New single-family house 180m²

: I just gave some thought to this installation layer... OSB is actually diffusion-tight, right? If you then stuff the installation layer with insulation wool, won't it rot in there?[/QUOTE]


No, since the insulation in the installation layer is only 40-60mm thick, it has no impact

KfW55 shell,

Yes, does he guarantee that the house overall meets KfW55 standards?

What about the door blower test?

What about the construction site toilet?

Where is the KfW advisor/costs?

Is the exterior facade including the plinth?

Windows (plastic, white inside, foil-coated outside, triple glazing) and front door: €22,700

What is the security class of the windows and doors? If none is specified, often there are not even mushroom head locks...
Depending on the number of sashes, you can probably add another €7,500-15,000 for RC2! (without N; so laminated safety glass) for all ground floor windows, and depending on the attack vector also on the upper floor

Sanitary installation (3 sinks, 2 WCs, 2x walk-in showers, 1x bathtub): €13,500

How high is the tiling in the offer? 1.20 m?

: I don’t have a price for the foundation yet, it is listed in the offer as follows: For the static and frost-free foundation of the house, either gravel filling or footings under the slab are required. The amount, size, and height of the required gravel filling or footing can only be determined and offered after completion of the building application and exact site measurement.

And what about the soil survey? Already done?

12.5 mm gypsum fiber boards

That's very little. Even if fiber boards are better than gypsum plasterboard; but hanging heavier items solely on the gypsum fiber board... Better yet an OSB behind it, or at least double-layered, especially in the kitchen and living room walls.

The Fermacell PuV states for single fiber boards 12.5 mm, 30 kg load for screws and 50 kg for penetrating anchors. The restriction is that the load values can only be added if the anchors are 50 cm apart.

Thank you nightdancer for your kind advice and the detailed review of the offer. We are at the very beginning of our project and I am actually reading a lot about the topic of house building right now - maybe you even have a book recommendation, since you subtly hint that I am not a professional (by the way, I already knew that before your post...)?!

And thanks also to Sascha from H, that was exactly the intention. Of course, I am not so naive as to throw a house provider 350-400k in the throat without knowing exactly what I get for it. Hopefully, I will get several opinions/advice through a forum, well aware that these will not be the sole basis for a decision.

Thanks for the tip regarding the installation level. I will take that point on board and inform myself about the advantages and possible disadvantages and the additional costs.

Yes, does he guarantee that the house overall meets KfW55?

What about the Door-Blower-Test?

What about the construction site toilet?

Where is the KfW consultant/costs?

Is the exterior facade including the plinth?

What is the security class of the windows and doors? If none is specified, often there isn’t even mushroom cams...
Depending on the number of wings, you can probably calculate another 7,500-15,000 for RC2! (without N; so laminated safety glass) for all ground floor windows, and depending on the attack vector also on the upper floor.

How high is tiled in the offer? 1.20 m?

And what about the soil report? Already done?

Quite little. Even though fiberboard is better than gypsum board; but hanging heavier things on just the gypsum fiberboard... Better yet to have an OSB behind it, or at least double-layered, especially in kitchen and living room walls.

The fermacell PuV says for single fiberboard 12.5mm, 30kg load on screws and 50kg on through bolts. The limitation is that the load values can only be added if the dowels are 50cm apart.

Thank you for your comments:

[*]Blower-Door-Test: is included
[*]Construction toilet: is included
[*]Regarding KfW: at the moment only the shell is suitable for KfW55, the floor slab or insulation underneath is not. I have already noted this on my list of points to discuss.
[*]Yes, exterior plaster includes the plinth
[*]Security class of the windows: indeed nothing specified – thanks for the tip, I will note it.
[*]Soil report: not included – I have calculated €1000 in the additional costs for this
[*]Wall construction/gypsum fiberboards: thanks here as well, I will include it.

If the property is already owned, the soil survey should be done now and not only after signing.
What is supposed to be a KFW55-suitable shell? Either the building complies with KFW55 or not, if this funding program is to be used. Only that should be clear before signing the contract. Tiles - which sizes are included? Which installation method, etc. etc.

Regarding KfW: at the moment, only the shell is KfW55-compliant, the floor slab or the insulation underneath is not. I already have this on my list of points to discuss.

As nightdancer just wrote. The important thing is not whether the individual components are KfW55 suitable, but whether the provider currently stands and is also able to certify to the KfW Bank that the house as a whole achieves KfW55.

Security class of the windows: actually nothing specified - thanks for the tip, I’ll include that.

Don’t forget the security class of the door.

And have you already examined the standard; what is basically included as tiles / sanitary fixtures in the standard.