Major landlords and the City of Sydney will today sign a deal to cut carbon emissions and improve the sustainability of buildings in the nation's largest CBD.

The Sydney Better Buildings Partnership (BBP) is an alliance of the City of Sydney and 13 major organisations, which collectively own nearly 60 per cent of Sydney's CBD office space.

Lord Mayor Clover Moore MP said it's the first time major property owners in Australia have come together to develop energy, water and waste systems to improve environmental performance precinct-wide.

"Sydney is the most power hungry geographical area in the country and buildings produce nearly a quarter of Australia's greenhouse gas emissions, so buildings that use less energy and water and produce less waste will help in the fight against climate change," the Lord Mayor said.

"Producing energy locally instead of bringing it in from the Hunter Valley reduces pressure on the state's ailing electricity infrastructure and future electricity price rises across the State.

"Today's historic partnership will help Sydney businesses reduce their overheads, create opportunities for new businesses and make our city a better place to liveand work.

Foundation members will today sign a memorandum of understanding with the City of Sydney to reduce carbon emissions from their buildings, helping the City cut 70 per cent of carbon emissions by 2030 (on 2006 levels).

Chair of the Partnership and GPT Group sustainability manager, Bruce Precious, said, "The Better Buildings Partnership provides an exciting and unique opportunity for collaboration to cut greenhouse emissions arising from the social and economic activity across the City of Sydney.

"This critical mass of public and private property owners has the capacity to guide, as well as make, the important decisions needed to reach a low carbon,sustainable city."

The 14 founding member companies and organisations are AMP Capital Investors, Brookfield Office Properties Australia, Charter Hall, Colonial First State Property Global Asset Management, DEXUS, GPT Group, Investa Property Group, Lend Lease, Mirvac, Stockland, Frasers Property, the University of Sydney, the University of Technology Sydney and the City of Sydney.

Collectively, the organisations own 58 per cent of commercial office floor space in the Sydney CBD.

The BBP members have impressive environmental achievements and a number lead their sector on the Dow Jones Sustainability Index of the world's most sustainable companies.

They are constructing and retrofitting buildings that have set new standards for sustainability through innovative design and management practices, and use of advanced technologies and materials.