CHRIS WOOD
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Winning stone from local sources
New initiatives are finding ways of obtaining the compatible stone on which many sensitive conservation and development schemes depend.
Obtaining the appropriate stone for conserving historic buildings can be extremely difficult, but it is essential if repairs are to both perform and weather-in satisfactorily. Increasingly, new-build projects in historic areas require stone which is compatible with its neighbours. This usually points to using material from local quarries. Many of these no longer operate and reopening them is a fraught process. Nonetheless, a number of initiatives are currently trying to address the problem.
English Heritage has supported a number of applicants seeking to reopen former quarries to provide stone for repairing walls or roofs. Where planning permission is needed there are often strong objections from residents in the area and others for whom the quarry site now has a new importance. Former workings make excellent nature reserves and many are now designated as county wildlife sites or sites of special scientific interest. When the planning committee or inspector considers the issues, they find a welter of policies and guidance in support of nature and landscape conservation but very little in support of the interests of building conservation. Invariably one question always posed is whether there is a more appropriate site somewhere else.
The ODPM has been aware of this problem for some time. Its proposed replacement for Mineral Planning Guidance Note 1 is intended to tackle the issue. Mineral Planning Statement 1 has been circulated in draft form and is due to be issued this summer. Annexes have been prepared including Annex 4: Natural Building and Roofing Stone Provision. These are due to be sent out for consultation at the same time. It is expected that this annex will address the need to protect the most important sources of stone. Local authorities will be encouraged to identify existing and potential quarries, and include suitable policies within development plans so that the needs of building conservation can be considered equally alongside other conservation and environmental designations.
There is one obvious problem. What are the most important stones? Are they stones that were used to construct and roof buildings of international importance? Or are they the basic ingredients used in vernacular structures which create such rich local distinctiveness? This question and the need to create a national database of building stones were highlighted in the Symonds Report1, which is expected to inspire many of the recommendations in Annex 4. The answer will depend, no doubt, on quantity and quality. Some form of hierarchical criteria may need to be established. At present our knowledge about which
stones were used and how many there are in any given area is extremely thin, so last year English Heritage commissioned a pilot study (the Strategic Stone Study) to see how a national database could be devised.
Geologists from the British Geological Survey (BGS) and Building Research Establishment (BRE) studied all the quarries and stone buildings in two areas of the west Midlands. The surveys looked at sample areas in an effort to estimate usage and provide some indication of the condition of the buildings. The pilot areas were selected in order to study two distinctive stones: the white sandstones found in Shropshire and the Arden sandstone found in Worcestershire and Warwickshire. The Grinshill quarry near Shrewsbury still produces building stone, but there are no sources for the red. The results of this part of the study will provide some quantitative evidence of the importance of these stones and help to guide the mineral planning authorities when preparing their plans.
The second part of the study, using local volunteer geologists, local history groups, amenity organisations and South Shropshire's conservation officer, is about to begin. Funded by English Heritage, ODPM and English Nature, this work will focus on stone slates in a defined area of the county. The results of the whole study, to be published in early 2006, will provide a
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Linshaws. The evidence of former workings highlights that stone can only be won where it occurs and that our predecessors knew best where to look.
Geologists carrying out the Strategic Stone Survey
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References
1  ODPM (2004) Planning for the Supply of Natural Building and Roofing Stone in England and Wales
2  English Heritage (forthcoming) Identifying and Sourcing Stone for Historic Building Repair: Technical Advice Note
3  English Heritage/ Dept for Transport (forthcoming) Streets
for All
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Park Wood Quarry, showing the hand-crafted nature of temporary quarrying for stone slates. The quarry opened and closed in a few months.
Herefordshire Quarry, bucking the trend. There has been great support from locals for a community effort to win enough stone to roof Abbey Dore and also to provide income for local farmers following the foot and mouth epidemic.
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trusts in the Midlands and west of England have applied for a Heritage Lottery Fund grant to research and set up a series of geological trails in each county. These will focus on the geology and quarries, and relate them to the grand and vernacular structures in the area. The plan is to train volunteers to guide school parties and adult groups on the trails and within the sites.
Detailed technical information is also due to be produced shortly. The IHBC Technical Committee is publishing a Mineral Planning Guide for applicants proposing to open a small quarry. This was written by members of the Stone Roof Working Group (SRWG), a body which includes quarry operators, roofing contractors, planners and conservation officers.
English Heritage will be publishing its Technical Advice Note: Identifying and Sourcing Stone for Historic Building Repair1. This will set out the criteria for replacement, which should be based on matching petrography, chemistry and appearance. The note shows how this should be done and how to find a reasonably close match if original sources are no longer available. The SRWG is also producing a best practice guide for stone roofing which will be available this summer on www.stoneroof.org.uk/best.
Finally Streets for All3, the English Heritage guide which positively promotes the distinctiveness of our traditional streetscapes, emphasises just how much this derives from the use of stone. Much of this material may well have been sourced locally and used for paving, kerbing, flagging, walling and copings. Replacements or new material should be sourced from original quarries, particularly if the alleged objective of sustainability is also to be pursued.
Chris Wood is senior architect conservator at English Heritage and a member of the IHBC technical subcommittee.
model or template for others to follow. Ultimately, it is intended that all this information could be available on GIS and easily accessed. Using suitable volunteers, albeit with some financial support, is likely to be the only way of undertaking a national survey. Professionals may well prove to be too expensive for such a task.
There is clearly a great deal of enthusiasm among geologists to help identify and promote England's unique stone heritage. The Geoconservation Commission (a body within the Geological Society) has set up an embryo English Stone Forum, which was formally launched at a three-day conference in York in March. A steering group includes professional geologists, representatives of the stone industry, English Heritage, English Nature, the Scottish Stone Liaison Group (SSLG) and the Welsh Stone Forum. Much can be learned from the SSLG, which was established in 1997. Of course the Scots do have the significant advantage of being able to get direct access to politicians to enlist their support, something which is rarely possible south of the border.
Individual geological groups are also very active in promoting the importance of stone. Eight geological
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