Onsite power generation levels announced

Proposals for how much energy must be produced on site for new housing is being put out to consultation next week. The proposals are less than suggested by the last government which means if the proposals are adopted a greater proportion of offsite green energy will be allowed for new zero-carbon housing schemes.

The proposed levels, called “carbon compliance” have worked up by the Zero Carbon Hub. Carbon compliance is a measure of how much carbon emissions must be cut compared to 2006 Part L and includes fabric performance improvements and onsite low and zero-carbon technologies such as PV panels.

The last government proposed a carbon compliance level of 70% with the remaining 30% met using offsite measures called allowable solutions, which are yet to be defined. The Zero Carbon Hub has already defined what percentage of the carbon compliance figure must be met using improvements to the building fabric.

The Zero Carbon Hub suggests that carbon compliance is measured in terms of how much carbon dioxide is emitted per square metre per year. It proposes different levels for apartments and homes and suggests the carbon reduction targets for homes should be between 50%  and 64%. This is equivalent to carbon emission of between 8kgCO2/m²/yr and 12kgCO2/m²/yr.

For low-rise apartments the carbon reduction targets should be between 44%, which will be equivalent to the standards in 2013 Part L and 57%. This is equivalent to 10kgCO2/m²/yr and 14 kgCO2/m²/yr. The figure for apartments is less onerous than houses as the Zero Carbon Hub says the solutions should work for individual dwellings and this was harder to achieve for apartment blocks.

According to the Zero Carbon Hub, the figures are based on costs of between £300-£600 per kg of carbon saved per square metre per year. Once the industry has learned which solutions work the best this should reduce to between £100-£200kgCO2/m²/yr.

The Zero Carbon Hub is asking the industry where the carbon compliance levels should be within the proposed bands at a series of roadshows. These are being held in Manchester on 30 November, London on 1 December and Milton Keynes – 2 December.