The Building Conservation Directory 2021

USEFUL INFORMAT ION 6 171 C AT H E D R A L COMMU N I C AT I O N S T H E B U I L D I N G CON S E R VAT I ON D I R E C TO R Y 2 0 2 1 where exemptions or special considerations apply. Similar regulations are applicable in Scotland, Wales and Northern Ireland. The special considerations are described in Section 3.9: When undertaking work on or in connection with a building that falls in one of the classes listed above [3.7 and 3.8], the aim should be to improve the energy efficiency as far as reasonably practical. The work should not prejudice the character of the host building or increase the risk of long-term deterioration of the building fabric or fitting. The Approved Document recognises that any work on buildings which alters their fabric requires care and attention to detail. Consequently, it is important that guidance is provided and that those involved both in specifying and undertaking the work are appropriately trained and qualified. These needs were emphasised in the Each Home Counts report and from these recommendations the UK Government has supported the development of a series of Publicly Available Specifications (PAS). These are documents produced in consultation with the British Standards Institution (BSI) which define standards for good practice, products, services or processes. They include Retrofitting dwellings for improved energy efficiency. Specification and guidance ( PAS 2035/2030), Certification of energy efficiency measure installation in existing buildings and insulation in residential park homes ( PAS 2031) and, still in preparation, Retrofit of Commercial Buildings (PAS 2038). Currently retrofitting energy efficiency measures focus on improving the insulation of the roof and walls, restricting moisture and reducing draughts from windows and fireplaces. While these actions may be appropriate for some buildings, they do not necessarily consider the specific needs of traditionally built properties. The fear is that those involved in the specification and installation of energy efficiency measures will not understand traditional buildings which will result in unintended consequences for the building fabric and the occupants. What is required is a good awareness of what can and cannot be done when juggling the competing demands of energy efficiency improvement with the need to maintain the character of these buildings or increasing the chance of damaging their fabric or fittings. Traditional buildings need procedures in place which ensures that those involved in their energy efficiency improvement have a good understanding of the significance of the building and of the technical issues and challenges involved. Fortunately, this is covered in BSI standard BS 7913: 2013 Guide to the conservation of historic buildings drafted by BSI Committee B/560 which also monitor the development of the PAS 2030 series. BS 7913 describes best practice in the management and treatment of historic buildings and is applicable to historic buildings and traditional buildings with and without statutory protection. It provides little detail on energy efficiency measures, but it does outline essential guidance on assessing the significance of a building and on decision making in relation to the technical issues encountered in traditional buildings. Overall traditional buildings need a holistic approach which looks to improve the energy efficiency of the existing fabric of the building rather than retrofitting something new. For example, dealing with a moisture problem by allowing the fabric to breathe rather than by trying to stop moisture entering with a barrier, which can trap moisture inside. The challenge for BSI Committee B/560 is to embed the processes found in BS 7913 within the PAS 2030 series and in the training of those required to assess and improve the energy efficiency of traditional buildings. It is now firmly acknowledged that climate change is a real threat and that urgent and immediate action is required. It is the task of those involved in the provision of guidance to steer a course which addresses the emission of greenhouse gases while conserving the buildings which form such a key part of our built environment and heritage. In the future our descendants may well look back and wonder why we were so slow to reduce greenhouse gas emissions but let us hope that they do not also wonder why so few traditional buildings remain in good condition. Recommended Reading Svante Arrhenius, ‘On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground’, Philosophical Magazine and Journal of Science, Series 5, Volume 41, pages 237–276, April 1896 Bonfield, Peter, Each Home Counts , DCLG, December 2016, http://bc-url.com/bonfield HMSO, Report of the Committee appointed by the President of the local Government Board and the Secretary for Scotland to consider questions of building construction in connection with the provision of dwellings for the working classes in England, Wales and Scotland and report upon the methods of securing economy and dispatch in the provision of such dwellings , London: Cd 9191, 1918 PAS 2030/2035, Retrofitting dwellings for improved energy efficiency. Specification and guidance , BSI, 2019 PAS 2031, Certification of energy efficiency measure installation in existing buildings and insulation in residential park homes ., BSI, 2019 PAS 2038 (in draft): Retrofit of Commercial Buildings, BSI Knock it down or do it up? Plimmer, F et al, – www.brebookshop.com/details. jsp?id=321561, 2008 Sustainable refurbishment of Victorian housing , Yates, TJS, www.brebookshop.com/ details.jsp?id=286929, 2006 Approved Document L1B: conservation of fuel and power in existing dwellings , 2010 edition www.eci.ox.ac.uk/research/energy/ downloads/40house/40house.pdf TIM YATES is Technical Director of Building Research Establishment Ltd (see page 34) and Chair of BSI Committee B/560 Conservation of tangible cultural heritage. (Image: UK Green Buildings Council, www.ukgbc.org/climate-change ) The Bonfield review