  Building heat electrification is central to economy-wide decarbonization
efforts and directly affects energy infrastructure planning through increasing
electricity demand and reducing the building sector's use of gas infrastructure
that also serves the power sector. Here, we develop a modeling framework to
quantify end-use demand for electricity and gas in the buildings sector under
various electrification pathways and evaluate their impact on co-optimized bulk
power-gas infrastructure investments and operations under deep decarbonization
scenarios. Applying the framework to study the U.S. New England region in 2050
across 20 weather scenarios, we find high electrification of the residential
sector can increase sectoral peak and total electricity demands by up to
56-158% and 41-59% respectively relative to business-as-usual projections.
Employing demand-side measures like building envelope improvements under high
electrification, however, can reduce the magnitude and weather sensitivity of
peak load as well as induce overall efficiency gains, reducing the combined
residential sector energy demand for power and gas by 28-30% relative to the
present day. Notably, a combination of high electrification and envelope
improvements yields the lowest bulk power-gas system cost outcomes. We also
find that inter-annual weather-driven variations in demand result in up to 33%
variation in optimal power sector investments, which highlights the importance
of capturing weather sensitivity of demand for planning purposes.
