Thermal system-specific and net-zero carbon least-cost design of new houses in Canadian cold climates

Whole-building model optimizations have been performed for a single-detached house in 5 locations with varying climates, electricity emissions factors, and energy costs. The multi-objective optimizations determine the life-cycle cost vs. operational greenhouse gas emissions Pareto front to discover the 30-year life-cycle least-cost building design heated 1) with natural gas, and 2) electrically using a) central air-source heat pump, b) ductless mini-split heat pump c)ground-source heat pump, and d) electric baseboard, accounting for both initial and operational energy-related costs. A net-zero carbon design with grid-tied photovoltaics is also optimized. Results indicate that heating system type influences the optimal enclosure design, and that neither building total energy use, nor space heating demand correspond to GHG emissions across heating system types. In each location, at least one type of all-electric design has a lower life-cycle cost than the optimized gas-heated model, and such designs can mitigate the majority of operational GHG emissions from new housing in locations with a low carbon intensity electricity supply.