PPS 6: Planning, Archaeology and The Built Heritage
Listed Buildings: Policy BH 8
Justification and Amplification
6.10 Many listed buildings can tolerate some degree of thoughtful alteration or extension to accommodate continuing or new uses. Indeed, cumulative changes reflecting the history of use and ownership have contributed to the special interest of some buildings. Nevertheless listed buildings do vary greatly in the extent to which they can accommodate change without loss of special interest. Some may be sensitive even to slight alterations, especially those buildings with important interiors and fittings. Some listed buildings are subject to successive applications for alteration or extension. In such cases it should be borne in mind that minor works of indifferent quality, which may seem individually of little significance, can cumulatively reduce a listed building’s special interest.
6.11 The Department will consider whether the works proposed would cause unnecessary damage to the historic structure, whether the additions are in keeping with other parts of the building and if any new internal or external features harmonise with their surroundings.
6.12 In judging the effect of any alteration or extension the Department will assess the elements that make up the special interest of the building in question. They may comprise not only the obvious visual features such as a decorative facade or, internally, staircases or decorated plaster ceilings, but also the spatial layout of the building, the archaeological or technological interest of the surviving structure and the use of materials. These elements are often as important in Northern Ireland’s simple vernacular buildings as in its grander architectural set pieces. All proposals for alteration should also be based on a proper understanding of the structure of the listed building, because it is vitally important that new work does not weaken the structural integrity of the building.
6.13 The listing grade of a building is not of itself a reliable indicator of it’s sensitivity to alteration or extension. Many Grade B buildings may have been specifically listed because they are relatively unaltered examples of a once common vernacular building type. Accordingly they can as readily have their special interest ruined by an inappropriate alteration or extension as can Grade A or B+ structures.
6.14 Where a building forms part of an architectural group, for example as part of a terrace, then it may not be possible to make even minor external alterations without disrupting the architectural unity of the group. Even painting or stone cleaning of only one unit in a terrace can have this effect.
6.15 The preservation of facades alone and the gutting and reconstruction of interiors, is rarely an acceptable approach to the re-use of listed buildings and will only be permitted in exceptional circumstances. Where this approach has been accepted in the past by the Department this has applied mainly in cases where historic buildings have sustained major damage unintentionally. By adopting a flexible and imaginative approach historic buildings can be adapted to new beneficial uses without destroying their architectural and/or structural integrity. For example, maximum office floor loadings are never needed in all parts of a building, so any unusually heavy loads can often be accommodated in stronger areas such as basements.
6.16 Further detailed guidance on alterations to listed buildings is given in Annex E. The Department would also draw attention to BS 7913:1998 which provides advice, information and guidance on the principles of the conservation of historic buildings.
6.17 The Department would encourage the Building Control sections of local councils to adopt a sympathetic approach when exercising their responsibilities under the Building Regulations with regard to the repair or conversion of listed buildings. The intentions of the Regulations can usually be achieved without the removal or mutilation of features which contribute to the character of a listed building and are part of the reason for it being listed. It will be necessary for a dialogue to exist between Building Control and the building owner, where the owner too is prepared to adapt his ideas in order to achieve a maximum of conservation and a minimum of destruction without the loss of safety.
The Needs of People with Disabilities
6.18 The Department recognises the importance of allowing people with disabilities dignified and easy access to and within listed buildings. If access requirements are treated in an integrated and systematic way, and a flexible and pragmatic approach is taken, then it is normally possible to plan suitable access for people with disabilities without compromising a listed building’s special interest. In the case of a disabled person living in a listed building, then the Department will be sympathetic to their special needs when considering applications for listed building consent.