Cost estimation for basement in near shell construction

Hello,

I am planning a basement and wondering what costs approximately will arise.
-> Excavation work excluded

The key data of the basement are as follows:
- approx. 90 sqm of usable area covered with screed
- of the 90 sqm approx. 40 sqm with underfloor heating (directly next to the heating room) - no floor covering
- No interior plaster, no exterior plaster - shell construction
- KFW40 basement

It would be optimal if you could tell me approximately what the individual items cost,
but an overall estimate would also be helpful.

If any information is missing, please ask, I will then provide more details.

Thank you very much.

The shell construction of the basement is mainly influenced by the following points: intended construction method (cast-in-place concrete, precast elements)? Water exposure class? Room height? Electrical installation surface mounted or flush mounted? Concrete staircase included or excluded? Number of windows / light wells? Number of interior walls? Depending on this, you can expect costs between €750 and €900 / sqm for the shell construction.

Sealing membrane floor: approx. €5 / sqm
Insulation (depending on requirements & wishes): €15-20 / sqm
Underfloor heating: €25-30 / sqm
Screed approx. €22 / sqm

For "KfW40" it will certainly be relevant whether and how the basement area has to be connected to the controlled residential ventilation system – you may need to plan for additional costs for the ventilation installation.

Perfect. Thanks for the assessment. I come to about 87,000 EUR with your details. Can you tell me what would be added if the basement were to be constructed as a [Weiße Wanne]? The property is on a slope (about 10%). To estimate the worst-case scenario, I would include the [Weiße Wanne].

You only get a binding price from specialist companies.

I am less concerned about a binding price. My primary goal is to get an assessment / overview.

Building a basement in passive house standard on a slope. 90 sqm. WU concrete + bitumen coating. Later room height approx. 2.50m. Walls made of in-situ concrete. Prefabricated ceilings and ready-made stairs. Two terrace doors and three fixed glass elements. About 60-70% of the basement is underground. Shell construction costs are approx. €115,000 gross including complete insulation - excluding civil engineering work. Contract award was February 2023. As a reference for you.

Best regards