Construction costs for a single-family house with a basement (KFW 55)

Hello everyone in the community,

in the past, we have noticed that this forum brings up many great ideas and has very many helpful members. For this reason, we recently registered as well.

A brief introduction about us: My partner and I live in Oberhausen in the sunny Ruhr area.
We have (not yet) built and are currently in the planning phase.

The first sketches have already been created and amount to:

Basement: 70.75 m² (livable finished)
Ground floor: 81 m²
Upper floor: 70.75 m²

Rough cost estimate according to the architect as excerpt:

- The (roughly calculated) costs amount to 334,800 Euro.
- In addition, the garage +5000 Euro
- The conservatory +8000 Euro
- The foundation for the extension +2500 Euro
- The shredder for WC in basement +3000 Euro
- The basement plaster +3000 Euro
- The WC in basement +5000 Euro
- The total costs amount to approximately 361,500 Euro.

Desired features: shell-ready, KfW 55, controlled residential ventilation, air-to-water heat pump, photovoltaic
Structure: 1 1/2-storey in solid construction with brick veneer and gable roof (without bay window)

Additionally, we must say that the plot (600 m²) is already available to us through inheritance.

To be honest: we have calculated (due to the existing plot) less.
Perhaps we are just too naive here.

Does the cost framework correspond with your experiences for the above living area with basement?

If further information is needed, just ask.

Thank you in advance for your opinions!

Regards
Kristine & Markus

Welcome to the forum...

We are currently also in the detailed planning phase. Dreams and reality.

Try really to go as deep into detail as possible, our planning is already 3 pages long and still many ??. Always also pay attention to net and gross. Are all ancillary construction costs included? Buffer calculated? Offer from the architect included? 5,000 euros garage, what is that supposed to be, paved area with a tarp?

If you are currently creating sketches, there is still no building permit and soil survey available.

Without really going into detail now, but with 220 sqm living space, KfW 55, living basement and solid construction, a big 4 will stand at the end. So don't just plan downward, expect the whole project to become more expensive.

Thank you for the feedback.

A small addition:

The basement is not intended to be used as regular living space.
We were thinking more of a guest room and a hobby room here.

In general, the basement is considered by us as a utility or storage area for technical equipment and "laundry".

The basement is not supposed to be fundamentally used as living space. We were thinking more of a guest room and a hobby room here.

Then your architect has certainly factored in a storey increase. Since you plan to build according to KfW 55 standard and the basement therefore has to be within the insulated envelope anyway, finishing *only* 2 rooms doesn’t really make sense. The "little bit" of underfloor heating and proper windows won’t make much difference then. If by "turnkey" you mean without painting and flooring work, I really like your architect’s calculation. You just must not forget that this calculation refers purely to the house structure plus a prefabricated garage 3.00 x 6.00 m. There will still be considerable additional construction costs, such as costs for outdoor facilities ... and if my assessment is correct, also costs for painting and flooring. Rhenish greetings from on the road

This is my calculation for a house with a floor area of 9.5 x 11.5 meters:

Shell construction: €165,000.00
Windows: €15,000.00
Doors: €8,500.00
Stove: €10,000.00
Garage including foundation and crane: €22,000.00
Garage roof: €0.00 (flat roof)
Earthworks: €8,000.00
Tiles: €8,000.00
Parquet flooring: €8,000.00
Painting work: €5,000.00
Electrical installation: €12,802.02
Nibe F-1255-6 €7,000.00
Heat pump installation: €2,500.00
Ground loop kit: €1,500.00
Underfloor heating: €10,519.60
Cold and hot water pipes: €3,589.04
Bathroom plaster work: €852.04
Drain and connection pipes: €1,404.20
Controlled residential ventilation: €9,610.62
Photovoltaic system: €18,500.00 (incl. battery storage)
Kitchen: €15,000.00
Connection costs: €8,000.00
Bathroom equipment: €15,000.00
Garden: €15,000.00
Total: €370,777.52

However, many tasks are done by myself. Including a buffer, I currently estimate about €400,000. The house will be built with Ytong (36.5 cm wall thickness, possibly even 42.5 cm).