Summer danger of ‘red hot’ eco-homes

ECO-homes risk roasting residents by overheating in summer, researchers warned yesterday.

The low energy homes – billed as a solution to rising fuel costs – can heat up to more than 25C (77F) for days at a time.

Heavy insulation used to keep the buildings warm in winter also traps heat in summer – potentially putting vulnerable residents at risk.

Researchers from Coventry University tracked temperatures inside eco-homes over three summers and found 72 per cent failed their design criteria.

The study was conducted at a housing association in the city, where flats were fitted to German Passivhaus – or ‘passive house’ – standards, meaning they have very low energy consumption.

It found heat built up inside the homes faster than ventilation could remove it, leaving residents facing uncomfortable temperatures. One of them, Emma Taylor, 33, told the Sunday Times: ‘Last summer was a nightmare. I was pregnant and the

‘Risk of overheating’

flat was red hot.’ Passive homes can cut heating bills by up to 90 per cent, but there have been repeated warnings about the dangers of overheating. They have proven so efficient that even the heat from a plasma television can affect temperatures inside.

A separate study by Cardiff University found temperatures inside such houses would exceed 25C for five to ten per cent of the year in London – and could exceed 28C (82F) from 2050 if our climate warms up as predicted.

Britain has relatively few ecohomes, but building regulations mean all new homes must meet tough energy consumption standards from 2020. Architect Lynne Sullivan, a member of the Passivhaus Trust, said: ‘There is a danger of overheating in all homes built to the new regulations, particularly flats, and we have been warning the Government.’

The Building Research Establishment said it had launched a project to examine overheating.