Perimeter insulation / floor slab insulation / brick width / window

Well, flying around ... take nordlys as an example. 800€ gas for I think about a 110sqm bungalow? We assume 500-600€ electricity (geothermal) for ~195sqm. Thanks to the insulation, we save massively on the sizing of the heat pump and the depth of the drilling. Thousands of euros. But if you’re using gas anyway, which is also okay, it doesn’t matter again, because those things can release way too much heat anyway. It’s also a question of the overall concept of what makes sense.

Ultimately, it will have to be seen what happens with energy prices in the future. If you can’t afford the investment now, that’s just how it is and your personal priority. Everyone has to decide for themselves. It might be more expensive later but no one knows if that will be the case. Those who use little energy don’t have a big issue with rising consumption prices.

Besides economic efficiency, there can be other factors. A basement with 5cm perimeter insulation probably won’t be heated and won’t be reasonably heatable later and will be more useful for storing potatoes (by the way, quite a lot of money, such a basement, for storing potatoes – think about that). You have to know what you want. A better insulated glass is also more comfortable when sitting in the armchair and having it behind your neck. Savvy savers have fresh air openings installed in the window frames to let cold outside air flow in. Maybe none of this is a drama, but others avoid that and expect more comfort from the new build than what 20-year-old existing properties can offer. It also has to do with resale value.

If the budget is tight now, I would put the investment into the structure and possibly retrofit the equipment later. For example, if a fireplace is planned, I would cancel it immediately to set the house up energetically better. Just as an example.

A basement with 5cm perimeter insulation will probably not be heated and will also not be usefully heatable later on, and thus will be more useful for storing potatoes (by the way, quite a bit of money for a basement like that, for a potato storage - just think about that).

Except for the building services room in the basement, all rooms will have underfloor heating. Would better perimeter insulation be sensible from this perspective after all?

I am honestly curious how the Energy Saving Ordinance is supposed to be met with the rather thin insulation. But as I said, it has to be calculated. Nevertheless, it appears quite thin.

We expect 500-600€ electricity (geothermal) for ~195sqm. Thanks to the insulation, we save massively in the sizing of the heat pump and the depth of the borehole. Thousands of euros.

Since I am also planning a new build with just under 190 sqm and geothermal energy, I would be interested in more precise figures here. That means, what do you roughly save individually over the thumb and compared to which insulation, and which do you have now. Thanks in advance.

Search for that in the forum, there have already been several threads where people posted their consumption. Otherwise, you can also find a heat pump database with such content via Google.

We are building at KFW 55 level, heating load is at 5.5kW compared to ~7.5kW if it were built only according to the energy saving ordinance. That saves about €1000 for the smaller heat pump and ~€2000 for the less deep drilling.