By switching from burning Russian hydrocarbons for heat to heat pumps so you can heat and cool while being more efficient? This isn't a rebuild, it is a moderate adaptation to the actual requirements to live in the Europe of today.

For steam based heat systems there is also cooling options, so that is a fix for those cities with central heat service.

Cooling buildings with air-water heat pumps like you would use to replace an oil or gas furnace doesn't work very well.