Single-family house, Energy Saving Ordinance 2016, developer recommends additional insulation - is it sensible?

My goodness, you are really bad at this... I just wanted to tell the OP that he doesn't need to worry if he decides against the additional costs - the house will still be very energy-efficient.

Sorry, the annoyed tone from the OP irritated me similarly.
And apparently I'm a bit slow ... but now I got it! Thanks for your patience.

And I am of the opinion that if you build according to the [Energieeinsparverordnung 2016] "only," it is still energy-saving AND economical. It is certainly more economical ... but unfortunately, I couldn't find out how!

I just wanted to tell the OP that he doesn't need to worry if he decides against the additional costs - the house will still be very energy-efficient.

... that's nice - I had understood you that way too. The problem is just that the additional costs are unavoidable if I want to have a gas condensing boiler. In my amortization calculation, I have to consider these additional costs separately, since the extra insulation might pay for itself.

The advantages of monolithic construction are obvious. You could have also mentioned the issue of attaching external fixtures (canopies, lights, awnings, etc.). As I said, we also considered that, but it’s not just 10cm less in the kids’ room. It’s almost 10m² in total (comparing monolithic 42.5 cm Poroton instead of 17.5cm + 16cm EPS).

Still, I would have appreciated getting a bit more information on how many kWh I can save with the described extra insulation (rough estimate, of course).

Hi Ölschlamm,

What is going on in this thread? There is no reason to be fighting...

Oh, thanks for the answers

: Your hint ultimately leads further (if the numbers are roughly correct). With an air-to-water heat pump, according to my rough calculations, I would come to about 3000 kWh p/a (seasonal performance factor 2.1 is realistic with panel radiators supply temperature 45° - please no discussion, that's how I want it! - and extremely drafty high-altitude location on the Swabian Alb approx. 600 m above sea level - that's probably the max) so electricity for about 750 euros. With the gas system, I would probably come to 6000 kWh minus solar thermal 1500 kWh = 4500 kWh so about 260 euros. Savings roughly 500 p/a with additional costs of 9000,- (gas tank, connection, chimney sweep, etc.). Add another 100 saving from insulation on that, so 600,- p/a. Probably still not a good idea.

michael

If I read your data again, you have already given the answer yourself as to which heating you should choose. Under the boundary conditions (cold area and a heating system that requires 45°C supply temperature) you can simply forget an air-to-water heat pump. It will deliver a seasonal performance factor that is terrible (I consider your 2.1 realistic because for large parts of winter it will run purely electric heating = heating element in the boiler). And the good piece probably will not have a long life. Almost every electrical appliance (fridge, drill, and also drives) is designed for a certain switching frequency and switching duration per hour. A normal drill, for example, max 5 minutes per hour. Your air-to-water heat pump will run at full load much more than intended under your conditions. Don’t expect it to last 15 years.

There are also air-to-water heat pumps adapted to other ambient conditions and higher supply temperatures (different refrigerants, pressures, etc), but I would presume high prices there.

If a heat pump, you will probably have to reasonably choose a ground probe heat pump. And that will again be significantly more expensive than gas with solar thermal, gas tank, etc.

Furthermore, I consider your 6000 kWh heating demand cautiously said, very optimistically estimated. In a warm residential area in Franconia at 360 m altitude on 135 sqm with wall U-value 0.19 plus triple glazing windows, we come to about 10000 kWh heating demand (8500 gas plus 1000-1500 from solar thermal).

So better assume at least 1000 euros/year as electricity costs for an air-to-water heat pump compared to 500 € gas costs.

In my eyes, your question is therefore not "Is it worth insulating more" but "What do I have to do to get the house approved with a gas heating system."

Only two questions I have:

Have you already signed a contract with your builder or are you still negotiating? That means, will the new Energy Saving Ordinance starting 1.1.2016 apply to you? Then you have a problem with your specifications...

What do you have against insulation under the floor slab? This is actually nothing new or unusual and, according to several experts, perfectly okay.

Best regards,

Andreas

Hello,

...true, but payment is made for the m² of living space and not for the built m² - and what do 10 m² of living space cost us?

I don't know how you come to minus 10 sqm, for me 6 cm difference results in 2.40 sqm per floor (in your example); so almost 5.00 sqm in the entire house. Anyway, you have made your decision.

Whether an "increase" in insulation will be effective will be determined by the calculations for the house; financially in terms of heating cost savings it will not. But it "may" be that the increased insulation is necessary to comply with the Energy Saving Ordinance 2016 if you insist on gas as the heat generator.

Rhine regards from the road Building expert

Isn't there any alternative to the air-to-water heat pump besides gas?