ᐅ Is Basement Space More Expensive Than Living Area?

Hello,

we are planning to build a single-family house in Bavaria, and due to groundwater pressure in the soil, the fully waterproofed concrete basement will be quite expensive. The general contractor said, "the basement costs more than the above-ground living space." Is it really possible that increasing the size of the above-ground house by nearly the same usable area that is lost by omitting the basement results in cost savings? In other words, is a 150 m² (1,615 sq ft) house with an expensive waterproof concrete basement more costly than a house without a basement but with 150 m² (1,615 sq ft) of living space plus 50-70 m² (540-750 sq ft) of utility rooms (the latter with cheaper flooring, etc.)? The general contractor only had a few rough rules of thumb, which obviously didn’t apply well in this case, and did not provide any actual cost calculations. Strangely, he also refused to calculate both options side by side, saying it would be too time-consuming.

Does anyone here have real experience with this? It would be very helpful, thanks in advance!

Best regards

No, that’s not correct. You do need to add the excavation costs on top of the base price for the basement, and this can be very expensive, especially if (which is almost always the case with those volumes) the soil has to be removed or, in the case of poor quality, partially replaced.

Just calculate around 90,000 for a basement of about 80m² (860 ft²); the cost per square meter of living space is significantly higher.

Of course, this only applies if we are not talking about a basement designed as living space.

No, it was meant as a utility basement, with affordable flooring, a lower ceiling height than on the ground floor, and unfinished walls. Above ground, I would still equip the "basement replacement rooms" quite simply, but all with underfloor heating, inexpensive tiles, and painted walls.

I already suspected that was a somewhat confusing statement from the builder. Concrete examples from people who have had both options priced out or who have a good overview of the costs would be very interesting!

Calculating both would mean comparing the same additional floor areas, in other words, a basement versus a full second above-ground floor.

The general contractor’s statement makes sense if "1 or 2 extra rooms above ground" are compared to a partial basement. A partial basement can indeed be similarly expensive per square meter.

We obtained several quotes for our basement because we were initially shocked by the prices. All of them were very close once all costs were included. All-inclusive, including civil engineering, disposal, tiling, stairs, electrical work, etc., we are looking at about 120,000 for approximately 105m² (1,130 sq ft) of basement.

Thank you for the helpful answers! So the 120,000€ was for a full basement with maximum waterproofing and cellar window sealing? Based on my area, the 90,000€ estimate would mean that at 1,800€ per m² (approximately 167 per sq ft) of above-ground living space (rough estimate from my general contractor for a house without a basement), you could increase the house footprint by about 50 m² (540 sq ft) for roughly the same cost. Does this kind of calculation make sense? Or do I need to approach it differently to get a rough estimate? My general contractor’s rough values might need to be taken with caution.

I just saw in your profile that you are from Saxony – so prices there are already close to the level in Bavaria...

The mentioned price also applies to a basic basement constructed as a waterproof concrete shell ("white tank"), including 5 windows with light wells and finished tiled floors (no painting included, for those who prefer it that way).

Your rough estimate is fairly accurate. We considered reducing the house size, and for a 25cm (10 inches) recession, we were credited 3,500€—which corresponds to about 7.5m² (81 square feet) cumulatively across the basement, ground floor, and upper floor.