Decision on large building plot: Basement or bigger house?

Hello,

we have a plot of land with 820 m² on which we want to build a house (for 2 adults and 2 children). Now we are very undecided about the fundamental decision of what/how it should be. The discussion is about:

1. Everything on one level (approx. 160m² similar to a bungalow on one level but with a normal roof that remains empty for a later extension except for insulation) since the plot is large enough.
2. A classic house on 2 levels (ground floor with living room, kitchen, etc. and upper floor with parents' & children's rooms + bathroom)
3. Building a basement
4. or making the house bigger and saving the basement

The cost factor is of course important in the considerations.
Is it cheaper to just make the house, say, 20-40m² bigger and save the basement???
Is it actually more expensive to build everything on one level like a bungalow???

I would like to ask a construction company but I don't trust them because they have a vested financial interest in one solution or the other :-(

So it would be great if some people could post their opinions and especially their experiences about this. Thank you very much!

Do you not have a planner?

1. What counts as the shell, you have to insulate
2. multi-storey means: ceiling, stairs,... depending on the energy standard, more would be added
3.+4. if it is a hillside location, it would be advisable
(otherwise see other basement discussions)

Don't you have a planner?

What/If do you mean by planner? An architect? We don't have one yet. Can he say anything about the costs? I don't want to ask a builder because I hardly expect an objective answer from him...

1. + 2. Is the thermal insulation really that expensive??? Unfortunately, your two answers don't tell me much
3. + 4. The plot is absolutely flat. I don't think a basement makes sense there... Or?

Hello,

yes, for example an architect. Of course he can advise you, he has the appropriate experience and will approach your task independently. But this requires a bit more, for example I only do the cost calculation with the preliminary design, before that only an estimate.

Regarding 1. that reads to me as if you want to partially omit the thermal insulation at first. The point "expensive" is again related to the energy standard of the house. You also cannot ask what lightweight alloy wheels for a car cost.

Regarding 2. here I list a few components that you need additionally for multi-storey construction. To be precise, you do not even formulate a goal yet, so what you want.

Regarding 3.+4. No, here a basement is actually just a pure cost factor, unless you play drums,...

An important factor in the considerations is, of course, the cost factor.
Is it cheaper to simply make the house say 20-40m² larger and save the basement???
Is it actually more expensive to build everything on one level like a bungalow???

Hello LoboNr1,

great possibilities you have there. Such a plot offers opportunities that I would definitely use in your place. Living on one level is so pleasant that it’s okay if it costs a bit more. If you leave out the basement for that, these additional costs are already offset. With such a huge basement area, in my opinion, a basement doesn’t make sense anymore anyway. Nowadays, the building services (even a heat pump with a large buffer tank) hardly require more than 6m². Of course, you have to insulate the entire house (including the attic), but that’s how I understood your description anyway. If you make the house somewhat larger instead of having a basement, this mainly creates more volume; the ratio of room volume to wall outer surface area thus improves. There won’t be that much additional wall surface to be insulated. However, this also makes your attic bigger again, so what’s the objection to using part of the attic as a “basement”? There’s no difference whether you carry dirty laundry up and clean laundry down or carry dirty laundry down (to the basement) and clean laundry back up.
When the attic is eventually converted, probably for the children, a free space for laundry and storage automatically emerges on the ground floor. The only thing I would keep on the ground floor is the building services, unless you install a gas condensing boiler, which goes under the roof anyway. You will have to clarify the details with an architect; you need one anyway.

Regards, Tomtom