Conservation

Conservation

• Cultural Heritage is so often more noticeable due to its decades of neglect than for the reasons it should be cherished.

Listed Buildings• Listed because they are judged to be "of special architectural or historic

interest".

• Approximately half a million listed buildings or structures, but this is estimated to be only about 5% of the nation's building stock.

• Listed solely on their architectural or historic merit.

• Not a 'preservation order' that stops all change. Means the building is special and changes must be assessed by the local authority, and for more important buildings by English Heritage or its equivalent.

• In England and Wales there are three main Grades - I, II* (known as two star), and II. In Scotland the grades are A, B, B (group), C. In Northern Ireland they are A, B+, B.

• Only about 3% of listed buildings are Grade I (the most important grade); a further 5% are II* (and therefore special in some way); while the remaining 92% are Grade II. The grade has nothing to do with the size or date of the building.

• All buildings built before 1700 which survive in anything like their original condition, most buildings (with some selection) between 1700 to 1840 are listed.

• After 1840 best examples of particular building types are listed: and only those of definite quality and character.

• Only selected buildings after 1914 are listed.

• Buildings less than 30 years old are normally onlylisted if they are outstanding, and under threat.

What is Listed?

• Listing covers the entire building, inside and out. Other structures within the curtilage of (land surrounding) the building may also be included.

• Anyone can apply for a building to be listed. You do not have to own the building.

• Write to English Heritage, 1 Waterhouse Square, 138-142 Holborn, London EC1N 2ST for buildings in England; or for Wales to Cadw,  Crown Building, Cathays Park, Cardiff CF10 3NQ.

Listed Buildings

• The local planning authority decides whether an application for consent is needed, and it is up to each local authority to decide whether your proposals will or will not "affect" the "character" of the building.

• PPG15: Planning and the Historic Environment which indicates the sorts of things that ought to require consent, such as the replacement of windows.

• May be forced to repair a listed building even if you can't afford the repairs but only if the building is decaying very badly. Local authorities have two main powers to halt the deterioration of a listed building - the serving of an urgent works notice or a repairs notice.

Listed Buildings

Conservation areas

• Designed to give some protection to local areas of interest, and usually contain some listed and some unlisted buildings.

• Designated by local authorities.

• Substantial demolition within a conservation area requires consent.

• Certain "permitted development rights" that apply to domestic buildings are reduced in conservation areas, so planning permission is needed for changes such as the installation of dormer windows on the front of a roof.

• Also need permission to lop or fell trees.

Scheduled ancient monuments

• Laws protecting scheduled ancient monuments are generally the most demanding.

• Many monuments are buried sites but some are standing structures, ruins, or unoccupied buildings.

• Almost any work to them requires the consent of the relevant Secretary of State.

• No powers to force the owner of a scheduledmonument to halt deterioration or carry out repairs, which is why a substantial number are at risk.

Items to Consider in Conservation

• An understanding of how these differences affect the issue of maintenance and in particular the choice of materials for repairs.

• A key point is to specify materials that are sympathetic to the building and compatible with its construction.

• Introducing new materials might have a negative impact on the performance of the building fabric. The use of impervious or waterproof materials, even as part of a diligent maintenance or repair programme, can potentially make problems worse rather than better.

• It is far better to try to retain the historic patina of an object by leaving ingrained dust, dirt and staining well alone.

Lime Mortar

• Use of Portland cement for repointing and render has caused, extensive spoiling of masonry, cracking, widespread problems of moisture trapped in walls owing to the failure of Portland cement joints and the inability of render to breath.

• Heat conservation, reduced maintenance, increased life of masonry materials and reduced energy consumption during manufacture are all benefits accruing from the use of lime mortars.

• Contractors become involved in work which, because of lack of knowledge, they underprice and fail to carry out effectively.

• Training, a system of suitable certification and the introduction of lime materials which are more user friendly.

Lime Mortar Repointing

Plaster Work• Gypsum plaster is viewed by many people in the conservation world

as a modern material which is inappropriate for use in historic buildings, yet it has been used in this country for hundreds of years.

• Clearly a role for gypsum plasters in conservation work,

• However modern bagged gypsum plasters are unsuitable for re-plastering ancient buildings. They are too hard and brittle to flex and move with the building, and most of them

will break down in the presence of moisture.

Roof Slates & Clay Roof Tiles

• It is important to obtain authentic material for historic repairs for both aesthetic and environmental reasons. Ideally, the same material should be sourced from the same quarry or from a nearby and geologically similar source and be correctly colour matched.

Slipped tiles or slates

• Not all colour changes, minor cracks or delamination mean that the roof is in poor repair, but debris on the ground from broken slates and tiles might indicate a problem.

• Missing or dislodged slates and tiles should therefore be reinstated before damage occurs to roof timbers or ceilings.

• Large areas of moss may also need to be removed as the moss can harbour moisture and cause slates and tiles to deteriorate more quickly.

• Ridge and hip tiles can become dislodged by high winds or stormy conditions so it is vital to check for missing sections, which should be replaced without delay.

Windows• Significant style changes implemented as a result of the Great Fire of

London and the building acts which followed in 1709 and 1774:

- 1) frames in the capital should be set back a minimum of four inches from the facade so that fire could not travel so easily from one window to the next. - 2) the boxes be set back behind the masonry. The result was that the sash boxes on either side of the sashes disappeared from exterior elevations, and the window openings became narrower and more elegant.

• A window produced in the 18th or 19th century can often be salvaged virtually intact and renovated to provide excellent standards of performance. As much as 95 per cent of the timber in an original window can be retained.

Plants• Plants may enhance the appearance of buildings, but shrubs, trees and

climbers such as ivy can damage walls or block gutters.

• If allowed to grow against the base of the wall this also tends to prevent the masonry drying out properly.

• Plant growth should be cleared away from the area around the base of the building and in particular from any ground gutters or drainage channels. The roots of plants and grasses can damage the integrity of such channels and impair their ability to carry water away from the building.

Conclusion

References

• All information contained in this presentation has been taken from:

• Institute of Historic Building Conservation. - http://www.ihbc.org.uk/

• Building Conservation.com - http://www.buildingconservation.com

• English Heritage - http://www.english-heritage.org.uk/