Is the basement cost estimate realistic?

I think you're pretty close with the ±80, depending on the equipment a bit more. Just had a conversation with GU, basement total 64sqm, no bathroom, WC or anything, of which 24sqm with underfloor heating/parquet.... 70-80k.

GD

With 2.2m you are already below the minimum size in some state building codes or exactly at the lowest limit for living rooms.

Where? I know the minimum size is 2.30.
2.20 is and remains a basement – despite light well and carpet and wallpaper.

Depending on which sport you want to practice, 2.2m can also already be too little.

That rules out quite a bit. But many builders think they will do the same thing for 30 years. Dumbbell in hand and a few biceps exercises or cardiovascular activity by jumping and jumping jacks will already get quite tight ;)

So I read it as 2.2 m clear room height without floor construction, i.e. it will be about 2.1 m later and thus purely a utility basement. Residential basement presumably starts at 2.3 m (building regulations). The price itself seems quite cheap to me, but your construction supervisor should be able to tell you what is currently estimated for the expansion in your region.

Best regards

Hello! First of all, thank you so much for your many comments. There were really a lot of points that made me think a bit more. Last night I studied the Bavarian Building Code. According to it, the office / computer room would be classified as a living space, which means that according to BayBo a minimum room height of 2.4m, natural light amounting to 1/8 of the net floor area, as well as a second escape route are required. This, of course, brings completely different challenges. I would be interested to know how others have dealt with the second escape route? Is there a separate basement staircase here? Besides that, I was particularly struck by the interpretation that rooms which are "suitable in terms of their condition" for such use are also considered living spaces. To me this means that even a room with underfloor heating can be converted into a living space with little effort.

However, if I state in the building application that it is a storage room / basement room, but then use it differently, I would be violating the building application and it would be an "illegal construction." Sure, where there is no plaintiff there is no defendant... but still.

A lot falls away here. But many builders think they will do the same thing for 30 years. Dumbbell in hand and some bicep exercises or cardiovascular activity through jumping and jumping jacks will get quite cramped ;)

I have a cross trainer, a treadmill, a power rack, a cable tower, and free weights. That should be enough for the next 30 years - even with a lower room height ;)

Depending on body height, 2.2m on the treadmill can already be tight.

A buddy got his basement about a year ago. Also about 65-70m2 pure usable basement without light wells, no underfloor heating. 2.2m upper edge of the floor. Energy saving ordinance standard and about 80cm above ground. It cost about 70000 without earthworks.