varies from removal of vegetation and repointing to complete dismantling and reconstruction. Churchyard monuments are clearly a vulnerable type of structure. Very often the families of the deceased can not be tracked down. Although conservation work to such structures is often comparatively inexpensive, Editor Robert Cowan Editorial Coordinator Nigel Barker, 65Worplesdon Road, Guildford, Surrey GU2 9RT. Tel 01483 562 851 email [email protected] Editorial Board Nigel Barker (chair) Susan Brook (treasurer and IT) Nigel Crowe (main features) Peter de Figueiredo (book reviews) Julia Smith (IHBC branches) Michael Taylor (main features) Cartoons by Robert Cowan Context is distributed to all members of the Institute of Historic Building Conservation. © Institute of Historic Building Conservation 2005 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 [email protected] 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 those held by the IHBC nor 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. many parishes struggle to cope with maintaining the main church building, so there is little, if any, money available for churchyard structures. Grants are sometimes available, but these usually cover only a proportion of the cost, leaving the hard-pressed parish to find the rest. To address this problem South Somerset District Council set aside £15,000 from the Historic Buildings Grant budget to establish a Churchyard Monuments at Risk Grant Scheme. The scheme will run for three years from April 2004. The council was lucky in attracting some partnership funding from St Andrews Conservation Trust, which has pledged £1,000 a year, bringing the total fund available to £18,000 over three years. Jonathon McKechnie-Jarvis, who runs a similar scheme for table tombs in the Diocese of Gloucester, provided helpful advice. The scheme applies to listed churchyard monuments including chest tombs, headstones and crosses. Other listed structures such as lych gates and boundary walls are not eligible. In most cases the work eligible for grant aid will be the minimum necessary to stabilise the monument and slow down deterioration. The work may include all or some of the following: removing ivy and other woody plants growing in the joints; repointing; consolidating footings; removing iron cramps and fixings, and replacing with stainless steel; dowelling fractured stones; mortar repairs to eliminate water traps; consolidating friable stone; and dismantling and reconstruction. The rate of grant is 75 per cent for Grade II listed monuments and 95 per cent for Grade I and II* structures. It is hoped that offering a high rate of grant for a limited period will spur parochial church councils to tackle their problem monuments sooner rather than later. There was considerable interest in the scheme when it was launched, but only one project was completed in the first year. However, it is expected that there will be greater take up this year as there are several applications in the pipeline. Although the total amount of money available is small in comparison to the likely scale of the problem, the council hopes that the scheme will draw attention to the plight of churchyard monuments and may help to secure additional funding from charitable trusts. Grant offers are subject to the parochial church council agreeing to submit an annual maintenance checklist to ensure that the monument receives appropriate aftercare. It is hoped that this will also raise awareness of the need for maintenance of other monuments in the same churchyard. The scheme may spark the enthusiasm of some parishes to pursue additional funding, such as the Local Heritage Initiative, taking into account the wider conservation potential of graveyards, including their wildlife and green space value. Alison Henry, historic buildings advisor with South Somerset District Council A churchyard monument before and after.
C O N T E X T 9 0 : J U LY 2 0 0 5 3 COHT gets practical The COHT (Conservation of Historic Thatch) committee, inaugurated at a meeting at Reading University in 1999, has always recognised that tangible results would have to be delivered if it was not to be seen as just another talking shop in the conservation world. COHT’s aims are to promote the identification of buildings with surviving historic thatch; to promote educational initiatives for owners, thatchers, specifiers, conservation officers and any other relevant individuals or organisations; to identify and promote appropriate research projects; and to provide practical advice. The committee has been steadily expanding its membership to encompass all the disciplines required to achieve its goals, while exploring sources of possible designed, is intended as the first port of call for all matters relating to thatch. Jack Lewis Heritage Open Days Thousands of buildings and places across England will be throwing their doors open free of charge for Heritage Open Days 2005, Thursday 8 to Sunday 11 September. Coordinated by the Civic Trust and supported by English Heritage, highlights of this annual celebration of architecture, history and culture include: • Murdoch House in Redruth, Cornwall, home of William Murdoch, which the inventor first lit with coal gas in 1792 and where replicas of William Murdoch’s original steam engine will be on display. • Chatham Memorial Synagogue in Rochester, built in 1861 by Simon Magnus in memory of his son Lazarus on the site of a even older synagogue. • Watford Palace Theatre in Hertfordshire, one of the most elegant Edwardian theatres in Britain, which has just reopened following a £8.7 million refurbishment. • The Hermon Chapel in Oswestry, Shropshire, a magnificent Grade II* listedWelsh chapel from 1862 with original pulpit, pew boxes and galleries. For further information, visit www.heritageopendays.org or call 020 7539 7924. Lime in a cold climate The Annual Conference and Gathering of the Building Limes Forum on ‘Lime in a Cold Climate’ is to be held in Bergen, Norway from 30 September to 2 October 2005. The venue is the Bryggen Museum, part of the BryggenWorld Heritage Site on the north side of Vågen, the old harbour of Bergen. Stretching to the east are the historic timber wharves and warehouses which form the most famous part of the site, while two blocks to the west is Bergenhus Castle. Over the four days prior to the conference a training course is to be held for masons, based on practical works at a range of different historic sites in Bergen. Masons from Scotland originally led the building of Haakonshallen, the Great Hall at Bergenhus castle in the late 13th century, and had a major influence on the masonry traditions in western Norway. Details at www.buildinglimesforum.org.uk ‘WHY ARE they knocking them down? If it is economically viable, they should do them up. Are they going to knock out the centre of Liverpool again? That’s what they did before. They moved everybody to high-rise apartments outside the city and forgot to rebuild.’ Former Beatle Ringo Starr on the proposed demolition (under the government’s Pathfinder scheme) of the Liverpool terrace where he used to live. It has since been reprieved. ‘STARVED of support, imprisoned by political correctness, bullied into acquiescence, the people tasked to preserve Britain’s historic sites are fighting a losing battle against the deputy prime minister’s wrecking ball. Why should we trust Two Jags with our heritage?… In October 2004, when the Conservative MP Andrew Rosindell asked how many English Heritage sites the secretary of state had visited in the previous 12 months, he received the answer “none”. She “has not had an opportunity”, explained the sports minister Richard Caborn… The sense of being undervalued and under-rewarded trickles down through [English Heritage] like oil into sand. Staff salaries used to be linked to civil-service pay grades, but have been decoupled and have fallen far behind. Some staff with managerial responsibilities are working for as little as £17,000 a year.’ Richard Girling writing in the Sunday Times. ‘PEOPLE sometimes have wanted to portray us as a beleaguered organisation, but don’t believe a word of it…We still have the largest historic environment research capability in Europe… Last year our visitor business grew by 8.5 per cent gross. That’s as much as Tesco. If we were a PLC I would buy shares in us… Like that unlikely heritage hero Baldrick, English Heritage can now say with confidence that we “have a cunning plan”.’ Chief executive Simon Thurley launching the English Heritage Strategy 2005-10. funding for projects and publications. It sees the imminent launch of its first publication (jointly with the IHBC) Growing Straw for Thatching as the first of many useful additions to available conservation literature. Possible topics for future publications include advice on fire prevention in thatch buildings, guidance on the thatching of traditional farm buildings, and a national list of thatchers and straw growers. Current initiatives include discussions with the British Reed Growers Association on promoting the responsible use of indigenous water reed, and continuing dialogue with DEFRA and NIAB (National Institute of Agricultural Botany) to find a practical way of legally obtaining seed of, and growing, unlicensed wheat varieties. Experience has shown that older varieties of wheat provided better-quality straw, which consistently performed well as thatch. The survival of a viable straw thatching tradition in England is considered to be of international significance, and the committee sees the availability of older wheat varieties as one of the most important current issues. A COHT website, currently being
4 C O N T E X T 9 0 : J U LY 2 0 0 5 Periodically… As this reviewer had occasion to remark in the May 2004 column, one of the unintended charms of ASCHB Transactions is the unpredictability of its arrival. Volume 27 for 20023 has just appeared but the editors aim to catch up chronologically by 2006. Arrival always merits the wait, however, and anyone who is not a member of the Association for Studies in the Conservation of Historic Buildings will find this issue worth seeking out. Changes of printer and format have resulted in very pleasing new typography and a move to colour illustrations – a major bonus. The range of material is wide and the six articles exemplify the breadth of current conservation practice. It has been a delight to see in execution the reinstatement of major decorative schemes for important historic buildings, lost to either war damage or changes of fashion. Ian Bristow explains the research behind the reintroduction of the important polychromatic decorative designs for the hall and staircase of the British Museum by the Smirke brothers and decorator Leonard Collmann in 1847. Bristow explains in detail the combination of documentary research and physical investigation where original mid-19th century watercolours provided vital evidence; the contemporary interest in and use of ancient Greek sources for the decorations; and why the scheme when executed was so important. The reproduction of the colour illustrations here is especially telling. Decorative authenticity is also discussed by Alasdair Glass in his article about the re-presentation of the principal rooms at Osborne House in the care of English Heritage. This work was undertaken as part of a five-year centenary project that commenced in 1999 to commemorate the death of Queen Victoria at Osborne in 1901 and the opening to the public in 1904. The decorative schemes, soft furnishings and contents have been conserved and/or restored and some displaced items reinstated to show the rooms as they would have looked at the end of Victoria’s reign. Other articles worth highlighting include: the resolution of a difficult repair problem for a roofless ruined conduit house formerly serving Bolsover Castle, where meticulous investigation led to the discovery that the building had an unusual stone vaulted roof, which has been reinstated to end a period of serious vandalism; an invaluable account of repairs to the intricately detailed 1630s brickwork at Kew Palace involving fine, pennystruck pointing and the overall application of terracotta-coloured limewash to transform the perceptions of the building; and an account of the refurbishment of Brompton Barracks, Chatham – the largest barracks built during the Napoleonic Wars – where the interiors have been brought up to modern standards while conserving the historic character. Perhaps the most telling article in the Transactions is one of the most unusual. Robert Wyatt has used the 91 vernacular buildings photographed by W Galsworthy Davie (with additional notes and sketches by Guy Dawber) in BT Batsford’s 1904 book Old Cottages, Farm-houses and other Stone Buildings of the Cotswold District as an opportunity to compare the buildings a century later. Wyatt managed to find 70 of them (he thought a further eight had been demolished) and noted some interesting trends. The 25 or so small cottages had fared worst, with seven having been demolished, while many of the remainder had been enlarged by extensions or linked together. While the smaller houses seemed to have lasted better, of the 19 farmhouses only four are working farms today. Overall Wyatt felt that conservation had helped, with only two properties having lost their stone slate roofs, although inevitably many changes were detrimental but subtle. One of these is the disruptive visual impact wrought by the introduction of modern gutters and downpipes on buildings that would have relied on overhanging eaves to throw the water clear. Hardly an original front door survives and although leaded windows remain, flat modern glass has eliminated the sparkle. Delightful timber shutters have almost entirely disappeared. While complaints about roadside clutter and setting might well be expected, the creeping changes are instructive and well illustrated. So much for some current siren (and wrong-headed) voices suggesting that conservation professionals concentrate too much on the detail. The 13 before and after examples given are well worth the scrutiny for what they tell us about local diversity and conservation policy. The Spring edition of SPAB News (Vol 26, No 1) provides a simple guide to the issue of rising dampness. It makes clear that true rising damp is quite rare and often misdiagnosed. Inappropriate damp-proof courses account for a large amount of unnecessary work. As might be expected, breathability is a crucial aspect. Attention is also drawn to historic milestones and the neglect often suffered at the hands of parsimonious highway authorities. Many, it seems, were lost as a consequence of a War Office-inspired directive of 1939 to bury or deface milestones to delay an invading army (as the article pithily observes – ‘a rather Dad’s Army approach – the idea that the German
C O N T E X T 9 0 : J U LY 2 0 0 5 5 But SAVE’s activities are not confined to large buildings nor to London. The latest newsletter highlights the returning concern about the loss of K6 phone boxes as the entire population seems to own a mobile phone, and the loss of historic (usually unprotected) railway footbridges. Many with lattice ironwork, delicate cast-iron columns and capitals are being replaced by crude structures in the cause of greater disabled accessibility. One at risk at Moreton in March is illustrated, and SAVE would like to hear of threats to any others. On the subject of anniversaries and campaigning groups, Civic Focus, the magazine of the Civic Trust (Spring 2005) celebrates its 50th issue with 50 programmes, awards and activities that have defined its progress and influence since its inception. The issue also looks at what the trust believes is the seriously misguided Housing Market Renewal Initiative applied to Liverpool; and the extent to which the built environment encourages or deters anti-social behaviour – the theme of this year’s Civic Trust Awards conference. Finally, while on the subject of conferences, Natural Stone Specialist (April) reported on the enthusiasm at the England’s Heritage in Stone conference for the setting up of an English Stone Forum along the lines of the Scottish Stone Liaison Group. The Geoconservation Commission of the Geological Society that organised the conference in York clearly felt that sufficient interested people were present to make the initiative valid. The British Geological Survey and the National Stone Centre will take the troops would arrive without maps and compasses’). Sadly, it would seem that milestones are also becoming the subject of theft and trade interest, even appearing on eBay, despite being within the highway and therefore public property. In Britain there is a society or pressure group for almost every aspect of the built heritage, and the eponymous Milestone Society (www.milestonesociety.co.uk) is no exception. It may be worth contacting if your interest or remit extends to these undervalued items of street furniture. The Archaeologist (No 56, Spring 2005), the magazine of the Institute of Field Archaeologists, is mainly concerned with prehistoric Britain. But an article by Michael Nevell of Manchester University on ‘Building materials for the archaeologist’ does have some interesting observations about the way in which these can reveal extensive local, regional and national trade networks of a given period. Nevell gives an example of geographical distribution for the sources of building materials in Tameside. This is an underdeveloped area of research with potential significant interest. The SAVE Britain’s Heritage Newsletter (April-May 2005) highlights its 30th anniversary, during which it has maintained a high and effective profile. Its campaigning achievements will be the subject of an exhibition at the Victoria and Albert Museum in the autumn. SAVE’s polemical style will be known to many, as will many of the high-profile cases such as Number One Poultry in the 1980s and more recently the General Market at Smithfield. matter forward. In the May issue, matters of conservation interest included a report on the repairs of Dundas Aqueduct by John Rennie (this Grade I structure and Scheduled Ancient Monument carries the Kennet and Avon Canal over the River Avon near Bath) and a report on the work of the highly regarded Orton Trust, which for more than 30 years has been running training courses for stonemasons at weekends in a redundant church in Northamptonshire. Bob Kindred MBE Join the Civic Trust. See special offer details on page 44.
6 C O N T E X T 9 0 : J U LY 2 0 0 5 LEGAL BRIEFING World heritage sites World heritage sites will become increasingly significant, although those in the UK depend on existing designations to protect them, report Charles Mynors and Alex Booth. The Convention concerning the Protection of the World Cultural and Natural Heritage (usually referred to simply as the World Heritage Convention) was adopted by the General Conference of the United Nations Educational, Scientific and Cultural Organisation (UNESCO) at its 17th session in Paris in 1972. The preamble to the Convention recites that: ‘…the cultural heritage and the natural heritage are increasingly threatened with destruction not only by the traditional causes of decay, but also by changing social and economic conditions which aggravate the situation with even more formidable phenomena of damage or destruction; deterioration or disappearance of any item of the cultural or natural heritage constitutes a harmful impoverishment of the heritage of all the nations of the world.’ That applies of course – in theory – to all items of the cultural heritage, however localised their significance. But the convention is concerned principally with the items of more than local or even national significance. The preamble therefore goes on to note that ‘parts of the cultural or natural heritage are of outstanding interest and therefore need to be preserved as part of the world heritage of mankind as a whole’. It is against that background that the convention seeks to put in place what it refers to as ‘an effective system of collective protection of the cultural and natural heritage of outstanding universal value, organised on a permanent basis and in accordance with modern scientific methods’. Part I defines what is to be considered to be the cultural and natural heritage for the purposes of the convention, and imposes on individual state parties a duty to identify and delineate particular properties within its territory that fall within those definitions. Part II commits states to do all they can to ensure the identification, protection, conservation, presentation and transmission to future generations of the selected properties – each state party recognising that the duty to do that belongs primarily to that state. In particular, each state party to the convention undertakes that it will endeavour, so far as possible ‘to adopt a general policy which aims to give the cultural and natural heritage a function in the life of the community and to integrate the protection of that heritage into comprehensive planning programmes; [and] to take the appropriate legal, scientific, technical, administrative and financial measures necessary for the identification, protection, presentation and rehabilitation of this heritage’. Parts III and IV of the convention provide for a World Heritage Committee and a World Heritage Fund, both which have been in operation since 1976. In practice, the implementation of the convention is overseen in Paris by the UNESCO World Heritage Centre and its two advisory bodies – ICCROM (the International Centre for the Study for the Preservation and Restoration of Cultural Property), based in Rome, and ICOMOS (the International Council on Monuments and Sites), also based in Paris. The websites of each of these organisations should be visited for current information. And all state parties agree to cooperate with each other. Identification of the cultural heritage The following are considered as ‘cultural heritage’: ‘(1) monuments: architectural works, works of monumental sculpture and painting, elements or structures of an archaeological nature, inscriptions, cave dwellings and combinations of features, which are of outstanding universal value from the point of view of history, art or science; (2) groups of buildings: groups of separate or connected buildings which, because of their architecture, their homogeneity or their place in the landscape, are of outstanding universal value from the point of view of history, art or science; and (3) sites: works of man or the combined works of nature and of man, and areas including archaeological sites which are of outstanding universal value from the historical, aesthetic, ethnological or anthropological points of view.’ The duties of the World Heritage Committee include the definition of criteria by reference to which properties may be assessed for inclusion in the list. The current criteria are contained in the Operational Guidelines for the Implementation of the World Heritage Convention, updated most recently in February 2005. Those relating to the cultural heritage are as follows: ‘The Committee considers a property as having outstanding universal value if the property meets one or more of the following criteria. Nominated properties shall therefore: (i) represent a masterpiece At the heart of Liverpool’s world heritage site is the famous waterfront. The city was Britain’s preeminent commercial port in the 19th- and early 20thcenturies when Britain was a true world power.The grand docks, offices, banks, exchanges, warehouses and cultural buildings demonstrate Liverpool’s global importance.
C O N T E X T 9 0 : J U LY 2 0 0 5 7 considers that a property is suitable for inscription on the world heritage list, it must first include it on the tentative list for the country concerned – after consultation with all relevant stakeholders, including site managers, local and regional authorities, local communities, non-governmental organisations, and any other interested parties. That list is then periodically (usually around every ten years) updated, and submitted to the secretariat of the World Heritage Centre.This enables all concerned to consider whether it would be appropriate for the properties concerned to be nominated and inscribed, in the light of the criteria considered above. A property can only be nominated when it has been on the tentative list for at least a year. A state may then nominate a site to the secretariat. The advisory bodies will be consulted for their views, seeking further information from the nominating government where necessary. The World Heritage Committee, which meets once a year, in July, decides whether or not to inscribe the property on the list. A property that is rejected may not be nominated again, other than in exceptional circumstances, such as where new information comes forward. As for the extent of a world heritage site, the Operational Guidelines state that the delineation of boundaries is an essential requirement in the establishment of effective protection of nominated properties. Thus, for cultural sites, ‘boundaries should be drawn to include all those areas and attributes which are a direct tangible expression of the outstanding universal value of the property, as well as those areas which in the light of future research possibilities offer potential to contribute to and enhance such understanding.’ The boundaries of the nominated property may coincide with one or more existing or proposed protected areas (such as, in the UK, conservation areas), but that will not always be appropriate. Wherever necessary for the proper conservation of the property, an adequate buffer zone should be provided. Clearly the implications of this in practice will vary considerably, according to the type of site. It seems that the sites inscribed on the list in the first few years of its existence did not have precise boundaries. That is no doubt being gradually rectified. Since 1995 it has not been possible for a site to be inscribed without a of human creative genius; (ii) exhibit an important interchange of human values, over a span of time or within a cultural area of the world, on developments in architecture or technology, monumental arts, townplanning or landscape design; (iii) bear a unique or at least exceptional testimony to a cultural tradition or to a civilisation which is living or which has disappeared; (iv) be an outstanding example of a type of building, architectural or technological ensemble or landscape which illustrates (a) significant stage(s) in human history; (v) be an outstanding example of a traditional human settlement, land-use or sea-use which is representative of a culture (or cultures), or human interaction with the environment especially when it has become vulnerable under the impact of irreversible change; (vi) be directly or tangible associated with events or living traditions, with ideas, or with beliefs, with artistic works of outstanding universal significance. (The committee considers that this criterion should preferably be used in conjunction with other criteria)… To be deemed of outstanding universal value, a property must also meet the conditions of integrity and/or authenticity and must have an adequate protection and management system to ensure its safeguarding.’ Following the annual meeting of the committee in July 2004, 611 cultural sites, 154 natural sites and 23 mixed sites had been identified in 134 nations.There is now strong emphasis on establishing a representative, balanced and credible list – in other words, the west European states whose sites are currently well represented will in future find it more difficult to have further sites inscribed. Procedure Article 11 of the convention requires each state party to select properties in its territory that conform to the above criteria, and submit an inventory of them to the World Heritage Committee. The committee will then produce and periodically update a list of all such properties which it considers as having outstanding universal value. The practical outworking of this is provided for in the Operational Guidelines. Where a state (in practice, the relevant department of the national government) Liverpool’s Albert Dock warehouses, part of the world heritage site, form the largest group of Grade l listed buildings in England. Designed by Jesse Hartley, they opened in 1846–47. Liverpool’sWilliam Brown Street Conservation Area now forms the city’s principal cultural quarter. Its northern edge is defined by the former County Sessions Court, theWalker Art Gallery, the Picton Library, the museum and the former College of Technology, comprising an exceptionally fine parade of civic buildings.
8 C O N T E X T 9 0 : J U LY 2 0 0 5 site – although that might of course be relevant in assessing the gravity of the offence. Inclusion of a site on a world heritage list is thus not of itself a further instrument of control. On the other hand, it should not be forgotten that not all world heritage sites are protected by existing designations – the Blaenavon Industrial Landscape site in South Wales and the Cornish Mining Industry tentative site in England, for example, are not fully protected; and although the Lake District is a national park, that does not provide full protection to the buildings within it. Development affecting a world heritage site Inscription of a site within the world heritage list highlights ‘the outstanding national and international importance of the site’ as a material consideration to be taken into account by a local planning authority or the secretary of state in determining an application for planning permission, listed building consent or scheduled monument consent. In particular, the Court of Appeal in the Bath Society case, back in 1991, held that where permission or consent is sought for development within a conservation area that is within a world heritage site, ‘the special attention which the inspector is bound to give to the provisions of [P(LBCA)A 1990, s72 (the duty to pay special attention to the desirability of preserving or enhancing a conservation area)] is of particular importance where the site concerned is of ‘such universal value that protecting it is the concern of all mankind’. This fact… requires at least that it must be manifest from the terms of the inspector’s report that very close consideration has been given to the provisions of this section, and it is insufficient that it is possible to spell out from the terms of the report that the inspector has, in some way, the terms of the section in mind.’ But it will be noted that this is stating that the fact that a property is within a world heritage site emphasises the importance of the conservation area duty. It does not introduce a free-standing duty of itself. A more recent decision of the courts considering in greater detail the importance of world heritage sites was Coal Contractors Ltd v Secretary of State, relating to Hadrian’sWall – scheduled as an ancient monument in 1982 and designated as a world heritage site in 1987. management plan having previously been prepared. Plans are still gradually being drawn up for sites inscribed prior to that date. Finally, theWorld Heritage Committee is to maintain a List ofWorld Heritage in Danger.This flags up cases where urgent action needs to be taken to avoid the deterioration of the condition of the property to the point where it might have to be removed from the world heritage list. There are currently 35 properties in this position (only two in Europe). World heritage sites in the UK The UK became a party to the convention in May 1984 (the 79th of the 180 countries which have done so to date). As at July 2004, a total of 26 sites within the UK had been inscribed on the world heritage list. And, as noted above, each state party is required to maintain a tentative list of sites which it intends to consider for nomination during the following years, and to resubmit it at least every ten years. The current position of tentative sites can be checked on the ICOMOS website (www.icomos-uk.org/whs). Relationship with other designations Of the sites within the UK that have been inscribed on the world heritage list, 20 are cultural sites, and a further 15 (including 12 cultural or joint sites) are on the tentative list. Some of the sites are extensive urban areas, where it remains to be seen whether the process will be subject to the same inflationary tendencies which have affected listing and scheduling. Cultural sites on the world heritage list – and indeed those on the tentative list – will by their nature in many cases be protected under UK domestic legislation.The specific buildings involved are generally listed buildings (many of Grade I or II*) or scheduled monuments; and most of the sites will be in conservation areas. It is these designations, and the associated policies, that will protect world heritage sites in practice. It is thus an offence to demolish a Georgian building in Bath because it is listed, not because it is in a world heritage The United Reformed Church at the world heritage site of Saltaire, a complete and well-preserved industrial village of the second half of the 19th century inWestYorkshire. Titus Salt built it to house the workers at his woollen mills.The mills, public buildings and workers’ housing are built in a harmonious style of high architectural standards and the urban plan survives intact, giving a vivid impression ofVictorian philanthropic paternalism. Cromford Mills, begun in 1771 by Richard Arkwright, include the world’s first successful waterpowered cotton spinning mill.They are now part of the DerwentValley Mills world heritage site. The complex, consisting of linked mills, warehouses and workshops, was saved from dereliction in the 1970s.
C O N T E X T 9 0 : J U LY 2 0 0 5 9 Charles Mynors and Alex Booth are barristers in the chambers of Robin Purchas QC in the Temple.This article is an edited version of the brand new chapter on ‘the international framework’, from the fourth edition of Charles’s seminal book, Listed Buildings, Conservation Areas and Monuments, to be published by Sweet & Maxwell later this year – to include all relevant new legislation and over 100 decisions of the courts since the previous edition. Permission was refused for opencast coal extraction within the setting of the wall. The applicant appealed. The inspector considered that among the main issues raised by the proposal was its impact on an area of great landscape value and on the setting of Hadrian’s Wall. He considered, however, that the applicant had complied with the need to avoid an adverse impact. However, the secretary of state disagreed with that recommendation, saying that a further issue must be the impact of the proposal on a world heritage site. That impact would be unacceptable, and the proposal should accordingly be rejected. The mineral operator challenged the secretary of state’s decision in the High Court, on the grounds that he had been perverse to distinguish the impact on the world heritage site as a separate issue. The deputy judge dismissed the challenge, drawing attention to the ministerial statement in the House of Lords noted above, and confirming that world heritage site designation was a material factor in planning decisions. The secretary of state had accepted that there was no demonstrable harm, but that did not mean that he had to accept every conclusion as to visual impact. He had elevated the world heritage site issue to be a main consideration, but that did not render his reasoning obscure or perverse. Further advice is given in central government policy on the formulation of planning policies relating to world heritage sites, and the scrutiny to be given to development proposals affecting them. But that is brief, and in the blandest terms. It is thus up to the relevant local planning authorities, and the secretary of state on appeal, to ensure the preservation and enhancement of world heritage sites through the normal development control process. It will in particular be essential for authorities to include within their local development frameworks suitable policies to ensure the protection of sites – particularly in cases where no formal protection is provided by means of other designations. The issues arising from this are the same as with the preparation of policies for the protection of conservation areas, considered DerwentValley Mills world heritage site contains a series of 18th- and 19th- century cotton mills, and an industrial landscape of high historical and technological interest. in this column in the previous issue (Context 89, May 2005, p10). Environmental assessment One specific way in which extra protection is given to world heritage sites is that those undertaking projects of any kind within them are subject to a more stringent requirement as to the submission of an assessment of their likely environmental impact than would apply elsewhere.This reflects the principle that a minor proposal in a highly sensitive location can be as significant, and thus as deserving of careful assessment, as a much more major one in a much less sensitive site. Thus the 1985 European directive on environmental impact assessment (EIA) requires that, in principle, all projects in the categories listed in Annex I (that is, really major ones such as motorways and large chemical plants) must be the subject of an impact assessment; whereas those in Annex II need only be the subject of an assessment if they fall within certain criteria, set out at Annex III. These include the environmental sensitivity of the areas likely to be affected by the project in question, having regard, in particular, to landscapes of historical, cultural or archaeological significance.This requirement has been transposed into UK domestic legislation in the form of a suite of regulations, relating to various categories of projects. The regulations that are come across most often are those relating to projects requiring planning permission. These provide that an environmental statement must be submitted along with the application in all cases involving Schedule 1 development (major projects) and, within a world heritage site or other sensitive area, for all Schedule 2 development likely to have a significant effect on the environment by virtue of factors such as its nature, size or location. Outside such sensitive areas, statements only have to be submitted for Schedule 2 development where it is on a significant scale (determined by reference to criteria appropriate to the category of development involved). More recently, a further European directive has been issued on the assessment of plans and programmes, which has been transposed into domestic legislation as the Environmental Assessment of Plans and Programmes Regulations 2004. These require that an environmental assessment is to be carried out as part of the preparation of more or less any land-use related plan or programme where it is likely to have significant environmental effects on, among other things, areas or landscapes that have a recognised national, European or international protection status. That would obviously include inscribed and tentative world heritage sites. The net result of all these provisions is that development plans and proposals (in the broadest sense of that term) within a world heritage site are likely to be much more carefully scrutinised than it might be elsewhere.
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C O N T E X T 9 0 : J U LY 2 0 0 5 11 ALISON HENRY New developments in insulated, breathing lime floors Insulated, breathing lime floors offer tremendous possibilities in providing a potential alternative to inappropriate damp proof treatments and flooring in historic buildings. Since hearing a presentation by Ian Pritchett of IJP Conservation at the Building Limes Forum about five years ago, I have become fascinated by the potential for combining lime with lightweight aggregates to make an insulated, breathing ‘limecrete’ floor which requires no damp proof membrane to prevent rising damp. Much work has been carried out by IJP Conservation and by Calch Ty-Mawr Lime to develop insulated limecrete for flooring, including for use with underfloor heating systems. Many insulating limecrete floors have now been successfully laid in old buildings by various contractors in all parts of the country. The system is increasingly being used in new build where a more ecological alternative to concrete is desired. However, in discussions with conservation colleagues in other local authorities, I get the impression that news of this technology has not reached the wider audience that would benefit from it. Rising damp is a common problem in traditional buildings with solid floors, often being exacerbated by the occupants’ choice of floor covering. Usually the chosen solutions – either lifting and relaying flagstones on a damp-proof membrane (dpm) or replacing with a concrete floor – simply divert moisture sideways into the walls, creating a damp problem there and triggering a sequence of remedial treatments comprising injection damp-proof course, re-plastering with waterproof render, or dry lining, and so on. The resultant harm to the character and performance of a historic building will be familiar to many. Often a dpm is inserted beneath the floor of an old building when underfloor heating is installed. This can result in dampness in the walls of a building that previously suffered from no perceptible damp problem either in its walls or floors. In many cases an alternative to installing conventional damp-proof membranes may be to construct an insulated, breathing lime floor. The principle of a breathing lime floor is simple. A base layer of loose-fill, coarse, non-permeable aggregate is laid on a compacted sub-base, usually simply bare earth with a layer of geotextile on top. As there are no fines in the aggregate, there are consequently no capillaries (or micro-pores), so the layer of aggregate is unable to draw water upward by suction or capillary rise (the normal means by which rising damp moves). It is therefore an effective barrier against rising damp. A slab of lime concrete, or limecrete, is laid over the loose-fill layer, using a layer of geotextile to prevent it slumping down into the loose fill (hessian could even be used for a more ecological alternative). The limecrete will allow moisture vapour to pass through it and evaporate. If underfloor heating is required, Laying a limecrete floor pipes are laid in a layer of lime screed on top of the limecrete. Flagstones or quarry tiles can be bedded in lime mortar to create the finished surface. As with any new floor, it is important to check the depth of the wall foundations before excavating to avoid the risk of undermining shallow footings. A basic limecrete is made simply by substituting hydraulic lime for cement in a normal concrete mix. An insulated limecrete is made by substituting the ballast (sand and gravel) in a basic limecrete with a lightweight, insulating aggregate. The two most common aggregates are lightweight expanded clay aggregate (leca) and hemp. Leca is the most widely used of these as it is much more readily available than hemp in the UK. Leca is made by injecting droplets of liquid clay into a kiln at temperatures in excess of 1000 degrees Celsius. This forces the moisture in the clay to turn to steam, expanding the clay and riddling it with countless tiny air bubbles, which are then encapsulated as the clay is fired. The resultant granular material is best described as clay Maltesers, without the chocolate coating. Leca is sold under a variety of trade names including Fibofill, Optiroc and Hydroleca. It is available in a range of different sizes from about 1mm to 20mm, so it is comparatively easy to blend different sizes to produce a well-graded aggregate. The hydraulic lime binder will be either an NHL 3.5 or an NHL 5 depending on the required strength of the limecrete. Early testing of sample cubes made with NHL 5, carried out at Oxford Brookes University, found that the mix achieved a compressive strength of 4.5N/mm2 after 28 days and continued to gradually gain strength. Subsequent testing has resulted in NHL 3.5 being most commonly used to make a floor slab that has adequate strength for normal domestic use, while maintaining breathability. The thickness of the various layers will depend on the thermal insulation required but is commonly 150mm to 200mm for the loose fill, 150mm for the limecrete slab and 50mm for the lime screed.
www.ihbc.org.ukRkJQdWJsaXNoZXIy MjgyMjA=