There is no sanctioned definition for what makes a lease a “green” lease. The term simply refers to a lease that has provisions addressing the energy efficiency and sustainability programs of a landlord or tenant. Green leases are certainly not mainstream, at least not yet; however, with landlords in California (and other states I hear) now required to benchmark their buildings and disclose energy use, the efficiency of buildings and the incentives landlords and tenants have to improve efficiency may be revisited, and more traditional green lease concepts will likely become part of standard lease provisions.
For more information, several excellent resources are listed below. Of all of these, I found the Retail Green Lease Primer, published by RILA/IMT, to be the most immediately useful because it provides an overview of the issues that may be addressed in a green lease and potential modifications that could be made to a lease to address each issue. You’ll want to make sure you download a copy of this two page primer and save it for future reference.
The Green Lease Library is part of the U.S. Department of Energy Better Buildings Alliance and has some of the most readily usable information related to green leases. The library also acts as an aggregator for resources from other organizations.
The Rocky Mountain Institute has several links to tools and resources for improving building efficiency, which is available here: www.rmi.org/tools_and_resources
Notably, the RMI partnered with BOMA to provide the RMI-BOMA Landlord-Tenant Sustainability Collaboration Guide, which is available here: www.rmi.org/Knowledge-Center/Library/2012-05_GuideForLandlordsTenants
And finally, the U.S. Department of Energy Better Buildings Alliance, which is the sort of mothership of all resources green. If you start here, you'll find most of the other resources listed here or elsewhere. Here are a two key links to start with:
Implement a green or energy-aligned lease. Green leasing is a general term that refers to any strategy that uses a lease to formalize the responsibilities between tenants and landlords with respect to a building’s green measures and practices. Also known as energy-aligned leases, high-performance leases, or energy-efficient leases, these approaches align the financial and energy incentives of building owners and tenants so they can work together to save money, conserve resources, and ensure the efficient operation of buildings. Green leasing is one tool that can be used to overcome the “split incentive” barrier to energy efficiency in commercial buildings.
Engage tenants to help improve the energy efficiency of their leased space. Roughly one-third to one-half of the energy consumption in commercial, multi-tenanted buildings is driven by the behavior, equipment, and operating decisions of the tenants. Landlords (owners and managers) seeking to improve the energy performance of their buildings need to encourage and work with tenants to adopt best practices for energy management.
If there are any high quality resources I've missed, please let me know and I'll add them to the list.