Our Victorian style all electric home was built in 1986 using available insulating materials and HVAC technologies that existed at the time of construction. Specifically, the home was insulated using 2x6 walls with fiberglass batt insulation with 1 inch double foil faced PIR (polyisocyanurate) foil taped panels placed on the interior walls, covered with sheet rock (R28). The attic space was insulated with blown in fiberglass (R40) with a polyethylene vapor barrier. We also used triple glazed high R windows, inset and insulated the band joists for both the first and second floor, and confined the forced air duct work, plumbing, and electrical to interior walls and used low profile surface outlet boxes at the base board to keep the perimeter walls intact.
The original A-A heat pump continues to serve us well for both heating and A/C. A number of years ago we added a pellet stove that we use when the outside temperatures drop. The pellet stove can easily heat the entire house even when the outside temperatures are 0 F (we turn the heat pump off).
I'm currently investigating the installation of a geothermal W-A heat pump for the future.