ᐅ Shell construction company builds basement smaller than in the approved building plans

Created on: 28 Jan 2023 21:18
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domino55
Hello everyone,

A shell construction company was commissioned to build the basement with in-situ concrete according to the existing factory plan (14.0 x 6.66 m (46 ft x 21.8 ft)). However, the company missed the dimensions and built the basement about 4 cm (1.6 inches) smaller. This applies to both the exterior and interior measurements.

Dimensions according to factory plan
Target house width: 6.66 m (21.8 ft)
Target width of basement concrete walls exterior: 6.525 m (21.4 ft)
Target width of basement concrete walls interior: 6.025 m (19.8 ft)

Actual width of basement concrete walls exterior: 6.48 m (21.3 ft) (-0.04 m (-1.6 inches))
Actual width of basement concrete walls interior: 5.96 m (19.6 ft) (-0.06 m (-2.4 inches))

I measured myself using various tape measures and a laser distance meter.

What should be done in this situation?
Price reduction due to smaller total area? If so, how much? Are there any standard tables or guidelines for this?

It is especially unfortunate that the house was built smaller on the narrow side (maximum size restricted by the zoning/land-use plan), where every centimeter counts.
This also has consequences such as the possible need to adjust the factory plan (staircase, adjacent walls, support columns no longer fit).

Best regards

Cross-section of basement: concrete basement walls, interior dimension, sound insulation, waterproofing.
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Tassimat
28 Jan 2023 22:42
WilderSueden schrieb:

And that means 1–3cm (0.4–1.2 inches) of plaster will still be applied to the walls, depending on the mason’s daily performance and the plasterer’s mood 😉
How is the bathroom entrance door planned? If the plasterer applies a thick layer, possibly with tiles on the wall as well... will a door frame still fit with a rough opening of 6cm (2.4 inches)?
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ypg
28 Jan 2023 23:24
domino55 schrieb:

What should be done here?
Make a note of it with the construction company, your contractual partner. Compensation payments for this are rare, and if any, usually not enough to go out for steak and champagne with four people since it’s not really a serious issue. Ask them for a goodwill gesture, for example, lockable windows, better window sills, or a built-in closet.
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NatureSys
29 Jan 2023 00:08
Does the house really have to be smaller because the basement is smaller? Or can it be adjusted so that the ground floor maintains its planned size?
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Sunshine387
29 Jan 2023 00:18
I also find this deviation quite severe. On our build, the masons worked precisely down to the millimeter, and all measurements were accurate. This is especially important when building setbacks need to be maintained. In your case, it might not be a problem, but imagine if too much was built into the setback area—that would be a disaster. That’s why I understand why you’re rightly upset. However, whether the effort is worth it once the basement is already in place, I believe the answer is clear. No, definitely not.
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domino55
29 Jan 2023 01:47
WilderSueden schrieb:

The staircase manufacturer will come anyway to take the measurements and then build them according to the actual dimensions
These are concrete staircases that need to be ordered in advance based on precise measurements; otherwise, you lose a lot of unnecessary time.
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domino55
29 Jan 2023 01:55
11ant schrieb:

Who issued the contract, who hired the contractor, and who exactly are you (owner, buyer)?

The drawing refers to the neighboring building on one hand as an existing structure, but it looks to me more like a simultaneously built "opposing semi-detached house." One and a half centimeters (sheet ???) of insulation in between will never line up perfectly between planned and actual conditions, unless the neighboring house was built by watchmakers.

We know far too little about your construction project to offer detailed advice. But honestly, I rather get the impression you are looking for support in quantifying a claim for a price reduction.

I am the owner and I hired the basement construction company. I will either continue building myself or hire another construction company. The neighboring semi-detached house is completed and inhabited.
The insulation between the semi-detached houses is 2 cm (about 0.8 inches) from each side (4 cm (about 1.6 inches) total), but it is compressed by the in-situ concrete. However, this does not matter because the corners were probably simply staked out incorrectly. The construction company did this themselves without a surveyor.
I cannot imagine that this defect can be corrected in any way. That is why I am concerned with properly quantifying the damage.