There have been one or the other prices for shell construction to read here recently and I think with ~195sqm of above-ground living space, I’m doing well with 85k including sewer shafts and soil. Built with calcium silicate bricks. For that, I thought my facade costs would be higher because I need the ETICS, so not just plaster and paint, but that’s also not the case in this comparison here.
In my HLB trade, sanitary piping, heating including underfloor heating (ground floor, upper floor, one room in the basement), all sanitary fixtures in normal to upscale quality (aka rain shower, because the OP mentioned it) and centralized controlled residential ventilation (Zehnder, about 13k) were included.
By the way, I also build with KS, therefore ETICS on top, and admittedly, the building volume is not a box but has a few projections and recesses, which does not make it cheaper. Let’s say 5k less, but those were only rough reference points +/- 10%. On average, it is useful as a rough guideline, I think.
Your 85k sounds like a good price. But if you add what one calculates for a basement, namely 80k, then you are not that far off.
We had to build a basement because the plot was quite small. Watertight shell due to clay soil, earthworks with rock inclusions and partial soil replacement (clay is not compactable) unfortunately don’t come for free and cost accordingly – even on a flat lot, because that’s what ours is. But the OP asked about a basement.
ruppsn talks about 13k€ for a staircase, so what must a super fancy one cost or including a very expensive railing? We will have a straight staircase in exposed concrete, which already costs more than planned at 6.5k€. The same in steel stringer and oak steps, so rather simple equipment, would have cost just under half. Prices without railing.
Well, with a basement, there is another staircase – and then you’re also at 13k. By the way, we are installing a flat steel stringer staircase with landing and solid wood oak steps. The covering doesn’t make the difference; it’s simply because we have to bridge 2 floors. Nothing extravagant like a Cliffhanger or similar. You would probably pay what we pay for 2 floors for just one floor with that. Two-stringer stairs are what property developers like to install and are accordingly inexpensive, true. If you like it, why not. But it is not necessarily what fits a normal to upscale standard for me, so I based it on our staircase.
Otherwise, I completely agree with you. Estimates can’t be given much more precisely at this stage of planning. However, I clearly stated with my numbers that they are only very rough and can easily have a 10% variance, if not more. We already discussed how regionally very different the costs for geothermal heating are. I would have loved to take it, but with 12k to 15k surcharge (namely the drilling costs here in Middle Franconia), it was unfortunately not justifiable. In your case, from what I remember, it was significantly less – that shows how extreme the differences sometimes are.
Another randomly picked point
to validate the interior doors trade, because Karsten said “simply in white” (paraphrased) is enough. Well, interior door, white, CPL, hollow core, Hoppe Amsterdam door handle, installed in Lüneburg at my parents’ place (that’s northern Lower Saxony) 450€/piece. In a basement house (see OP’s wish) you accordingly have rooms, i.e. basement, ground floor, upper floor in total maybe 11 doors -> about 5k. And here we are not talking about block frames or similar, where a door easily costs 1000€.
But as I said, the numbers should only show that 420k with the wishes is sporty and offer a rough orientation.