Gwynne Anthony 2020

ART506 Dissertation 2019. Anthony Gwynne . 92 on internal wall surfaces hazardous to occupant’s health. It has also caused the collapse of cob walling illustrated in case study 5 and Figures 37, 38 and 39 . 8.2 The Problem (i) This study has found discourse within the construction industry that government policy on sustainability of traditional, historic and listed buildings is dominated by a positivist, neo-liberal agenda underpinned by a utopian belief in technological progress and power of the market . (ii) Approved Documents to the Building Regulations do not provide practical guidance for traditional buildings built with solid walls or vapour permeable construction and advice is very limited for historic and listed buildings. (iii) The Welsh Government have said they have already made changes to improve guidance in the Approved Documents and they are unlikely to make any more unless there is good reason. (iv) Non-vapour permeable applications are being inappropriately applied to traditional forms of vapour permeable construction with disastrous results. (v) Current U-value calculations underestimate the actual thermal performance of traditional solid walls. (vi) Current U-value requirements for upgrading traditional buildings are unrealistic and problematic as it traps water and increases the risk of condensation and mould growth. Wall areas behind internally applied insulation becomes a cold bridge and compounds this problem. The current U-value of 0.3 for upgrading existing solid walls should revised to 0.7 to reduce these risks. (vii) If Government revisions for Approved Document L improves U-value requirements for traditional buildings, the thickness of insulation required will be technically difficult to achieve if using appropriate vapour permeable solutions and there is concern that without guidance, thinner inappropriate non- permeable insulation would be used with disastrous results.