Sacrifice the basement for 20m² more living space?

Thank you very much for the answers

In this area, a two-story construction is common. Honestly, I have not seen anything else so far among the plots available for purchase.

It was planned that my private retreat would be in the basement (shisha room + place to withdraw). I do not want to smoke in the house itself (ground floor + upper floor) or prefer not to.

We have not looked into it in detail yet, but I would say that (if you actually assume 70 sqm) the layout would have been planned approximately like this:

retreat room 20 sqm
storage room 15 sqm
laundry 10 sqm
heating 10 sqm
possibly pellet storage 5 sqm
10 sqm hallway / stairs

Thanks first for the approximate cost breakdown. The reference prices you mentioned are probably only a rough guideline. For me personally, it was more in the direction of:

"If you have 20 sqm more living space and therefore no basement, you can probably save xy €."

With the 20 (maybe even just 10) additional sqm of living space, we will probably manage well. The loss of the retreat room will hurt me a bit more and that is hard to compensate for with money I would then move the storage room into the garage. I saw that there is a pretty cheap "extension" available for prefabricated garages.

In this area, a two-story construction is common. Honestly, I haven’t seen anything else so far among the plots available for purchase.

Since you are still at the beginning of your planning: the so-called city villas are two stories, but not the typical single-family house with the sloped roof on top. True two-story construction (no slopes on the upper floor) is actually only rarely permitted.

I just looked at a local development plan here (and uploaded it)

The floor area ratio says 2 -> so I assume that 2 full floors are possible?
The other development plans are very similar here.

But I don't really want to get hung up on that. Whether it's 1 full floor + roof slope or 2 full floors is not necessarily the question of my post.

I would be happy if someone else would comment on the topic

the plan was to create my private domain in the basement (shisha room + retreat)

Yes, cool... man cave
Our office serves this purpose - well, I often call it a man cave because of the color scheme (dark wood and jade-colored walls).
But shisha is just... no idea... it would be nice if you could explain that to us. It's not like smoking cigarettes, couldn't shisha smoking be integrated on the ground floor (guest room or something), if you give up on the basement?

retreat room 20 sqm

More generous than the children's rooms ... the other rooms are also more than spacious.
However, if you want a pellet heating system, a basement is advisable again...

I don't actually want to dwell on this. Whether it is 1 full story + pitched roof or 2 full stories is not necessarily the question of my post.

... but it is somewhat related: if you need 80 sqm of space upstairs, but are only allowed to build one story, you would have to build 120 sqm downstairs, since upstairs only 2/3 of the lower living area may have a height over 2 meters. Then roughly 40-50 sqm would be left over on the ground floor, for a generous utility room and retreat

Hello,

The floor area ratio is 2 -> so I assume that 2 full floors are also possible?

In the uploaded development plan, the floor area ratio is 0.3 and the site coverage ratio is 0.6; this has nothing to do with the permitted number of floors. This is determined by the allowed ridge and eaves heights, which are also described in the textual provisions.

As it appears, according to this development plan, you could build both a one- and two-story building.

Rhenish regards

Ok then I definitely need a plot that allows two-story building. 200 sqm is simply too much... The bottleneck is unfortunately the upper floor because we need so many rooms (or rather, that's what my wife imagines). The basement area was more like planned "now that it's already there, we have to make use of it".

More spacious than the children's rooms

By the way, also bigger than our bedroom, but there is enough space in the basement anyway

If you want a pellet heating system, then a basement is recommended...

If you don't want gas/oil because you don't want to be too dependent on oligarchs, basically only pellets/heat pump remain. Without a basement, basically only the heat pump. It is not yet decided that it has to be a pellet heating system, but so far that was the most appealing to me. I am also very flexible there.

I personally don’t find smoking in the living area so great because the smell can quickly spread throughout the whole apartment. However, that’s not so important to me that I would have to design the whole house planning around it. I think there should be solutions to appropriately "isolate" the shisha/gentlemen’s room (which is actually only needed in winter) from the living space.