UK - The first clear framework to help landlords and occupiers increase the environmental performance of existing buildings has been published, claims the UK's Better Building Partnership (BBP).

BBP, initiated by the London Climate Change Agency, believes its green lease framework has the necessary flexibility to cater for different property types and sizes, as well as different levels of knowledge within the sector.

Green leases have provoked contention among landlords and tenants, especially in relation to the allocation of costs for improvements.

But BBP's green leases working group concluded that the best way to achieve the necessary degree of flexibility was to provide principles and guidelines for a "collaborative partnership approach".

Peter Clarke, executive office at British Land and chairman of the Better Building Partnership, said: "It became clear to us that one-size-fits-all could not work and therefore the principles and guidelines are deliberately non prescriptive. Owners and occupiers can agree carbon, energy, waste and water reduction strategies which best fit with the circumstances of individual properties. Introducing a memorandum of understanding is a much faster route to reducing environmental impacts than waiting for an existing lease - many of which can be 15 years or longer - to come up for renewal."

The BBP is keeping the implementation of the guidance under review and hopes to publish further guidance in 2009.

Hermes Real Estate was the first major property owner to launch a standard form green lease in April and is in the support of the framework.

Keith Bugden, Hermes Real Estate, said: "These principles are the culmination of a tremendous amount of effort by all members of the BBP's green leases working group. The result is, I believe, a real step forward and should be welcomed by all sections of the property community as a practical tool with which to achieve significant progress in the area of owner/occupier engagement on sustainability issues."