Why are modern houses so warm?

So

3. What are the advantages and disadvantages of not having a basement?

The best thing is to use the forum search for this, it has been discussed extensively here within the last year.

The conclusion was ultimately: It depends very specifically on the needs, the requirements, and the property itself (slope location, property size ...), and on one's own "opinion" on the topic of basements. If you only need it as additional storage space without special requirements, then above-ground storage space is cheaper.

I can't understand the cooling aspect - we consciously decided against it; many bad experiences with damp basements in the neighborhood of our house.

Of the 12 houses in my new development area, 3 have basements and 3 are dry and without moisture problems. If there is dampness, there is a defect somewhere in the new construction.

It is cooler in the basement in summer, however, but it is not a cooling system for the house itself. As storage space or fitness area etc., it can be advantageous.

That the houses are warmer when heated can only be due to wrong settings/wrong heating system; here (in my relatively new house) it is not too warm when heated.

In summer... when building, you have to pay attention to heat protection. But during extreme heat waves, only active cooling helps, but that is no different than before. In my house, at least, it was not warmer this summer than in my parents’ house built in 1982 (which has very thick, well-insulating brick walls for that time).

Of course, you can build with a basement in the swamp, but you don’t have to. With us, it was exactly what you said, an individual consideration.

Many thanks for your quick and clear reply. A wrong setting of the underfloor heating only comes into question 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...

Once the heat is in the house, it takes its time until it is out again. The drafty old building gets hot inside much sooner, but also cools down faster. If you use summer thermal protection, it stays very cool in the new building for a long time – in the old building, you’re already baking. In winter, it is simply a matter of heating settings. You can also have it with underfloor heating at a “cozy” 18 degrees. No problem at all. I personally would not want to do without controlled residential ventilation anymore. It’s not only the regular airing that you save yourself. Odors from the kitchen or the toilet also disappear quickly – tonight we have fish from the pan at our place. Besides running the hood, also run the controlled residential ventilation strongly, and the air throughout the house is really fresh again quite quickly.

It's all about the overall package when it comes to new construction.

In the summer, it was pleasantly cool and stayed cool for a long time in the house. At the moment, the warmest room is the main bathroom at 21 degrees. We don't like it too warm. But we wouldn't want to do without the underfloor heating anymore. You just have to learn how to deal with it first.

Summer or winter: through insulation (no matter how, so energy-saving ordinance compliant) energy cannot escape from the house as quickly. But that is intentional. Who wants to waste energy, whether through gas, electricity, or sun?

1. Many modern houses are constantly uncomfortably warm. What is the reason for this?

Among other things:
a) Heating not properly adjusted / operated. Of course, you can also properly set up underfloor heating so that you get your desired temperature. With the factory settings, which many heating installers commonly "leave behind," this usually does not work. You have to familiarize yourself with it and take care of it yourself.
b) Missing heat protection (roller blinds, pleated blinds, ...) on the windows in summer
c) Controlled residential ventilation with heat recovery operated in such a way that the heat exchanger is on and even more warm air enters the house
d) Open windows and terrace doors at 33 degrees outside temperature
e) Something in jest: The builder skipped the air conditioning. Well - the few hot days we have here per year, we can easily manage those, even with 25 degrees inside the house

2. Is it still possible to build with HK today at all? And can you get by without a ventilation system? We ventilate often, so we don't really understand the reason for such a system...

a) Of course you can build with HK. These have even become very compact nowadays. There are people - including my wife and me - who know underfloor heating and therefore don't like it. We were happy to finally get rid of it when moving into the house. Contrary to the statement by Mycraft (whom I appreciate) above: You don’t have to operate HK today with a supply temperature of 60 degrees. My system is set so that at design temperature (-20 degrees) the supply reaches 50 degrees. In practice, this means that at temperatures around 0 to -5 degrees, the supply does not reach 40 degrees. That is enough to heat the rooms to 22 degrees. A good friend of mine from Bavaria even set only 45 degrees at -20 degrees and manages with it. The floor/floor slab is well insulated and therefore usually only 0.5 to max 1 degree colder than the surrounding temperature. On a 21.5 degree "cold" floor, I can easily walk with socks on!

b) Personally, I no longer want to do without controlled residential ventilation with heat recovery. Ventilating through windows becomes unnecessary. Especially in winter, this saves energy. You always have fresh air in the house. Due to the filters in the system, my wife has significantly fewer allergy problems in spring than before. Thus: For us personally, controlled residential ventilation is very valuable and represents an increase in well-being. Friends of ours next door have a similar house as we do, but without controlled residential ventilation. The air is always stuffy/stale there, even though they ventilate through windows. Depending on the system technology used (Q_p) and house insulation (H_t), you do not have to use controlled residential ventilation.

3. What are the advantages and disadvantages of not having a basement?

Personally, I see only advantages and one disadvantage in a basement. In most cases, you can build with a basement. The disadvantage: Is the price (I couldn’t afford it). A basement is expensive and usually costs 40-60 thousand euros. This is unfortunate, but cannot be changed.

Best regards Thorsten