Building regulations govern all aspects of construction in the UK, but there is an increasing emphasis on energy efficiency and cutting carbon emissions from our homes.
The government first introduced energy conservation standards for new homes in England in building regulations as far back as 1972. Over the years, they’ve been steadily tightened, requiring insulation, modern windows and energy-efficient heating systems. The regulations today – set in Part L of the Building Regulations – cover both new homes and existing homes.
Building regulations for new homes use a carbon standard: we work out the likely carbon emissions from each new home using an official calculation methodology. Builders must ensure that the expected emissions are lower than the maximum target emissions rate (TER) allowed for that type of home. The target emissions rate has been tightened over the years, and – to meet it – builders may use renewable energy measures, particularly solar panels on the roof, in addition to energy saving measures in the home such as insulation.
Constructing to meet net zero standards
It’s vital that new homes are built to be as low carbon as possible. With the UK’s net zero carbon target for 2050 set in law, clearly the most cost-effective approach is to build today’s new homes so they can hit a carbon neutral standard, without the need for further retrofitting.
Unfortunately, a long standing policy to achieve zero carbon new homes by 2016 was abruptly dropped by David Cameron’s government in 2015. In fact, the energy and carbon standards in building regulations in England have not been tightened since 2013, despite the steadily growing public concern about climate change.
So it’s good that in the last eighteen months there’s been a new focus by the UK Government on this area. But despite a number of proposals, including a recent consultation on the Future Homes Standard for 2025, which would mean changes to Part L (energy) and Part F (ventilation) from 2020, we’re yet to see any pass into law. With a General Election looming, the fate of this consultation will be in the hands of whichever party forms the next government.
When you consider that over 165,000 new build homes were completed in 2018, and that the government is promoting large scale house building to meet a major housing shortage, this is a policy that will have huge impact on UK carbon budgets in the run-up to 2050.
The next step in building regulations – beyond the Future Homes Standard – is to take embodied carbon into account, that’s to say the emissions from manufacturing and transporting products. Research estimates put these embodied emissions at around 45% of a total building project.
A focus on embodied emissions in building regulations could see the market for recycled construction materials grow rapidly. Products such as glass mineral wool boast impressive credentials, as they use high proportions of recycled glass. And some of the greener alternatives to concrete include straw bales, rammed earth, bamboo, recycled plastic and wood.
The glass that goes into our windows is more problematic. Embodied emissions for standard float glass are greater than concrete – and even higher for toughened glass. Though glass can be recycled, the glass sheets used in buildings don’t tend to be currently.
It may be that using clean energy to generate glass eventually reduces its life cycle impact. There are currently a number of companies jostling to break electricity-generating glass panes into the mainstream. These use quantum technologies to produce glass that does it all: provides insulation, filters harmful radiation and makes use of the sun’s energy to provide power to a building.
Meeting housing demand while delivering to high standards of energy efficiency is no simple business – but the long-term potential savings do outweigh the costs. The construction industry will require clear regulations, practical guidance and appropriate training to fully utilise the most sustainable materials, whether they’re traditional or high-tech.