New homes more affected by overheating, WSP:PB study says

A survey of 1,005 Londoners, conducted by ComRes for WSP:Parsons Brickerhoff, has found that summer overheating affected residents in newer homes significantly more than residents in older homes.

The survey revealed that 83% of Londoners suffered from uncomfortably hot homes this summer with only 13% of saying they never suffered from their home overheating.

But the percentage of respondents who experienced overheating ‘most of the time’ rose from 5% in properties built before 1967, to 13% in properties constructed between 1967 – 2002, and 19% in homes built in the past 13 years.

The survey also highlights the negative health implications to overheating with more than half (52%) of those whose home felt uncomfortably hot this summer reporting being woken up in the night, and almost a third (31%) saying they felt tired or unwell as a result.

David Bownass, building services director at WSP:Parsons Brinckerhoff, believes that higher levels of insulation in modern houses is causing them to overheat.

He commented: “Newer homes and flats are better insulated to cope with cold weather, but are consequently hotter in summer. There are a number of solutions available from; secure natural ventilation, external shading/shutters, clever window design and thermal mass in walls. In the future predicted warmer temperatures will force us to use air conditioning, so we should be designing buildings now to use, or at least allow affordable retrofitting of these systems.”

Barny Evans, an energy and sustainability expert at WSP:Parsons Brinckerhoff, thinks that building regulation need to change to adapt to London rising temperatures: “Avoiding overheating is becoming as important to some people’s health in southern cities as beating the cold, and Londoners will continue to suffer from gradually increasing outside temperatures whilst being ever more likely to live in hotter new homes or flats.

“It’s startling that already 8% of those suffering from overheating have had to install their own air conditioning. 72% opened their windows to cope but in the future this won’t help and isn’t always an option. If building design and regulations aren’t changed now the impact on health will worsen, productivity will reduce, energy consumption will increase, and the long term value of homes will be affected.

Earlier this year research carried out by Cartwright Pickard Architects and the Mackintosh Environmental Architectural Research Unit (MEARU) at Glasgow School of Art, also highlighted overheating in new-built homes as a growing issue.

The research, which monitored the performance of 20 new-build housing association homes built to Code for Sustainable Homes levels 3 and 4, found that in summer, excessive solar gain from unprotected full-height windows, along with underperforming ventilation systems and MVHR systems with non-functioning summer bypass functions, was contributing to overheating.