English Heritage Stone Building Conservation Grey slates of the South Pennines Individual building stones Strategic stone study 1 Research 2 Publications

English Heritage Stone Building Conservation

• Grey slates of the South Pennines

• Individual building stones

• Strategic stone study

1 Research

2 Publications

and advice

2 Influencing

legislation

• Identifying and sourcing stone for historic building repair

• Stone slate roofing technical advice note

• Stone slate delphs – making a mineral planning application

• Symonds report

• Mineral Planning Statement 1

• Authenticity

Lias limestone inserted in a sandstone wall


Repair and conservation of stone buildings

• Authenticity

• Appearance

Indian sandstone roof – wrong colour, wrong format



• Authenticity

• Appearance

• Technical compatibility

Incompatible porosity sheds water into the surrounding stone



The first choice is stone from the original source

20 kilometres



Loss of stone sources

• Contraction of the industry

• Brownfield development

• Amenity development

• Environmental protection

National Park

National Park

20 kilometres

10000 square metres



National Park

National Park







20 kilometres

10000 square metres


National Park

National Park






• Develop a dialogue between English Heritage and Natural England to resolve the issues.

• Symonds report

Sourcing local stone

Mineral planning should include:

• A policy steer

• Emphasise the need for building and roofing stone

• Safeguarding of sources

• Promote a database of building and roofing stones and their sources

• Good mineral planning practice guide


• Symonds report

• Minerals Planning Statement 1


• Safeguarding


Mineral planning authorities should protect sources of stone needed for historic buildings.

English Heritage should advise which sources are important.

• Symonds report


• Stone study



Where did historic stones come from?

English Heritage Strategic Stone study

• Symonds report


• Stone study


Where did historic stones come from?

Research with British Geological Survey and local geological groups. At the end of the four year study the results will be available free online


Resource

• Symonds report

• Minerals Planning Statement 1 2006

• Stone study

• What is accessible?



Resource

Worked out

• Symonds report


• Stone study



Resource

Worked out

Residential buffer zones


• Symonds report


• Stone study



Resource

Worked out

Residential buffer zones Environmentally

protected

Accessible


• Symonds report


• Stone study



Resource

Worked out

Environmentally protected

Residential buffer zones

The potential availability of accessible stone is further limited by the willingness of the land and mineral owners to work the resource and of entrepreneurs to risk the cost of establishing production.


• Symonds report


• Stone study


• What is potentially available


• Are all stones equally important? Intrinsic value


• Technical importance is the extent to which a stone’s properties are special in terms of its suitability to be used. Strength, porosity, compatibility with the surround stone etc.

The ‘original’ stone would attract the highest ranking.



• Technical importance• Building importance.

Listing of historic buildings is a familiar ranking technique.

The higher the grade of the building the more important it would be to use an authentic stone for repairs and the higher ranking the stone would attract.

But vernacular buildings and other structures must also be accommodated.



• Technical importance• Building importance• Cultural importance

A stone may have a high cultural value even if it has only been used in one or a small number of architecturally or historically significant buildings.

A stone which has been used for all the buildings within a village is essential to its sense of place.



•Technical importance• Building importance• Cultural importance Other important cultural criteria include the contribution to

Local distinctivenessRegional character and continuity of useThematic useLandscape characterVillage and townscape detailing

Aggregating the rankings for technical, building and cultural importance will give the stone’s overall ranking – its relative intrinsic value.


• Is the demand for all stones equal? Market size


The market for an historic stone is

• proportional to the geographical extent and time span of its use

• plus the demand for new build

• but is inversely proportional to its durability


HERITAGE STONE1 Locally important2 Regionally important3 Nationally important

Intrinsic value

Accessibility and availability

HERITAGE QUARRYA Locally importantB Regionally importantC Nationally important

Market demand

- Extent of past use- New build- Durability

- Technical ranking- Building ranking- Cultural ranking

Comparison with other land designations

Safeguarding

Documents

English Heritage Stone Building Conservation Grey slates of the South Pennines Individual building stones Strategic stone study 1 Research 2 Publications