You do have to factor in the cost of utilities and where I live electricity is very expensive. Even here regular heat pumps are cheaper than heating with propane or oil (or of course resistive electric) but gas is still cheapest. Installers generally recommend a hybrid system so you can use the heat pumps in the shoulder seasons, but gas when it’s cold. If you could use a ground source heat pump or solar panels, that changes everything.

But all that is hugely expensive to convert to and we’re not going to make any progress if that’s the way forward. Requiring it for new construction, where it’s much cheaper, is the least we can do, but this is something that’s worth a little government help

My state still has incentives for landlords and homeowners by income level: any chance there’s some help there?