ᐅ Buying a New Single-Family Home: Is the Energy Efficiency Standard Currently Required by Building Codes Likely to Be Adequate in the Future?

Hello everyone,

I have recently become a member of this forum and have mainly been reading quietly and gathering information so far. My research on the above-mentioned topic has not yielded satisfactory results, which is why I am now starting my first thread.

We are a family of four and are in the process of purchasing a detached house with about 165m2 (1,775 sq ft) of living space and a large plot of land in the Hamburg area or its surroundings. This is a new build project being carried out by Bonava.

To keep it brief: Bonava only builds according to the Energy Saving Ordinance standard. The energy is supplied via district heating. There is no possibility to improve the efficiency. A few weeks ago, I inquired whether the standard double-glazed windows could be replaced with triple-glazed ones, and this was later confirmed as possible. So, an upgrade would have been available for a small additional cost.

However, two days ago, I received a call stating this would no longer be possible because some neighbors had previously asked the same question and were denied (for reasons unknown). They now want to apply the same rules to all buyers, even though I was promised otherwise.

I am upset about this and am now considering abandoning the whole project because I feel like I am buying a house with outdated technology. Although it is only the windows, in my understanding, they already make a significant difference.

According to the preliminary energy certificate, the energy demand is 82.3 kWh/(m2 x a) which falls in category C, and the primary energy demand is 51.0 kWh/(m2 x a), which is category A.

Since I am a complete novice, I would really like to hear the opinions of experienced people. I am truly only interested in finding out whether I am getting a solid house or an energy guzzler. Please forgive me if I am posting in the wrong section.

I hope to receive well-informed, helpful, and meaningful feedback.

Best regards
Atilla

Atilla08 schrieb:

listen to experienced people. For me, it’s really just about finding out whether I get a solid house or an energy guzzler.

Hello, this forum is mainly visited by homeowners and those who used to be and are now (happily or less so) living in their own homes.
Of course, everyone has different requirements: some are satisfied with the energy saving regulations, while others aim for something closer to a passive house.
Ultimately, it depends on the budget.
Basically, it should be said: A house, a new build according to the energy saving regulation, will not be an energy guzzler!

Atilla08 schrieb:

According to the preliminary energy certificate, the energy demand is 82.3 kWh/(m2 x a) so within category C and the primary energy demand is 51.0 kWh/(m2 x a) in category A.

Numbers tell me less and, in my opinion, are just numbers, but I’m bumping this post up for those who understand the figures better.

Atilla08 schrieb:

Looking to purchase a single-family house around Hamburg or its surroundings, with approximately 165m2 (1776 square feet) of living space and a large plot. It’s a new build being carried out by Bonava.

I checked: is it Geesthacht? That would be Schleswig-Holstein...

Atilla08 schrieb:

whether the standard double glazing can be replaced by triple glazing

It’s a bit strange that an independent single-family house wouldn’t have other windows installed. But it is what it is.

Still, a house with double glazing doesn’t have to be outdated or worse. We ourselves (and there are quite a few homeowners here who built with double glazing) have “only” double glazing and have an almost KfW55 energy standard. That’s enough for us personally.
Triple glazing doesn’t only have advantages but depends on the overall house concept, for example the insulation of the walls and the ventilation system, otherwise there’s a risk of mold.
So if windows are changed, the exterior walls also need to be considered.
Another disadvantage is that solar heat is filtered into the house: while double glazing lets some heat in (especially now with sunshine, for example), triple glazing and the gas fill inside it filter out heat. During the day, heating might need to run, whereas others benefit from solar heat warming up the floor tiles.

Atilla08 schrieb:

I am frustrated about this and am now considering abandoning the entire project because I feel like I am buying a house with outdated technology. Although it’s just the windows, they do make quite a difference in my understanding.

A house built according to the energy-saving regulation is not "outdated." It corresponds to the theoretical KfW rating KfW 56-75. You are not making a mistake with that.

Apart from that, energy consumption mainly depends on the user, not the house. If your house is well planned and executed, heating costs can be even lower than those of a KfW 40 house.

nordanney schrieb:

Besides that, energy consumption primarily depends on the user, not the house.

I do think the concern is quite justified.
In this forum, everyone strongly recommends triple glazing... just yesterday during the tile discussion, the topic of underfloor heating came up again: while I always say that our tiles get pleasantly warm (without having the underfloor heating on during the day), others don't believe me. Of course: because the warmth is filtered out through their triple glazing and the solar heat isn’t sufficient?! To me, that seems like a logical explanation.

Dear all,
thank you very much for the quick and detailed feedback. That is already very reassuring for us!

Of course, everything ultimately depends on personal preferences and budget. I was just unsure whether we would be happy with this standard, especially since we clearly lack experience here.

I checked: is it Geesthacht? That would be Schleswig-Holstein...

Exactly!

...it's strange that they don't install different windows in an independent single-family house. But it is what it is.

I see it the same way.

For us personally, it’s not about owning a high-tech house, but rather a solid and spacious home 🙂

I look forward to further assessments and opinions.

Atilla08 schrieb:

Personally, we’re not aiming to have a high-tech house, but a solid and spacious home of our own 🙂

Bonava will definitely provide that. They build properly—maybe not with individual creativity, but solidly.