We are currently working with an architect on the preliminary design for a single-family home. The architect recommends a partial basement for cost reasons. The planned partial basement would have a floor area of approximately 57m2 (613 sq ft) and would include a utility room, laundry room, and an additional storage room that could possibly be used as an office or hobby room. In terms of size, this would be sufficient for us. A full basement would have an area of about 118m2 (1,270 sq ft). We do not want to completely forgo having a basement.
Here in the forum, I have often read that a partial basement saves little cost because expenses for foundations, etc., must be offset. According to the architect, however, these costs are minor compared to the additional expenses for excavation and removal of soil, walls/masonry, doors, electrical work, windows, light wells, finishing, and so on.
The architect estimates the cost of the partial basement at around 50,000 EUR. For a full basement, his calculation adds about 40,000 EUR more, totaling approximately 90,000 EUR, which seems quite high to me. However, this would still represent a potential cost saving in my view.
What is your opinion? Does anyone have experience with the costs of partial versus full basements?
Here in the forum, I have often read that a partial basement saves little cost because expenses for foundations, etc., must be offset. According to the architect, however, these costs are minor compared to the additional expenses for excavation and removal of soil, walls/masonry, doors, electrical work, windows, light wells, finishing, and so on.
The architect estimates the cost of the partial basement at around 50,000 EUR. For a full basement, his calculation adds about 40,000 EUR more, totaling approximately 90,000 EUR, which seems quite high to me. However, this would still represent a potential cost saving in my view.
What is your opinion? Does anyone have experience with the costs of partial versus full basements?
G
Gartenfreund14 Apr 2015 06:39I can’t really comment on the costs. Certainly, you will have about twice the amount of excavation, a bit more concrete, and so on, which of course will cause additional expenses. With a full basement, however, you also have the option to include a storage room there and set up both an office and a workshop.
I just looked into light wells. These seem to be available starting at around €70 (about $75), and according to online sources, the price of a basement window is around €100 (about $110), all without installation. So, it doesn’t cost that much more.
Please correct me if these prices are wrong.
Regarding the other items you mentioned, such as doors, interior finishing, etc., it is definitely possible to start on a tight budget. A light switch and a ceiling light don’t cost much, and the rest can be installed later. I’m not exactly sure what you mean by interior finishing, but that can surely be done over time as well. So, you could save money here initially. It’s not a lot, but it will certainly be more convenient for you now.
I think it came across that, in the end, I would do everything possible to get a full basement and prefer to postpone non-essential items, either doing them myself or having them done later.
I just looked into light wells. These seem to be available starting at around €70 (about $75), and according to online sources, the price of a basement window is around €100 (about $110), all without installation. So, it doesn’t cost that much more.
Please correct me if these prices are wrong.
Regarding the other items you mentioned, such as doors, interior finishing, etc., it is definitely possible to start on a tight budget. A light switch and a ceiling light don’t cost much, and the rest can be installed later. I’m not exactly sure what you mean by interior finishing, but that can surely be done over time as well. So, you could save money here initially. It’s not a lot, but it will certainly be more convenient for you now.
I think it came across that, in the end, I would do everything possible to get a full basement and prefer to postpone non-essential items, either doing them myself or having them done later.
B
Bauexperte14 Apr 2015 13:49Hello,
If you build a partial basement, you might save around 10K to 15K EUR (thousands of euros) at best. It’s less about windows, electrical work, or masonry; rather, a foundation may only be placed on undisturbed ground. This means the pit for the partial basement—including the working space—is excavated, then the basement floor is poured and the basement either built with masonry or as a concrete sandwich structure. After the necessary sealing and installation of a cavity membrane, the soil is backfilled and compacted, and that’s when costs rise. Because the soil where the ground floor slab will rest has already been disturbed, the ground must be properly prepared—this often involves stepped foundations (as stated in the geotechnical report). Only after this can the ground floor slab be poured; this requires more care than on sites where the basement floor and ground floor slab can be poured in one go. These are not cheap measures, and I’m not even mentioning further requirements if soil replacement is necessary.
On the other hand, a few extra bricks or sandwich panels don't cost much, and the additional concrete cost is negligible—except for one case. If a watertight foundation (“white tub”) must be built, more reinforcement steel and a stainless steel foundation earth conductor will be required. It’s basically just a calculation exercise; electrical installations and light shafts (unless you choose the Swiss variant) are negligible costs. After all, this is a utility basement, or are finishing costs already included in the 50K EUR? I tend to doubt that, but who knows... architects can be very creative with their calculations.
Best regards, Bauexperte
ezio80 schrieb:Your architect’s arguments are a bit off....
He estimates the cost for the partial basement at around 50K EUR. According to his calculation, a full basement would add another 40K EUR, so a total of 90K EUR for the full basement, which seems quite high to me. But according to that, there would be some potential savings in my opinion.
What do you think? Does anyone have experience with costs for partial or full basements?
If you build a partial basement, you might save around 10K to 15K EUR (thousands of euros) at best. It’s less about windows, electrical work, or masonry; rather, a foundation may only be placed on undisturbed ground. This means the pit for the partial basement—including the working space—is excavated, then the basement floor is poured and the basement either built with masonry or as a concrete sandwich structure. After the necessary sealing and installation of a cavity membrane, the soil is backfilled and compacted, and that’s when costs rise. Because the soil where the ground floor slab will rest has already been disturbed, the ground must be properly prepared—this often involves stepped foundations (as stated in the geotechnical report). Only after this can the ground floor slab be poured; this requires more care than on sites where the basement floor and ground floor slab can be poured in one go. These are not cheap measures, and I’m not even mentioning further requirements if soil replacement is necessary.
On the other hand, a few extra bricks or sandwich panels don't cost much, and the additional concrete cost is negligible—except for one case. If a watertight foundation (“white tub”) must be built, more reinforcement steel and a stainless steel foundation earth conductor will be required. It’s basically just a calculation exercise; electrical installations and light shafts (unless you choose the Swiss variant) are negligible costs. After all, this is a utility basement, or are finishing costs already included in the 50K EUR? I tend to doubt that, but who knows... architects can be very creative with their calculations.
Best regards, Bauexperte
S
Sebastian7915 Apr 2015 14:47We planned a full basement, and according to the architect’s estimate, it costs around 70,000 euros, which was at least accurate for the structural components. Excavation work costs less than 4,000 euros – no replacement needed, no groundwater pressure or rising damp issues.
The basement size is just under 80m² (860 sq ft), with approximately 40m² (430 sq ft) intended as living space.
By the way, windows cost about 300 euros each if you want something decent (proper handles, insulated).
The basement size is just under 80m² (860 sq ft), with approximately 40m² (430 sq ft) intended as living space.
By the way, windows cost about 300 euros each if you want something decent (proper handles, insulated).
B
Bauexperte15 Apr 2015 15:07Lexmaul79 schrieb:
By the way, windows cost just under 300 euros if you want something decent (proper handle, insulated). As I said; compared to the total construction costs, it’s rather negligible
Regards, Bauexperte
We paid around €58,000 for a 98 m² (1,055 ft²) basement area with 3 windows, 4 rooms (now 5, long live drywall), a straight concrete staircase, 8 cm (3 inches) perimeter insulation, a cantilevered basement ceiling with an Isokorb thermal break, and a protrusion / “basement bay” if you want to call it that, built as a “black tank” waterproofing system in a sandwich construction. Earthworks were, of course, not included.
We already found that quite expensive...
I believe the slab foundation was charged separately, at least in terms of cost.
Saving €40,000 seems absolutely unrealistic to me (which doesn’t mean a basement builder won’t still quote it...) As Bauexperte already explained, the foundation for the part without a basement is significantly more complex ---> and therefore more expensive.
We already found that quite expensive...
I believe the slab foundation was charged separately, at least in terms of cost.
Saving €40,000 seems absolutely unrealistic to me (which doesn’t mean a basement builder won’t still quote it...) As Bauexperte already explained, the foundation for the part without a basement is significantly more complex ---> and therefore more expensive.
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