Commercial buildings generate about 16 percent of energy-related CO2 emissions in the United States and about half of the total emissions from the building sector. Furthermore, direct fossil fuel combustion in commercial buildings alone accounts for 5 percent of total energy-related CO2 emissions in the country.

Given that most commercial properties are large — over 80 percent of commercial floor space in the United States is in buildings larger than 10,000 square feet — and are more likely to be owned as part of a portfolio, there is an enormous opportunity to replicate and scale solutions for commercial electrification and ultimately to have an outsized impact in the building sector’s transition toward a clean, carbon-free future.

This report analyzes the technical, economic, and environmental implications of retrofitting fossil-gas-fired space heating and domestic hot water systems in a prototypical 50,000 square foot office building. We compared a range of system decarbonization scenarios to a conventional gas-fired system replacement including heat pump water heaters, heat pump rooftop units, energy recovery ventilation, peak heating demand management, and on-site solar photovoltaics.