Energy and water consumption represent some of the largest operating costs in multifamily properties, estimated at $22 billion per year in the U.S. The total expenditures for both energy and water utilities for public and assisted housing in 2011 were estimated to be $7.1 billion, with the U.S. Department of Housing and Urban Development’s (HUD) share estimated to be $6.4 billion or nearly 13% of HUD’s total budget. A growing body of research shows that 25% or more of this energy and water is wasted through inefficiencies that could be corrected by the expansion of efficiency upgrade programs for multifamily housing. In studies that compare the cost of strategies to reduce greenhouse gas emissions, efficiency gains in buildings are considered to have a negative cost, because energy and water savings alone tend to more than offset the cost of upgrades. By improving energy and water efficiency, multifamily homes would not only use fewer resources, but would cost less to operate, improving affordability for residents and reducing operating costs for HUD and for private owners.
Despite this potential for savings, efficiency retrofits are less common in multifamily housing than in single-family housing. One barrier to increased activity in this sector is the limited quantity and reliability of data relating to multifamily retrofits and their potential impact on energy consumption and utility costs. This report will add to the available knowledge base by providing a detailed analysis of 236 multifamily properties that underwent energy and water retrofit projects from 2009 to 2012. This is the first study to examine a large and diverse national data set containing pre- and post-retrofit utility data for both owner- and tenant-paid energy and water accounts. In addition to the findings themselves, the challenges faced in performing this research provide useful insights for others seeking to understand and execute energy and water retrofits in multifamily properties.