India has ambitious renewable energy targets, a portion of which must be met through rooftop solar in residential buildings. Major Indian cities are seeing a trend towards gated apartment buildings (or apartment complexes). In these buildings, apartment residents share common areas that provide communal amenities. As such, the energy used in common areas is the aggregate use from all residents for the services. This working paper co-authored by WRI India and TIDE describes the findings from examining demand aggregation potential in ten apartment complexes in Bengaluru. We define demand aggregation as the act of grouping together multiple residents in an apartment complex as a single consumer of the services provided in a common area. The study found that there was significant potential to save energy in common services in apartment buildings and use solar energy to meet most needs. Apartment Owners Associations (AOAs) that manage common services can be the anchors for implementing these clean energy measures in apartment complexes.