We must balance noise and overheating in urban housing

Both heat and high levels of noise in the home can have a negative effect on people’s health, such as dehydration and interrupted sleep. With air-conditioning rare in UK homes, the majority of us rely on natural ventilation to maintain comfortable temperatures and limit overheating, particularly during strong heat waves like we’ve experienced this summer.

Planning authorities must develop guidelines that require both noise and overheating solutions to be designed in tandem

Noise and overheating are considered separately in the design and planning stages. Planning guidelines do not mitigate against the two elements potentially being incompatible with each other. Research by Apex Acoustics analysed 160 planning applications for recent major new residential developments in London and for 122 of those, both noise and overheating assessments had been completed. They found in 85% of cases, the noise assessment was carried out assuming that windows would be closed but the overheating assessment was conducted assuming windows would be open.

The reality is a trade-off between two essential parameters for a healthy and comfortable living environment. It is unethical and unreasonable to design new buildings for people to live in noisy conditions for this amount of time.

Planning authorities must develop clear guidelines that require both noise and overheating solutions to be designed in tandem. This will assure future occupants that their wellbeing is a key consideration, help designers advise their clients on measures to include and ensure that new developments do not fall down at the planning stage. One solution would be to revisit Part L of the building regulations, specifically the fabric energy efficiency requirement that currently favours passive solar gains to help reduce heating energy use in the winter. In the summer, this can lead to unintended consequences, with homes heating up too much.

To solve this, Part L could be changed to increase the consideration of cooling energy and overheating compared with heating energy. This could be improved by lowering the g-value of the glazing in the notional building to be more in line with high performance double glazing.

Fundamentally, designers should first implement measures to reduce developments’ risk of overheating as far as possible, for example by optimising glazing and applying external shading to reduce solar gain.

Developing clear planning guidance so that both are applied together will be critical, as well as revising the building regulations to reduce the risks of overheating.

Katherine Holden is an executive engineer at Sweco