Why are modern houses so warm?

Good day,

we are going to build but have some questions about building services engineering, which we have not yet been able to find well-founded answers to.

1. Many modern houses are constantly uncomfortably warm. What is the reason for this?
Our comfort temperature is around 20-22°, but at some acquaintances of my wife (who have built with underfloor heating in recent years) as well as during a visit to the Viebrockhaus model home park, the temperature feels like 24/25°. What is the reason for this? The answers so far have been: it is normal with underfloor heating; underfloor heating is very difficult to adjust; that belongs to the past when only one heating circuit for the entire house was installed; it is due to the insulation of modern houses... I cannot put all the blame on the underfloor heating, because it also gets hot in summer (when the heating is probably off), definitely more than in our rental house (built 1997, gas heating with radiators). What do you think about this?

Personally, I rather suspect the absence of a basement and the large glass area together with the lack of roof overhangs.

2. Is it still possible to build with radiators nowadays? Radiators seem to have disappeared from catalogs and websites. I understand that heating with radiators will nowadays hardly meet the energy saving ordinance threshold... And can one avoid a ventilation system? We ventilate often, so we don't quite see the reason for such a system...

3. What are the advantages and disadvantages of lacking a basement?
Ok, less (storage) space, more noise (because heating etc. is closer to the living area), probably less cooling in summer and it is certainly also a cost issue. But does it have any other effects that one should consider?

Thank you very much for reading and for your answers.

I am available for any further questions.

It is due to a incorrectly set heater, nothing else.

Hot houses
In summer or in winter? In winter, because the resident does not have control over their heating.
In summer, because Viebrockhaus uses many light materials and in the model house park the door is constantly open – shading is also not effective if the house is to be appealing from the inside.
Radiators
Sure, you can build with radiators… but rather not with heat pumps, as these do not provide the supply temperatures – with gas this is no problem; even cheaper.
Ventilation
You can build without it, but personally I would advise you to have a ventilation system. In my parents’ house (built 1987) this is no problem without – in our apartment (built 1997) it smells musty when you come home after 8 hours of absence.
Advantage: cost savings, less stair climbing in old age
Basement
Disadvantage: less usable space, which you might still be able to finish or finish right away. If you have a hobby that requires a lot of space – e.g., a Lego city – it is of course ideally suited for that.
I cannot understand cooling – we have consciously decided against it; many bad experiences with damp basements in the neighborhood of our house.

The reason for the overheating of modern houses lies in the low temperatures of the underfloor heating... sounds paradoxical but it is true...

To heat a house or the air inside it to a certain temperature, energy is needed. This can be provided quickly via radiators with the necessary high flow temperatures or through lower temperatures via underfloor heating.

But to heat the whole house economically with 30 degrees instead of 60, you need mass that you heat up and that can then release the thermal energy to the air. That is the screed... this is where the underfloor heating is installed, and it takes a while to heat the approximately 15 tons of concrete with 30 degrees. Ergo, it takes just as long for the screed to cool down again.

Result: ----> the whole system is very sluggish

Fast temperature changes like with radiators are not possible... every incoming sunbeam heats the rooms, and so it happens that the houses are "too warm," and the prescribed airtightness and the applied insulation do their job and keep the heat inside the house.

2. yes, you can... the customer is still king... personally, I wouldn’t do it... radiators belong to the past... if you want to save money, you install underfloor heating

If you can stick to the ventilation intervals, then of course you can also build without [Kontrollierte-Wohnraumlüftung]... but even here I would advise against building without it nowadays...

3. Advantages without a basement: you save a lot of money... both during construction and later in upkeep and interest. Also, it depends on what kind of plot you have, and waterproof basements are even more expensive than "normal" ones; nowadays, it often simply comes down to money... if everyone had enough, they would all build with basements... many also bring up the argument of age, that later everything on one level is better (which I cannot understand)

Disadvantage: less space, utility room/HAR must be on the living level, etc.

It is due to a wrongly set heating system, nothing else.

Thank you very much for your quick and clear answer. A wrong setting of the underfloor heating is only an option for me if the heating is actually on. But even in summer, when the heating is off, modern houses are often very warm (warmer than, for example, our 20-year-old rental house). Something else must also come into play...

Thank you for your reply.

Hot houses In summer or in winter?

Both: summer and winter

Basement ... I cannot understand cooling - we consciously decided against it; many bad experiences with damp basements in the neighborhood of our house.

The basement is generally significantly cooler than the other floors, so it has a certain cooling effect. Yes, I have also heard about damp basements. It’s not entirely surprising, after all the basement wall is constantly in contact with the earth, which has to give off quite a bit of moisture.