Argh, those are general statements that are not correct at all, and moreover, they do not refer to the property
Says who? Do you have any idea what the etc will cost you for this property?
Generally: space is still more expensive than a slab!
Also keep in mind that with a you don’t have to plan the utility room on the ground floor.
Generally: 10sqm of space versus 80sqm of floor area... the remaining space in the basement is unnecessary, you just have it, but you pay for it.
If you plan smartly, the basement or underground floor will not end up costing you more than your supposedly cheap solution.
Simple calculation:
1. 10sqm of living space for utility room: €25,000
2. 80sqm basement built to basement standards: €120,000
You can also add a foundation slab of €30,000 to position 1... The total result is not surprising.
Whatever! Here you have to think in 3D whether you use the slope to build an underground floor plus one floor and then that’s it.
Not an extra floor, which you call a basement and do not use, but that creates living space as the underground floor, and then another one on top that covers the rest of the living space needed.