The buildings include those owned by Transport for London including its headquarters in Broadway (pictured), the Metropolitan Police Authority and the London Fire and Emergency Planning Authority.
The contract is one of the first of a series of larger proposals to reduce the carbon emissions in thousands of offices, transportation buildings, police stations, hospitals and schools in the capital.
It forms part of the first stages of work to deliver on the agreement developed by the Clinton Climate Initiative (CCI) for the C40 group of cities at the New York Large Cities Climate Summit in May last year.
The CCI aims to cut carbon emissions in existing buildings by making them more energy efficient. London is the first city to complete the initial retrofitting of buildings. Paris and Houston are working on similar initiatives.
Under the terms of the contract, Honeywell and Dalkia will work towards reducing the carbon emissions in these properties by 25 per cent, over a period of time. The money saved via reduced energy usage will be used to fund investment in improvements such as insulation, energy efficient building management technology, and low carbon heating and cooling equipment.
This will help address the fact that the public building stock of London and other major cities is poorly insulated and uses older, less energy-efficient technologies to heat and cool them, the Greater London Authority said.
Speaking at the time of the announcement, Mayor of London Ken Livingstone said: “Today marks the start of the transformation of London’s buildings from the major source of carbon emissions in the city to a beacon of modern, low-carbon efficiency.
“As nearly three quarters of damaging carbon emissions come from energy use in buildings, improving energy efficiency is probably the single most important thing that we can do to cut carbon emissions.”