Lawrence Berkeley National Laboratory

The upgrading of existing homes through electrification will play a critical role in the decarbonization of the residential building stock in the US. Currently, upgrade project cost is the key barrier that the buildings industry and homeowners are facing. These costs must be reduced in order for home decarbonization to scale. The buildings industry currently lacks relevant home upgrade cost data needed to aid in the planning and implementation of home decarbonization, as well as to engage in targeted R&D to lower upgrade costs. To address this, we gathered information on the total project and upgrade measure costs, along with the energy, utility bill and carbon savings from 1,739 energy upgrade projects across the US. We present analyses that summarize the measure and project costs together with estimates of cost variability and trends with key parameters. Our results will focus on electrification technologies and related decarbonization measures. We developed regression models to predict energy and carbon savings based on upgrade measure costs. The regression models were used to determine important factors impacting measure costs, as well as to estimate the costs required to meet savings targets for energy and CO 2 . Our results show that there are currently no low-cost solutions capable of providing significant (>50%) energy and CO 2 savings for the US residential building stock. Carbon reductions of 50% or greater typically required investments of at least $250/m 2 ($23/ft 2 ) or $40-$50,000 per home.