Construction company wanted in the Stuttgart metropolitan area!

the cardboard box with pressed wood walls and Fleischkäse

what is that supposed to be?

No idea, you tell me

We have just reached an exciting point because we are currently also considering the building material. More on that later, but first, an update.

I will summarize the experiences already written here – see post #86 for details.

Prefabricated House / Timber Construction

[*]Bittermann & Weiss -> Offer received | the price is about 20,000 euros above the previous average. However, many special features are included, including design elements, etc. Currently, we are leaning more towards a solid house. However, I can pass on to everyone else that B&W really put a lot of effort into it and the offer is quite detailed and transparent. You get your own plans and, as mentioned, a detailed price breakdown with individual prices. The price was very high at the beginning, but many special features were already included that we did not need and then removed. So don’t be alarmed at the beginning.
[*]Talbau Haus -> Eliminated | Reason to follow
[*]Hanse Haus -> Eliminated | Overall impression / gut feeling
[*]Bien-Zenker -> Eliminated | due to differences
[*]Prefabricated House Weiss -> excluded
[*]Schwabenhaus -> excluded/terminated
[*]Albert Haus -> postponed

Solid House Providers

[*]Haus der Handwerker -> Offer received | so far the cheapest offer regarding equipment. Construction with 24cm T16 brick and 14cm ETICS
[*]Hauser Massivbau -> Offer received | the price is slightly below the previous average. The standard equipment looks good. Will definitely be shortlisted. Construction with Liapor prefab walls.
[*]Köhler Wildberg -> Appointment took place | we were once again explained how the price is generally composed with very good transparency. However, no statement about our construction project is possible without architectural planning. We currently have a good gut feeling here, apart from the price issue. Construction with Ytong PP2 36.5cm outside and sand-lime brick inside.
[*]AWS -> Offer received & eliminated | Price is about 50,000 euros above the average price, adjusted for equipment, etc. Therefore, unfortunately excluded, even though the quality is certainly very good and the contact was positive. Construction with Poroton bricks (e.g., Thermoplan T8 or S8) and interior walls 10cm gypsum wall panels (raw density 1,200kg/m³)
[*]U-Haus -> Offer still pending | Construction with aerated concrete 36.5cm
[*]FERMO -> excluded - significantly too expensive
[*]Härtter Renningen -> Rejection by Härtter due to capacity

Currently, we still have three providers under consideration, with whom we have a good gut feeling. Aside from the later decision based on gut feeling / price / etc., we have two providers with completely different building materials and concepts. Now I have tried to objectively evaluate the building materials to determine which variant is better for us. Somehow, I can't come to a conclusion. In general, I am open to an ETICS, so I have no reservations against Styrofoam.

Hauser
Outside: Liapor prefabricated wall 14cm + 17cm Styrofoam external insulation
Inside: Liapor prefabricated wall 14cm (possibly partly concrete prefabricated wall if statically required)
Floor slab 25cm
Clear shell construction height 2.67m - finished room height approx. 2.45m (13cm suspended ceiling for electrical installation)

Advantages:
+ High own weight of the wall with high sound insulation (unfortunately no values known)
+ Exterior wall approx. 5cm thinner (31cm), but does that really help?
+ Better thermal insulation due to ETICS? (unfortunately no values known)
+ Suspended ceiling allows subsequent changes
+ Lower error tolerance due to prefabrication in the factory with corresponding computer and measurement technology

Disadvantages:
- Does a high own weight of the wall lead to problems with subsequent modifications or drilling holes?
- Mandatory suspended ceiling leads to slightly lower room height
- Individual reports mention possible thermal bridges at the joint edges of the prefabricated elements
- External Styrofoam insulation could develop algae?
- Installation of double-glazed windows (overall U-value 1.0)?

Köhler (and U-Haus similar)
Outside: Ytong aerated concrete ThermStandard PP2-0.35 with 0.09 lambda
Inside: Silka sand-lime brick
Floor slab: 22cm
Clear shell construction height: 2.65m - finished room height approx. 2.50m

Advantages:
+ High interior mass with good sound insulation
+ Proven construction type and building material
+ Slightly higher room height

Disadvantages:
- Worse sound insulation of exterior wall (47.5 dB), although here the windows are probably the bigger problem?
- Individual reports of "crumbly" building material? Is that really the case? Does that cause problems when drilling holes, etc.?
- Potentially higher error tolerance due to on-site construction

Have I forgotten or possibly misattributed any pro or con points?
As mentioned, I really want to first try to find objective aspects and then try to evaluate which building material or building concept is better for us.

(unfortunately no values known)

(unfortunately no value known)

but does that really bring anything?

You have already decided anyway... you list the above under "+" even though you yourself say you have no idea or there are no values, with the competitor you list values like dB as a disadvantage even though no comparison with Hauser is possible... why? What do you want to achieve with that? I therefore refer to the first sentence: you have long since decided, no matter what you say now.

We had the same considerations. I don’t want to preempt anything for you, the decision is yours to make, but perhaps as an addition:

For sound insulation, take a look at this table: Schallschutz Außenwand Ytong

You can see that it is mainly, almost only, influenced by the windows. For a better feeling, you can easily use the PP4 with a bulk density of 0.50 instead of PP2 with 0.35, which really makes a difference. With that, you are also significantly better off than Poroton T9. Whether U-Haus has the P4 or an equivalent, I doubt it. As far as I know, they only have their own large-format blocks, just P2 0.35.

Poroton is also crumbly, but I find the styrofoam issue with Liapor more problematic, especially for exterior use with special dowels, spacers, etc. If Hauser had monolithic Liapor for the exterior, it would have been his choice with us.