If you step back a bit, it makes sense for society to push for the construction techniques that minimize the lifetime cost of the building. Here, buildings typically last for much longer than 20 years.
And then there's the whole thing where energy costs may not be fully priced into the use.
Sure, but then that is a "political" decision at government level, not your "free" choice.
It is clear that the (good) trend is towards mandating "better" insulation (and thus less energy consumption) but it is not like a government can say "ok, starting tomorrow all new houses must be passive", as that translates to "ok, starting from tomorrow price of all new houses will increase by 30%".
They are introducing - little by little - minimal requirements, and introducing in parallel some (BTW badly implemented at least here in Italy) economic incentives to better existing houses but it will take many years before they can impose "only passive" houses, and in any case, "new houses" are such a trifling percentage of existing buildings that they won't make a dent in the overall energy consumption, it is much more effective, given the amount to slightly better the much larger amount of existing buildings.
Also it is not as easy as it seems, for the last 10-20 years a number of houses have been built in the (at the time) energy classes A-B-C without mechanical ventilation/heat exchangers, with - let's call them "not fully tested" - construction methods and now that they are aging they show the problems emerging (humidity/mould, maintenance of windows, decay of insulation packets/facades, etc.), as often happens with new technologies.
>construction techniques that minimize the lifetime cost of the building. Here, buildings typically last for much longer than 20 years.
And then there's the whole thing where energy costs may not be fully priced into the use.
It goes both ways. Investing in capex has to be balanced against potential capex and opex market changes, not just today's market.
Unless that 0% rate gets passed onto you, there's a fairly rigid payback wall at 30 yrs where no amount of investment is going to make financial sense. (It's why despite loan terms growing for everything else, mortgages are still capped at 30 yrs.
What happens when the market is flooded with cheap renewable electricity, as is promised? Suddenly your payback period is extended beyond what makes sense.
Or advances in technology result in a cheaper, better insulation material?
And then there's the potential external costs of not just energy, but material and construction. It wasn't that long ago that asbestos singles covered nearly every new house because of its fire resistance and insulating properties.
The cost there also seemed to pay for itself, until we discovered the true cost of asbestos mitigation and removal.
And then there's the whole thing where energy costs may not be fully priced into the use.