As building owners and tenants become more aware of the benefits of sustainability, many are opting to sign green leases, either during the leasing process or as an addendum to an existing lease. The goal is to help both parties save money by reducing operating costs and reach building efficiency goals. According to a 2015 study by the Institute for Market Transformation, green leases have the potential to save the U.S. office market $3.3 billion annually and cut energy consumption by up to 22% in leased buildings. Sounds pretty compelling.