Conservation Bulletin (69)

Editorial explaining the importance of repairing historic buildings with authentic materials in order to sustain their character, in turn supporting traditional industries and craft skills.

The process of matching stone for building conservation addresses the three questions of what type of stone the original fabric is, where it came from, and where matching stone can be sourced. These questions are discussed in the article and directions for future research are considered. LD

Discusses issues relating to the care of terracotta buildings, which have only fairly recently entered the conservation agenda '“ most buildings in England that incorporate the material date from the period 1860 to 1939, and have only now reached their first or second major overhaul. LD

Magnesian limestone is a soft, cream-coloured stone that was used to construct many of northern England's monumental medieval buildings. However, it is prone to severe decay in the form of fracturing, contour scaling and erosion. This article briefly describes a project undertaken by the Building Conservation and Research Team at English Heritage, the Getty Conservation Institute and Princeton University, which examined the causes of deterioration of the stone and tested potential treatments, focusing on the example of the ruined 14th century chapter house of Howden Minster in the East Riding of Yorkshire. LD

The preparation of the Mortars, Renders & Plasters volume of the new series on Practical Building Conservation provided an opportunity to review the development of policy and practice in this field over the last twenty-five years. One of several areas in which it was evident that best practice had evolved concerns the kind of mortar binder considered appropriate for different purposes; this is examined in the article, which outlines the differences between modern hydraulic lime and its historic counterpart. Another area where practice has evolved since the 1990s -- the blending of hydraulic and non-hydraulic lime -- is also discussed. LD

In recent decades it has become clearer that the critical factor in the deterioration of building materials and systems is the building environment. This article explains the need for effective environmental monitoring and the importance of understanding the part it can play in the overall process of building diagnosis. Two case studies are included, looking at the conservation of in situ window glass, and at how the causes of deterioration of a 15th century wall painting at Cleeve Abbey in Somerset were investigated. LD

English Heritage is concerned that ever more stringent targets to improve the energy performance of all dwellings may lead to inappropriate and potentially damaging work to traditionally constructed homes. A programme of research commissioned from Glasgow Caledonian University aims to address the current lack of evidence regarding the actual thermal performance of traditional buildings, using a combination of fieldwork, modelling and laboratory testing. The initial results from whole-house performance tests carried out before and after the refurbishment of a 19th century brick house in New Bolsover, Derbyshire, are discussed. LD

Case study outlining the process of sourcing stone for repairs to the Grade I Listed Baddesley House, a moated house near Warwick that dates back to the 13th century. LD

Concern over supply of thatching straw has been a topic of debate for decades, and in 2011 the National Thatching Straw Growers Association was formed with very clear aims to reverse the decline and apparent bias against thatching straw and to promote its benefits for thatching. This article explains some of the issues affecting thatch and thatching straw and describes a research programme, currently at the pilot phase, that will look at different wheat varieties, husbandry regimes and thatching techniques. LD

Organised crime has increasingly been targeting stone, copper and lead from buildings, with significant numbers of listed and non-listed historic buildings, including places of worship, being affected. The positive responses of police forces are beginning to reduce thefts in areas such as Lincolnshire and Durham. English Heritage has been working with various groups and bodies to communicate this positive message, and has been actively involved in preparing Impact Statements where prosecutions are in hand, to demonstrate to courts that these crimes are not 'victimless'. It is also working with partners to test better methods of fixing, marking and securing metals, so that theft is more difficult and ownership more obvious. LD

Castle Drogo, situated on a promontory overlooking Dartmoor, was designed by (Sir) Edwin Lutyens in 1910 and completed in 1930. It is built of granite, with comparatively modern asphalt roofing. The National Trust acquired the building in 1974, and when roofing repairs undertaken in the 1980s began to fail, commissioned a comprehensive investigation. From this it became clear that water ingress posed a significant threat throughout the castle. A modern roofing strategy was developed and employed, and an appropriate repair mortar for the chapel was selected and was monitored for three years to ensure that the repair strategy had been successful. The clear aesthetic improvement in the presentation of the chapel demonstrated that a technical and scientific response to the building's failings could be coupled with a return to the original design and the recovery of a great work of art. Repairs are now being extended to the remaining sections of the castle, following rigorous analysis and testing of materials and methodologies. LD

Outlines some potential risks that future climate change could bring to buildings in the UK, such as increased water run-off and the spread of introduced timber pests. For buildings constructed using traditional methods and materials, the direct impacts of altered weather patterns are likely to be small. Instead, ill-considered attempts at mitigation in the context of higher expectations from buildings and concern over carbon emissions could pose the greatest threat. The safest approach would be to focus on 'no-regrets' actions such as good maintenance rather than risky and carbon-costly interventions. LD

With 25% of the building stock constructed before 1919, the number and range of traditionally built structures in the UK is vast. The shortage of people with the appropriate conservation knowledge and craft skills to work on these buildings is therefore a critical issue. This article reports on work-based training opportunities that are being facilitated by a group of bodies comprising Cadw, ConstructionSkills [sic], English Heritage, the National Heritage Training Group and the National Trust. Two case studies are presented, looking at a placement at Manchester Town Hall and Library, and a heritage blacksmithing company set up by a former trainee. LD

Whilst many former quarries and hitherto unworked deposits are potentially available for the extraction of stone, many other sites cannot be accessed for a variety of reasons. In order to maintain supplies of traditional building stone it is important to protect viable sources from development that could prevent their future exploitation. This can be achieved through 'mineral safeguarding': the National Planning Policy Framework (NPPF) requires local authorities to define Mineral Safeguarding Areas and adopt appropriate policies so that they are properly considered in planning decisions. The process of identifying and defining such areas is outlined in this article. LD

Short item noting that data produced by English Heritage with the Association of Local Government Archaeological Officers (ALGAO) and the Institute of Historic Building Conservation (IHBC) continue to show a fall in the number of historic environment specialists providing advice to local authorities in England. This continues a downward trend that began in 2006 and has so far seen reductions of 16% and 31% in archaeological advice and conservation advice respectively. LD

The 2012 European Heritage Heads Forum (EHHF) meeting took place in Potsdam and Berlin in May. Under the title Public Engagement with Cultural Heritage, the meeting considered the joint role of active citizenship and governmental responsibility in the preservation of cultural heritage and the need to arouse public interest in the preservation of monuments, particularly among young people. The meeting critically examined the role EHHF can adopt in order to protect Europe's cultural heritage both now and in the future.

Highlights legal reforms currently being progressed by the government that will affect the treatment of Conservation Areas and Listed Buildings within the planning system. LD

Looks at two case studies where planning inspectors have made use of policies from the National Planning Policy Framework, published seven months previously, to justify the rejection of appeals against refusal of planning permission. From these it appears as though decision-makers have readily grasped that proposed development which unjustifiably harms heritage assets or fails to take available opportunities for improving the character of an area is not sustainable development. LD