by Anthony Lymath
This is the first in an eight-part series of articles, Climate Change Adaptation in Buildings, examining the impact of climate change on the built environment, and the responses that can be made to those changes for both new-build and retro-fitting. Forthcoming articles will look at excess heat, flooding, subsidence, drought and wind.
More and more frequently in recent years, the perception that the Earth’s climate is altering has been growing in public consciousness. From the first talk of ‘greenhouse gases’ and the hole in the ozone layer, ‘global warming’ has been the catalyst for a sea-change in behaviour across the globe. More recently however, this watch-term has been subsumed by ‘climate change’, a more wide-ranging descriptor which acknowledges that rising temperatures aren’t the only meteorological concern. And regardless of whether or not you agree with the theory, the one thing that can’t be disagreed upon is that the majority of buildings are not well-suited to changes in weather patterns beyond a very narrow range. Over the last ten years Britain has been affected periodically by severe flooding, for example; and now reports are emerging in the national media of over-heating, particularly in modern housing. In part at least, this is a consequence of the initiatives to improve insulation and air-tightness levels (although the problem has been incubating over the last ten years or so, and is not of course limited to modern housing).
Regardless of whether or not you agree with the theory, the one thing that can’t be disagreed upon is that the majority of buildings are not well-suited to changes in weather patterns beyond a very narrow range. In response to this recognition, the UK government is now actively promoting the concept of adaptation to climate change1: in other words, how buildings can be designed to cope more satisfactorily with ‘extreme’ weather events. To this end, NBS has recently been working with the Environment Agency to improve the guidance in its specification tools, by including advice on adaptive measures that can be incorporated at the specification stage, whether for new construction work or alteration of existing. Whereas the guidance is aimed primarily at the specification of systems and products which can militate against the effects of climate change, advice has also been given where appropriate on matters for consideration at the earliest stages of design. The scope of this guidance has been limited to the United Kingdom (in harmony with NBS Building and NBS Create), and includes five key areas2 of climate change:
- Excess heat
Until recently, legislation and regulations have been limited largely to flood-related matters: Planning policy statement 25 in England and Wales, for example, sought to discourage building on floodplains without first undertaking a flood risk assessment, followed by setting minimum floor heights above predicted flood levels3. The subsequent replacement by the National Planning Policy Framework (NPPF) broadens the requirement for Local Planning Authorities (LPAs) to “adopt proactive strategies to mitigate and adapt to climate change, taking full account of flood risk, coastal change and water supply and demand considerations”4. As far as construction regulations are concerned, Scottish Building Standards, Technical Handbook 3.3 is the most direct, whereas Approved document C, H and J in the England and Wales Building Regulations contain only minor provisions for flood mitigation. Both the Northern Ireland and the Eire regulations do not (at the time of writing) make any reference. However, national and regional policies are now being developed and implemented specifically to deal with the anticipated climate change over the coming years. In England, the Climate Change Act 2008 sets targets for CO2 emissions reduction by 20505 (see also the Climate Change (Scotland) Act 20096). The Department of Energy and Climate Change (DECC) sets national policy to reduce emissions7, and the Department for Environment and Rural Affairs (Defra) are tasked with implementing domestic policy8 including the National Adaptation Programme (NAP)9. Many of these measures can result in visible features on a building, and as such should be discussed with the relevant LPA and, where relevant, conservation officers. Some measures, such as flood-resistant floor levels, may need to be balanced against other requirements such as accessibility.