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Aug 06 2015

Building for our future climate

Sustainable ConstructionUK infrastructure has suffered severe disruption in recent years, from rail disruption caused by the hottest day since 2006 to flooding and storm damage during the winter of 2013/14.  This raises the question – how well prepared are we for future climate?

 

Weather vs Climate:

An important distinction to make when discussing this topic is the difference between weather and climate.  Climate refers to the long term trends, average rainfall and temperature, predominant wind directions and average ocean temperatures, whilst weather is the day to day effects we experience (such as the hottest day of the year). Weather is a symptom of climate. For the UK, predictions are that over the next 50-100 years we will experience warmer, drier summers and warmer, hotter winters with more frequent extreme weather events.

 

The Variables:

The two main factors affecting the built environment are rainfall and temperature, with humidity and wind as secondary factors. For coastal regions wind may be a greater concern, as is sea level rise.  Extreme weather events such as flooding, heatwaves and gales are just large changes in one or more of these variables.

 

Temperature

For building designers and operators, temperature concerns are about keeping its users warm enough during winter and cool enough during summer.  Cold or hot internal temperatures can have a significant impact on the health and comfort of occupants, and in commercial properties also affect productivity (a NASA study suggests a 3.6% fall in productivity for every degree increase over 22C).

As the UK climate warms, a difficult balance will need to be struck between maintaining high levels of insulation, to provide warmth during cold spells and reduce dependence on expensive heating, without adding to the challenge of summer cooling.

Cooling methods for the built environment can be divided into active and passive.  Active methods embrace a variety of air conditioning and climate control methods while passive cooling focuses on shading, ventilation, insulation and thermal mass for buildings, and green and blue spaces (vegetation and water) for the wider built environment.

Many existing buildings already perform badly in summer and will need extensive modification to continue to be habitable throughout the 21st Century.  In some cases, modification will be so extensive that replacement is a more viable option.  Structures with low mass and lots of glazing lsuch as the popular urban conservatory are likely to become uninhabitable in summer by the second half of the century.

 

Rainfall

At Risk InfrastructureGreater variations in rainfall pose a number of challenges for both individual buildings and the built environment from flooding and subsidence, to water management challenges.

Wet winters and drier summers can lead to soil contraction, particularly in clay areas demanding deeper foundations and underpinning works.  Wetter winters also increase the demands on drainage systems.  An increase in extreme weather events is likely to correlate to increased flooding within at risk areas. In addition to a requirement for major flood defence infrastructure works, building specifications will have to take into account higher groundwater levels in at risk areas, possibly changing how basements are used.

Water conservation will increasingly become a concern as summers become drier, particularly in the South East which has the highest population density and lowest rainfall in the UK.  One of the innovations that is likely to become common to meet this challenge is rainfall to greywater systems, which use rainwater that would otherwise end up in the drain for non-potable tasks like flushing toilets.

 

Wind and waves

The effect of climate change on average wind speeds and the resultant wind loading is poorly understood.  However a rise in extreme weather events means that increased structural strength of buildings will be a concern, particularly for assets situated in exposed coastal areas.

The combination of increasing frequency of storm events and rising sea levels means that many coastal areas will see a significant increase in flood risk and hydraulic damage (such as that suffered by the South West Mainline in 2014).  This will require significant investment in coastal defence infrastructure, and in many locations it may be more viable to relocate people and assets, letting the sea encroach rather than protect them.

 

Future Proofing our Built Environment

As the climate changes, new standards in design and materials will almost certainly be developed and information from environmental models will become increasingly important in designing for the future.

There is an opportunity to show innovation in the design phase by using information management methodologies such as BIM to incorporate and communicate this information seamlessly across project teams.

This would result in scenarios where a structural engineer, for example, would be able to look at a building model, compare predicted rainfall and wind speed changes against the building’s operational lifespan and make accurate design and materials decisions based on this information.

This kind of innovation and standardisation in materials, information and process will be necessary to future proofing our built environment and doing so in a cost effective way that the economy can bare.

 

Other post you may be interested in:

Building a modular future

Using technology to achieve BREEAM, LEED and Green Star accreditation

About the author

Michelle Mason

Michelle Mason leads the UK and MEAP Marketing team, with far too many years in B2B marketing to mention. A CONJECT newbie, Michelle is eagerly climbing a steep learning curve.

View my LinkedIn profile:
http://uk.linkedin.com/in/michellemason04

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