ᐅ Which is more cost-effective: upper floor or basement?

Created on: 29 Oct 2019 13:46
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Specki
I’m basically curious about your opinion on what would be more cost-effective.

Here’s the plan:

A house is to be built.
The ground floor (GF) should be about 65 sqm (700 sq ft). Bathroom (9 sqm (100 sq ft)), kitchen/living room (35 sqm (377 sq ft)), bedroom (15 sqm (161 sq ft)), hallway (7 sqm (75 sq ft)).
Additional rooms are needed: utility/technical room (10 sqm (108 sq ft)), home office (18 sqm (194 sq ft)), guest room (12 sqm (129 sq ft)), storage room (8 sqm (86 sq ft)).
This would require roughly another 48 sqm (517 sq ft).

Now the question is whether to add an upper floor (UF) on top of the ground floor or to build a basement.
The upper floor can have some sloping ceilings, since the full 65 sqm (700 sq ft) are not needed.

The house is planned as a KfW 40 energy standard home with a heat pump.
If a basement is built, it would have to be fully developed as a living space and insulated.

Advantages I see with a basement:
The technical room can be located there, with all connections coming in directly.
Less facade to maintain and care for.

Advantages I see with an upper floor:
Less excavation work required.
The upper floor can probably be built more ecologically than a basement (materials/resources).
More natural light in the home office and guest room.

What might also be relevant: The construction will be timber frame with a wooden facade.
The following work will be done mostly as owner contributions: electrical installations, partition walls if non-load-bearing, partial bathroom finishing, flooring, and painting.

So now I’d be interested in the cost comparison. What is cheaper—upper floor or basement?

I don’t need inquiries yet, as this is still in a very early phase and building is planned at the earliest in three years. I’m just curious about your assessment so I can have a rough direction for developing my considerations.

Thanks in advance.

Best regards,
Specki
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borderpuschl
30 Oct 2019 08:04
I agree with nordanny. Depending on how the plot is shaped (slight slope) or the soil conditions (keyword load-bearing capacity, etc.), it can sometimes be more cost-effective to build a basement. Under normal circumstances, however, an attic is cheaper than a basement.

Do you already have a plot? If so, you know the conditions (except maybe the soil quality, which can be determined through a geotechnical survey).
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Fummelbrett!
30 Oct 2019 09:05
I would use the coming years to take a closer look at when, how, and how often you use each room. Also, consider their ideal sizes. Where is space currently tight, and where is free space being wasted? How many beverage crates do you need to store, how many boxes with miscellaneous items (and how often do you retrieve them), how many meters of wardrobe space do you require, how large should the hallway or cloakroom be, bathtub yes or no, kitchen size, living room use, dining area size, overnight guests... and so on. You might want to keep a small notebook—even if it sounds strange at first—where you jot down spontaneous ideas and notes.
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Specki
30 Oct 2019 12:54
Hey everyone,

I know you mean well, but most of the suggestions here don’t really address the topic.

I already own a property. I bought it 4 years ago. It was completely renovated from the ground up and has been my home for over 3 years.

The garden is very large and there might be room for another house at the back.
The plan is that maybe in about 4 years we’ll build a house there to rent out (tax saving considerations).
And once the kids have moved out, we’d move into the house we built ourselves. This is just a rough plan I have in mind and might change, for example, into a property with two separate units, since that would be more financially self-sustaining. The downside: you don’t live alone in the house. The upside: we build a single-story, accessible home for ourselves and recoup the money faster.

For now, I’m mainly focused on the question: Is it better to build an upper floor or a basement?

@ borderpuschel:
The plot is completely flat and currently used as a garden.
A soil survey can be done once the actual planning starts. But that will probably be at least 1 to 2 years from now, since first we’re installing a photovoltaic system on the existing property and then probably the exterior insulation.

I’m sure I’ll have more questions here later.

Cheers
Specki