Zero-carbon shops and offices would cost up to 30% more than conventional buildings, according to a new report. Financial Times

The finding comes as ministers consider the possibility of a new green policy for commercial property.

The government is already insisting that all new homes must be zero-carbon by 2016.

It asked the Green Buildings Council, which represents an array of developers such as Arup and Land Securities, to assess the practicality of cutting carbon reductions in new commercial buildings.

The report said this was unlikely to be achieved purely through on-site renewable energy – for example through solar power or biomass plants.

However, net carbon emissions could be cut to zero through better energy efficiency and the production of renewable energy at off-site locations nearby. However, the report – commissioned by the Department for Communities and Local Government – admits that this would come at a cost.

A green office block or shopping centre that met the new criteria could have a premium over other buildings of anything from 5% to 30%.

The GBC also urged the implementation of a European law on green buildings as soon as possible. The Energy Performance in Buildings Directive does not have to be implemented by the UK until January 2009.