Another big growth area will be bioenergy, where about 6 per cent of electricity will be generated from burning wood, straw and energy crops.

Former floorboards were used for walls, as was burnt wood from the old chimneybreast.

Until the 12th century people in London had burnt wood for fuel.

It is unclear if health and environment officials will fine those who flout the laws on burning wood.

These can be primary projects, such as replacing a gas-fired boiler with one burning wood pellets.