Residential Deep Energy Retrofits

Research Report A1401


Rachel Cluett and Jennifer Amann


This report explores energy efficiency programs that target deep energy savings through substantial improvements to existing residential buildings. As states and regions set targets for reducing building-sector energy consumption, it is increasingly critical to scale up deep energy retrofit work. Only one utility-scale deep energy retrofit program exists at present in addition to several research and development projects.

Deep energy retrofits aim to save 50% or more of the energy used on site in a home as compared to actual pre-retrofit usage or an estimate of energy use based on housing and climate characteristics. These savings are realized through improvements to the building shell including insulation and air sealing, and often through upgrades to high-efficiency heating, cooling, and hot water systems suited to the smaller energy load of the house.

This report presents findings in four areas: workforce, retrofit measures, costs, and energy savings. We conclude by identifying barriers to scaling up deep retrofit work and strategies for overcoming them.