Database of State Incentives for Renewables & Efficiency®
https://www.energystar.gov/buildings/resources_audience/multifamily_housing
https://www.energystar.gov/buildings/resources_audience/multifamily_housing/industry_resources_and_reports
https://www.energy.gov/eere/buildings/take-action-save-energy-commercial-buildings
Energy Saving Checklist For Commercial Buildings