ᐅ Offer for Ytong Prefabricated House Kit / Construction on Existing Basement

Hello everyone, I’m new here 🙂,

We are currently in the process of demolishing an old prefabricated house on a plot we purchased, down to the basement, and plan to build a new house on top of that basement.

We are very interested in a Ytong kit house, but unfortunately, we have no clear idea about the price range. Therefore, we would really appreciate it if someone knowledgeable could roughly assess it.

The construction is planned to take place in southern Baden-Württemberg.

Here is the offer we received:
House dimensions 10 x 9m (33 x 29.5 ft) + extension 5.5 x 4m (18 x 13 ft) (living area estimated at 150m² (1,615 ft²))
Gable roof 38°
Knee wall 1m (3.3 ft) with 2 dormers over 2/3 of the length
KfW 55 standard

--> Concrete slab for the conservatory extension
--> Stainless steel chimney
--> Exterior walls of the living floor + ceiling
--> Roof structure including covering, insulation, and drainage
--> Attic ladder + stairs from ground floor to upper floor
--> PVC windows + roller shutters (€34,500)

Total price €139,000 (of course, almost everything is planned as self-construction, except for complex steps such as roof structure, ceilings, concrete slab... with some assistance)

Can anyone estimate whether this is cheap or expensive?
Would it be possible to get a shell construction (structure only) without self-construction for this price?

If you have any questions, feel free to ask 🙂

Thanks a lot in advance.

Best regards