Basement height 1m vs. 60cm - Cost perspective

Hey,

we are with our architects at a very advanced design stage shortly before applying for the building permit.

One of the last decision points: Should the basement (with [weißer Wanne]) protrude 60 cm or 100 cm from the ground.

According to our architects, we save a bit of money at 100 cm, but it would hardly be worth mentioning. At the same time, however, they see [Erdarbeiten] and the [weiße Wanne] as significant cost elements.

My understanding is that [Erdarbeiten] and [weiße Wanne] would have to become noticeably cheaper if we go 100 cm out of the ground (less excavation, less [weiße Wanne] concrete, less volume that has to be elaborately protected against moisture). Visually and with regard to the terrace etc., 100 cm would be fine for us.

Is it worth going for 100 cm basement height, how do you see it?

According to our architects, we save a little money at 100 cm, but it would hardly be worth mentioning.

I see it the same way.

As I understand it, earthworks and the white tank should become noticeably cheaper if we go 100 cm out of the ground (less excavation, less white tank concrete, less volume that needs elaborate protection against moisture).

These are not massive cubic meters of earthworks being saved now. And the basement is completely made as a white tank – it doesn't matter to it whether it is completely in the ground or sticks out a meter. Everything is concreted. And elaborate moisture protection is not such a big deal either; that's exactly what you are building with the white tank.

Is it worth going for 100 cm basement height, what do you think?

What is the property situation and the construction plan? You save something on the basement, which you might spend again through another terrain modeling. The front door is then also one meter high – building a ground-level access or stairs (both cost additional money as well). Does the total house height still fit the specifications of the development plan? How does the appearance look at all? I personally find a terrace that high totally inconvenient to just step into the garden. If there is no serious reason to have the basement stick out, just dig it in normally and enjoy a probably nicer and more practical house. Save yourself the significant extra costs for entrance and terrace. Maybe your savings are even a naive calculation? All just speculations, since you don't even present your building project to us, and in my opinion your question can be answered separately – but the answers can go in all directions and be right or wrong.

Thank you, Jens, for your assessment, that already helps me a lot.

What is the situation with the plot of land and the construction planning?

since you don’t even present your house building project to us

Sure, I can gladly do that:
Single-family house, two adults, currently one child, prospectively rather two children
Plot about 750 sqm, located about 0.5m below street level, in BW, LK Karlsruhe
House: basement, ground floor, upper floor (75% of the ground floor), total 190 sqm

Does that help?

In terms of cost, it is relatively tight for us, because for several reasons (both home office, children, low knee wall on the upper floor and limited upper floor → need a large ground floor to have enough space upstairs) we want/need to build relatively large. Therefore, if it even works out, we will initially only build the house itself, but not garage, balcony, garden, etc., and if possible and reasonable, we will only partially finish the basement or certain rooms.

Hence the question whether it would help to let the basement protrude 1m above ground (the development plan would allow it). It is purely a financial question.

I hope you are referring to an architect – and not just a building permit draftsman, as many clients simply call them. Against the background of the presentation (at least that is how I read it), inflating the total size of the house only so that the attic does not count as a full floor, I still question whether the room program was cleverly devised enough. It would also be helpful to show the planning, which, according to reports, is almost ready for submission.

But first, my congratulations on basically being ready for a raised ground floor (nowadays many clients consider it an indecent request not to have step-free access to the garden). I am pleased to read that the development plan is playing along here as well. Otherwise, I can keep it short and refer to my "like" of the words of my predecessor.

Yes, we planned with a proper architect. The development plan states that the upper floor may only be 0.75, which is why we basically have the situation that the upper floor tends to be too small and the ground floor too large.

Is it common to post the plans here? Personally, I don't mind, but I don't know offhand whether this is allowed according to the contract with the architects. Do you have any experience from the forum?

Can’t you then make fully functional living spaces out of the basement? Then you wouldn’t need a finished upper floor at all, and the ground floor might not have to be that big either.