miccolis, "My initial reaction would be to stick with gas and get a 96% efficient boiler which would probably be much more efficient than the heat pump."
I can't tell you how many times I've gotten this from contractors.
How is nobody seeing this as an opportunity to be the go-to shop for heat-pump installation. In DC there are thousands of nearly identical row-houses that will all need the same upgrades as we move away from fossil fuels.