Gwynne Anthony 2020

ART506 Dissertation 2019. Anthony Gwynne . 39 Approved Document C C1 Site preparation and resistance to contaminants. C2 Resistance to moisture. 2004 edition incorporating 2010 Amendments (For use in Wales) Historic buildings Material change of use or alterations to existing buildings may include work on historic buildings. Historic buildings include: (a) listed buildings; (b) buildings situated in conservation areas; (c) buildings which are of architectural and historical interest and which are referred to as a material consideration in a local authority’s development plan; (d) buildings of architectural and historical interest within national parks, areas of outstanding natural beauty and world heritage sites. The need to conserve the special characteristics of such historic buildings needs to be recognised 1 . In such work, the aim should be to improve resistance to contaminants and moisture where it is practically possible, always provided that the work does not prejudice the character of the historic building or increase the risk of long-term deterioration to the building fabric or fittings. In arriving at an appropriate balance between historic building conservation and improving resistance to contaminants and moisture it would be appropriate to take into account the advice of the local planning authority’s conservation officer. Particular issues relating to work in historic buildings that warrant sympathetic treatment and where advice from others could therefore be beneficial include the following: (a) avoiding excessively intrusive gas protective measures; (b) ensuring that moisture ingress to the roof structure is limited and the roof can breathe 2 . Where it is not possible to provide dedicated ventilation to pitched roofs it is important to seal existing service penetrations in the ceiling and to provide draught proofing to any loft hatches. Any new loft insulation should be kept sufficiently clear of the eaves so that any adventitious ventilation is not reduced. In most cases the rate at which gas seeps into buildings, mainly through floors, can be reduced by edge located sumps or sub-floor vents. These are less intrusive than internal sumps or ducts that may involve taking up floors. If flagged floors are taken up the stones should be indexed and their layout recorded to facilitate relaying when work is completed 3 . Radon can be dispersed by ventilation strategies such as positive pressurisation. These systems can often be accommodated in an unobtrusive manner. If internal mechanical ventilation is used to disperse ground gases, it may affect the functioning of combustion appliances and may lead to the spillage of products of combustion into the building. Guidance on this can be found in Good Building Guide 25 Buildings and radon 4 .   Footnotes; 1. BS 7913:1998 Guide to the principles of the conservation of historic buildings. Provides guidance on the principles that should be applied when proposing work on historic buildings. 2. SPAB Information Sheet 4 The need for old buildings to ‘breathe’, 1986. 3. and 4 are omitted as not relevant to this dissertation Figure 12: Summary of guidance for historic buildings in Approved Document C (Source: www.gov.wales/buildingregulations-approved-documents) .