This research on energy efficiency and occupant behavior in multi-tenanted buildings provides valuable insights into the challenges that confront the goal of achieving a 50% energy reduction in commercial buildings in the Greater Philadelphia region by 2014 (gpichub.org). Our research questions are grounded in a framework that investigates both direct and in- direct effects on energy use taking into account such factors as developer/owner requirements, building design and systems, construction outcomes, and building operator and occupant behavior. Research design and methods are drawn from the tradition of post occupancy evaluation (POE) research and entail both primary and secondary data collection via semi- structured interviews of tenants and members of the developer/owner team, an occupant survey, building walk-throughs, focus groups, utility bill and building automation system sensor log analyses, and building performance benchmarking.

Probably the most obvious conclusion we can of- fer is that multi-tenanted buildings are complex. All too often buildings (and their occupants) are treated as a black box, as if the organization of tenants within made no difference. Multi-tenanted commercial office buildings house tenants with diverse business objec- tives and, often, diverse energy needs. Moreover, the manner in which the occupants of multi-tenanted buildings interact with building systems and design may be influenced by their workplace objectives, in addition to work styles and personal preferences for comfort. While good building design and operation can help to mitigate these challenges, additional fac- tors such as fragmented responsibilities/ locus of con- trol issues, split incentives along with inadequate flow of information, and other related issues such as a lack of coordination between building design and interior design each may be especially relevant to a multi- tenanted context, given its heterogeneous population. These factors make can make energy management in multi-tenanted buildings highly challenging and helps explain shortfalls in realization of building perfor- mance objectives. Conversely, successful resolution of these factors could lead to joint benefits for building developer/owners and tenants/occupants. The devel- oper/owner of the two buildings comprising this study has instituted an energy efficiency objective to reduce energy consumption by 23% across its portfolio by 2012. The challenges of reaching this objective, as il- lustrated in this report, are informative for the GPIC mission of obtaining approximately double the reduc- tion in energy consumption in a slightly longer time frame.