Honeywell and Dalkia have been chosen to audit the energy performance of London’s public buildings with a view to cutting the capital’s consumption by 25%.

The announcement was made by mayor Ken Livingstone, who said the two companies must guarantee energy and financial savings over several years, based on the upgrades they recommend.

Buildings will be audited in groups and a single contract set up to retrofit all of them together. This will allow for economies of scale and consideration of long-term strategies such as decentralised energy supplies to save energy and money, according to the Greater London Authority.

Honeywell will audit 22 buildings belonging to Transport for London, including its Covent Garden museum. The goal is to eventually audit all of TfL’s 50 buildings and 264 Tube stations.

Jim Bujold, Honeywell’s vice president for Europe, Middle East & Asia, said the programme could be a boost for building services designers because of the many retrofit upgrades expected around the capital and its boroughs.

As audit consultant, Honeywell could not recommend specific products, he said, but it could compete with other firms at the tender stage for retrofit work.

Dalkia is to audit 10 buildings each from the Metropolitan Police and the London Fire Brigade.

London’s move is part of a global programme called the C40/Clinton Climate Change Initiative, announced in New York last May. Sixteen cities including New York will be working with the world’s largest energy companies such as Honeywell, Dalkia, Johnson Controls, Siemens and Tran, and banks including ABN AMRO, Citi, Deutsche Bank, JPMorgan Chase, and UBS to retrofit public buildings.

Other cites in the first round of the programme are Bangkok, Berlin, Chicago, Houston, Johannesburg, Karachi, Melbourne, Mexico City, Mumbai, New York, Rome, Sao Paulo, Toronto and Tokyo.