Oliver Rehm, managing director of Baufritz UK, was speaking at the Grand Designs Live Show in London to raise awareness among consumers looking to purchase eco-homes. Around 700 attended the seminar, which included Mr McCloud, consultant environment adviser Charles Secrett and Sunand Prasad, RIBA president elect.

Baufritz uses organically forested larch and spruce logged from sustainable European forests. Mr Rehm said: “Many of the building materials used for saving energy are actually very harmful to the environment and to the health of the people who have to live in, work or install such buildings. People should be careful when commissioning a building.”

Baufritz built a “carbon positive” house for the show which attracted more than 10,000 visitors. The house stores at least 50 tonnes more CO2 than is emitted during its manufacture, transportation and construction.