What is cheaper? OG or KG?

I would basically be interested in what you think is cheaper.

The following plan:

A house is to be built. The ground floor should be about 65 sqm. Bathroom (9 sqm), kitchen/living room (35 sqm), bedroom (15 sqm), hallway (7 sqm).
More rooms are needed: technical room (10 sqm), office (18 sqm), guest room (12 sqm), storage room (8 sqm).
About 48 sqm more would be needed for this.

Now the consideration is: Either add an upper floor on top of the ground floor or build a basement.
The upper floor can have some sloping ceilings, since the entire 65 sqm is not needed.

The whole thing should be a KfW 40 house with a heat pump.
The basement would then also have to be fully developed and insulated as a living basement.

The advantage of the basement I see:
The technical room can go into the basement, all connections come directly there.
Less facade to maintain and keep in good condition.

The advantage of the upper floor I see:
Little earthwork necessary.
The upper floor can probably be built more ecologically than the basement (resources).
More light in the office + guest room.

What might also be relevant: It is to be a timber frame construction with a wooden facade.
The following own work:
Most of the electrical work is to be done by myself, non-load-bearing partition walls can be installed by myself, bathroom expansion partly by myself. Floor coverings and painting myself.

So, now I would be interested in how it works out cost-wise. What is cheaper? Upper floor or basement?

I don’t need any inquiries yet, as everything is still at a very early stage and the earliest build date will probably be in 3 years. I would just be interested in your assessment so that I have a rough idea in which direction my considerations can further develop.

Thanks in advance.

Best regards
Specki

What is cheaper? OG or KG?

Since you need a roof anyway, you can build the OG cheaper than the basement fully developed as living space. Exception: Due to your soil conditions, you have to dig a lot anyway. Then the basement might be built cheaply.

A house is to be built. The EG should be about 65 sqm. Bathroom (9 sqm), kitchen/living (35 sqm), bedroom (15 sqm), hallway (7 sqm) Additional rooms are needed: technical room (10 sqm), study (18 sqm), guest room (12 sqm), storage room (8 sqm). About 48 sqm more would be needed for this.

Then you don’t even need a full OG. Maybe an "attic conversion" will suffice. Then both advantages of the basement that you see disappear. No more facade than with the basement house. And for the technical installations, it doesn’t matter at all whether they are routed through a basement wall or simply under the slab and then arrive directly in the utility room.

An OG is significantly cheaper.

Yes exactly, that's how I imagined it. Basically a one-and-a-half-story house, which then has partially sloping ceilings in the upper floor that wouldn't be bothersome.

Thank you for your comments, that confirms my assumption.

Regards
Specki

I would reconsider the room layout; who would want the technical room and storage room upstairs and always carry their crates of drinks, tools, etc. upstairs? The washing machine would also be upstairs, while the bedroom and bathroom are on the ground floor, right? You also need space for a staircase in addition to the 7sqm in the hallway.

Best regards
Sabine

Curly, you’re already thinking way too far ahead

We are currently in a kind of basic planning phase. How the exact room layout will look will only become clear in the next 2 years.
Possibly, the entire building will be completely different anyway. Two residential units, one upstairs and one downstairs. Of course, then larger.

So a lot is still up in the air. For me, it was first about what is cheaper. Basement or upper floor.

Regards
Specki