Rise in airtight homes prompts increase in mechanical systems

More than nine out of 10 homes have insufficient ventilation to meet regulations, research has found.

The Building Services Research and Information Association (BSRIA) has revealed that 95% of homes it tested did not meet the requirements of the 2010 version of Part F of the Building Regulations, which covers ventilation.

New homes are becoming more airtight in response to tougher energy regulations and are relying more on mechanical ventilation to maintain indoor air quality.

Jon Bootland, director of the Good Homes Alliance (GHA), which published a report on the issue in February, said the industry was struggling to cope with this rapid shift in build techniques.

He said: “How many homes had mechanical ventilation systems until about three years ago? We don’t have the skills base to get this right.”

BSRIA found improperly installed ductwork was the biggest problem, followed by undersized or insufficient fans. Housebuilders need to produce a test certificate to demonstrate compliance with regulations. But BSRIA said the standard of testing was poor as few testers had suitable equipment.

The GHA also said it found problems with poor testing.

“Someone had a commissioning certificate where there wasn’t any power supply so the system couldn’t possibly have been working,” Bootland said.