> Main problem is that it wouldn't work with buildings designed for higher heating temperature so it is limited to new builds.
That's no longer the case with modern, multi-stage high temperature heat pumps [1]. These consume more electricity, yes, but still achieve far better efficiency than straight burning fuel or resistive heaters.
That's no longer the case with modern, multi-stage high temperature heat pumps [1]. These consume more electricity, yes, but still achieve far better efficiency than straight burning fuel or resistive heaters.
[1] https://www.buderus.de/de/waermepumpe/hochtemperatur