Assessment & assistance semi-detached house, approx. 180 sqm in DIY floor plan

Hello again everyone :9

The last two weeks have been very intense. We spoke again with all the providers to narrow it down to three. The floor plan was optimized again (stairs, attic, etc.), but has actually taken a bit of a backseat. We now want to revisit this.

Now we have 3 offers that couldn’t be more different. For the "same" house (sometimes more, sometimes less), there is a price range from 480TEUR to 680TEUR. Can someone give me a tip on how I can make them comparable? I have now started to create a detailed Excel and immediately noticed points like the thickness of the floor slab, earthworks, etc. Two of the candidates build with lightweight expanded clay aggregate, one says that 42.5cm would be analogous to the KFW55 standard, and that a ventilation system is not needed (however, I pulled it out of him that there is indeed window-plant ventilation - leaves a bad taste), the other lightweight expanded clay aggregate provider was quite surprised and asked how that should work. He can only manage an ex-KFW 55 standard with 49cm walls.

We are now a bit torn back and forth, the cheapest provider builds 42.5cm, which would of course also be a gain in living space. However, distant acquaintances also bought a house from that salesman 10 years ago and shared experiences with us that unfortunately suggest that communication here is not entirely honest. We want to avoid surprises that become expensive by saving 200k. I also have a bad feeling when it is too cheap.

Nothing from you has arrived for me yet, not even in the spam suspicion folder.

Oh, sorry, I thought no one had replied in the thread anymore and just saw it now. Should I write to you privately? Or am I missing something :oops: :rolleyes:

For the sake of completeness, here are the revised DIY floor plans. The providers have for the most part now adopted them as well. But I do not have them here because they keep being taken away :rolleyes::rolleyes:

I always find Katja's suggestions very good, but in my specific case, a study room would be missing on the upper floor.

For the "same" house (sometimes more, sometimes less) there is a price range from 480K EUR to 680K EUR. Can someone give me a tip on how I can make this comparable?

Compare the construction and service descriptions.
This will be an activity that fills several evenings. Additionally, pay attention to what is not included, or what is the client’s responsibility.

Alternatively: Bring in expertise (e.g., an architect).

A lot has already been said about the floor plans, I still don’t find them successful (stairs, hallway, attic, ...).

Now we have 3 offers that couldn’t be more different. For the "same" house (more or less) there is a price range from 480TEUR to 680TEUR. Can someone give me a tip on how I can make this comparable? I have now started creating a detailed Excel sheet

Excel tables for comparing various points that cannot be purely represented parametrically or the inevitable supplementing with additional comment fields are the best way to “further develop” an apple-to-orange comparison beyond "only the d***s cut from sums." Better is to actively specify the comparison criteria. It’s no rocket science, but I do it faster myself than explaining it to beginners.

Should I write to you privately? Or am I missing something

For that, I had repeatedly invited you, and interpreted your words

Hi, it's me

as if you had written to me, and then found nothing in my inbox (name as here, at gmx de).

I always find Katja’s suggestions very good, but in my specific case a study would be missing on the upper floor.

I don’t quite understand now. The office is on the upper floor, do you need two? Or is the attic not being converted?

The providers have for the most part now also adopted it that way.

Oh dear, whoever you choose, please have proper designs made by an architect. I don’t want to speak ill of your dedication but you want to end up with something decent for your money after all.