Experts warn that buildings without air-conditioning will not cope with climate change by the year 2030.
Global warming could make nearly three-quarters of all commercial buildings in the UK unusable in summer by the year 2030, experts have warned.

Leading global warming expert Nick Cullen, at consultant Hoare Lea, made his shocking predictions to Building this week.

He said: "Seventy per cent of all business premises are naturally ventilated; by 2030 they will become unusable in summer."

Cullen has warned that climate change would force a fundamental rethink in low-energy building design.

He said that to keep temperatures within an acceptable range, many buildings designed to be naturally ventilated would need to be adapted to provide air-conditioning.

However, many of these buildings do not have the space to install air-conditioning systems. Cullen said that "such buildings will not have a future".

Geoff Levermore, professor of the built environment at University of Manchester Institute of Science and Technology, agreed with Cullen's predictions.

He said: "If you have hot days and hot nights you are not going to get much cooling from the air."

Levermore added: "There are going to be problems ahead and designers need to be thinking about the future in the buildings they design now."

These warnings on global climate change also have implications for many timber-frame and modular construction methods, because they do not use materials with sufficient thermal mass.

Heavyweight construction elements such as concrete floors, which have a high thermal mass, absorb heat during the day, keeping a building cool. This heat is released at night when the air temperature drops.

Architect Bill Dunster warned: "Climate change is the death of lightweight construction. It has not got a future in a country that will get increasingly uncomfortable in summer."

He added: "You don't tend to find many Mediterranean countries using lightweight construction."

The predictions call into question the government's drive for increased use of off-site manufacture in the construction industry.