Historically, the Building Regulations – and thus building control – have focused on issues deemed relevant at the time. Over the years the regulations have been amended, rewritten and developed to suit the needs of society; and one of the main concerns today is climate change. How can building control help to manage its impacts?
For instance, the UK has experienced more extreme weather events in recent years, and these have damaged buildings and infrastructure. More frequent and intense winter storms have caused strong winds and heavy rain, resulting in both structural damage and flooding.
This has implications for building control. The design criteria for a building's ability to withstand wind are based on an estimate of the maximum wind loading to which it is likely to be subject over its life. This is a complex calculation that needs to take account of numerous factors, as well as the probability of the designed wind speed being exceeded during the life of the building.
To help with this calculation, building envelope designers and specifiers in the UK are advised to use a recognised code of practice. Until March 2010 this was BS 6399-2, which is still widely used, given people's familiarity with its contents. However, it has actually been replaced by BS EN 1991-1-4; this provides guidance on the basic wind velocity to allow for, as well as a wind location map from which the effect of altitude can be calculated.
As maximum wind speeds are on the increase the basic guidance may need to be revised, bearing in mind the safety requirements for exposed elements of buildings in these standards.
Regulating flood risk
Flooding is another climate change impact that causes extensive problems, and is of utmost concern to a significant proportion of the UK population. Although there have been many attempts to control flooding through the planning process, these have had varied degrees of success.
Control measures in the Building Regulations are very scant. Regulation C1 paragraph (3)(a) has a vague requirement restricting the passage of ground moisture to the interior of the building, but this does not refer to flooding in particular. Paragraph 0.8 of Approved Document C meanwhile mentions flood risk only to say it is not a currently a requirement of Schedule 1 of the regulations. It is incumbent on a building control officer, then, to take this guidance and exercise their control to mitigate the effects of flooding as they see fit.
This provision seems inadequate given that increased rainfall is resulting in buildings being flooded where previously they were not. Should the regulations therefore be amended to include flood measures for new-build properties, extensions and material changes of use? In addition, should any floodproofing or repair works be regulated to ensure they are of a suitable standard?
'Flooding is another climate change impact that causes extensive problems, and is of utmost concern to a significant proportion of the UK population'
Overheating and offsetting
Another important effect of climate change is the likelihood of hotter summers. With this in mind, some buildings may become overheated, prompting occupants to install air conditioning.
This amounts to a change of energy status as defined in the Building Regulations, and is therefore subject to building control. In such cases, part L of the regulations requires some form of 'consequential improvement' to the existing building, and Approved Documents 1B and 2B offer a range of acceptable measures.
But are these requirements sufficient to reduce overheating and carbon emissions? The effect of consequential improvements made under part L should be researched, so we can assess whether the regulations are achieving the intended results.
The world is changing: the climate is having a greater impact on the built environment than ever before. Building control has over the years adapted to numerous changes, and should continue to do so. To protect society from the effects of climate change, the Building Regulations need to evolve.
Martin Conlon FRICS is a former director at Assent Building Control and former chair of the RICS Building Control Professional Group Board
Contact Martin: Email
Related competencies include: Legal/regulatory compliance, Sustainability