I keep forgetting how hopelessly after on the insulation central Europe is compared to us in the north. A friend of a friend built a house by Swedish standards in the UK a while ago and all her neighbors pitied her because the snow remained on her roof during winter.
We have that, too. But highly insulated houses have new problems: air quality can be bad and houses need an extensive fresh air supply system. Moisture needs to be removed from the air, too. But if coal&oil, now gas and future electricity would be cheap, there would be little incentive to develop working solutions. There are also concepts like 'virtual power plants': a virtual power plant consists of a bunch of renewable electricity producers (solar, wind, ...) and a gas power plant for back up. The gas power plant would then also provide the heat for homes in a centralized fashion. The efficiency of such a gas power plant could then very high. This would work for residential areas. The gas could also in the future be produced from local renewable energy sources.
UK is much much worse than Germany tho. And as an Austrian I have to say that most scandinavic houses I have been to (including iceland) were much worse insulated (both thermally and acoustically) than the houses in Austria.