At a time when climate change is placing much attention on the construction sector for a multitude of reasons, the industry is having to make changes to mitigate the effects of climate change on the built environment and help decarbonise UK buildings.
One Norfolk-based construction business, which boasts a speciality in foundations and restricted access piling could be in line to benefit from these developments.
Subsidence is a well-known consequence of climate change on the built environment. While the incidence of subsidence can be dated back hundreds of years, climate change and the subsidence that it can inflict on buildings are a duo that is having a significant effect on construction today. To this end, the construction industry is having to make changes to both new-build and retrofitting practices to mitigate the impact of these.
Since the 1970s, when insurance policy clauses were introduced around the time of the 1976 heatwave, subsidence has been a key feature of building surveys and ground movements in the UK. Its causes can be swelling from excess ground water, or even shrinkage due to drought. The issue can also be aggravated by trees and the proximity of their roots to building foundations.
Human intervention is also a major cause of subsidence, particularly on old in-filled sites such as excavation workings where the fill can consolidate, degrade, or decompose over time. In addition, subsidence can also occur due to other problems, including cracked and broken drains or water supply pipes.
The NBS reports that shrinkage and swelling in England and Wales, where clay soils are commonplace, tends to occur within five metres of the ground surface. Although rarely more than 150 millimetres either horizontally or vertically, this is more than enough to cause significant damage and risk to safety. Non-cohesive soils like sands and gravels are also just as prone to causing subsidence, given their fine particles can be washed away during floods.
Among the solutions for avoiding subsidence are pre-empting where there is greater risk of it occurring, in order to try to avoid the issue entirely or minimise the risks. Where ground has a high risk of susceptibility to movement, and if the choice of location for the development is limited, then appropriate structural foundation options are recommended to mitigate against the risk of subsidence. Raft or piled foundations could be suitable options, or perhaps jet grouting depending on the circumstances and economics.
These sorts of activities, as well as carrying out underpinning in response to incidents of subsidence, fall under the array of expertise of DJE Construction, a Norfolk-based company which counts special foundations and restricted access piling for both private and commercial clients among its services.
Skilled in most aspects of foundation construction, DJE are not only well-versed in underpinning buildings afflicted by subsidence, but also jacking up builds that need to be returned to the appropriate level.
The business was formed in 1994 by David Evans, after he had gained experience from over 20 years of work in construction and piling and a university degree in the subject. David’s son, Richard, is also a major figure within the company and graduated university having read Mechanical Engineering. His extensive geotechnical and engineering experience has been instrumental in the recent growth and expansion of the business.
David Evans told The Parliamentary Review: “Alongside Richard and I are a team of experts in the business who have extensive knowledge and experience, including in-house civil, structural and geotechnical engineers, practically minded contracts managers and site operatives. Their expertise complements the transition from design to construction on site.”
While their wide-ranging expertise may render DJE Construction the ideal partner in addressing incidents of subsidence, the business is also well placed to cash in on the UK government’s drive toward more efficient foundation technologies, too.
The government’s Future Homes Standard earmarks heat pumps as part of the future of helping decarbonise households across the country. Put simply, a heat pump takes the available heat from the ground or air surrounding a property and increases it to a more useful temperature for use in the home.
Using freely available heat energy from the ground, heat pumps achieve higher efficiency than any other heating system and can reduce a property’s heating costs by roughly two-thirds compared to direct electric heating.
At present, the University of Southampton is undertaking research into heating and cooling energy required by buildings. Researchers say that 50 per cent of UK and EU energy consumption is taken up by space heating of buildings, excluding air conditioning. They believe that the answer to reducing the heating and cooling energy that buildings may lie within foundations, because the ground remains a relatively constant temperature throughout the year. This means that it is cooler than the outside air temperature in summer and warmer than it in winter.
Consequently, researchers say this temperature difference can be exploited by using a ground source heat pump system to extract or inject heat into the ground. All such systems require a heat exchanger to be constructed within the ground.
A recent innovation in this area is the use of building foundations and other underground structures in the function of heat exchangers as well as providing structural support to the overlying civil engineering structure. For these works to be carried out effectively, businesses with DJE Construction’s capabilities will need to be called upon.
And should the use of building foundations in the function of heat exchangers become part of the mainstream in decarbonising UK buildings, companies such as DJE Construction will be in light to benefit from consistent work as an ideal partner to carry out such activities.
What is for certain is that industry operators working in foundations will be watching these recent developments very closely indeed.
