The scheme will also give clients hard data to benchmark Mace against rival contractors when bidding for work.

Subcontractors are being told to record information about water, waste and diesel use. This will be fed into the Credit 360 Platform programme currently being used by clients like British Land.

Mace aims to use the information to build a database detailing its carbon footprint on building sites by the autumn.

This will allow clients to scrutinise its performance when bidding for future work in the UK.

A league table of energy efficiency will be published in October by the CRC.

There is also talk that firms face being being charged £12 per tonne of emissions from 2012, under proposals being looked at by Government.