Rough construction cost estimate single-family house

Hello everyone,

we are planning to build a single-family house soon. Therefore, I wanted to ask you whether my rough cost calculation makes sense or if I have forgotten something.
Key data: Basement, ground floor, upper floor (approx. 90 sqm per floor), double garage, hip roof, air heat pump, photovoltaic system with storage in solid construction.
Basement: technical room, hobby room, utility room, storage room
Ground floor: open dining room, living room and kitchen, vestibule, staircase, pantry, guest toilet
Upper floor: study, bathroom, bedroom, dressing room
Construction site: Bavaria, northern Upper Palatinate
If I have forgotten important key data, I will gladly provide it afterwards.
The kitchen does not usually belong in the construction cost calculation, but all other furniture is already available and I want to consider all costs.

Cost calculation:

Trade	Cost Calculation	Comment
Shell construction + basement	€300,000.00	Construction helpers
Plastering inside + outside	€30,000.00	Construction helpers
Screed	€10,000.00	Construction helpers
Development	€15,000.00	Land developed, except for lowered curb
Additional construction costs	€20,000.00
Heating + ventilation system	€30,000.00
Photovoltaic system with storage	€20,000.00
Electricity	€8,000.00	Mostly own work, trained industrial electrician
Sanitary	€20,000.00
Tiler + tiles	€10,000.00	Bathroom, utility room, technical room, guest toilet
Front door	€5,000.00
Windows	€25,000.00
Floors	€10,000.00	Own work, material only
Ceilings	€10,000.00	Own work, material only
Interior finishing miscellaneous	€5,000.00
Interior doors	€10,000.00
Garden + outdoor facilities	€10,000.00	Own work after construction
Kitchen	€25,000.00
Terrace	€10,000.00	Own work after construction
Roof + covering etc.	€50,000.00
Garage	€20,000.00
Painter outside	€15,000.00
Painter inside	€1,000.00	Own work, material only
Stairs	€20,000.00
Total	€763,000.00
- Own work 10%	€686,700.00	About 1000 hours possible through overtime + additionally wife + father own work possible
Land	€84,000.00	Additional costs already included
Total	€770,700.00

Where have I estimated too low, where perhaps too high?
This is just a list from me without having obtained any offers.
The own work as construction helpers has been deducted overall at the bottom and was not subtracted from the individual trades.
Thank you very much in advance for your opinions.

As you have calculated, the offers will tell you later. A flat rate of €3,000/sqm living space is calculated for pure construction costs. Bavaria and simpler own constructions can make it more expensive. Then there is the basement. Residential basement or utility basement. And garage, terrace, driveway, outdoor facilities. And additional construction costs.

You have set your own contributions at over €70 / hour. For that, I can also hire a craftsman on an hourly basis, but he works significantly faster than you. From my perspective, the own contributions are calculated too high.

You should provide information about the location and building and at least a basic floor plan idea so that the individual items can be assessed in terms of their weighting. Otherwise, you can only use the above-mentioned rule of thumb. If you actually derive added value from it yourself, that is good for you, but I would rather not factor it in. As I see it, you have deducted the own contribution twice by stating "material only, since own contribution" for multiple items, but then additionally charged €77,000 as own contribution at the end, didn't you?

yes, I have also already calculated with €3000 per sqm. that's true, I deducted those twice. I have to look at that again and then I will come closer to around €3k per sqm. So a total of €810k. yes, I also need to calculate lower there. I had never calculated the hourly wage the other way around before. Here is still our rough floor plan idea. We are building in a rural area. The designs are only do-it-yourself. The plot also has a slight slope.

You have everything that causes costs with the house - we don't want to talk about the planning and the floor plan here -
- hillside location
- windows
- bay window
- roof due to/floor plan and roof shape

I would calculate larger than 3,000€/sqm (so over 540k pure construction costs for the house), plus 75k for the basement (pure cold utility basement, as a living basement with heating around 200k), at least 50k for the garage plus ancillary construction costs and outdoor facilities/terrace etc.

As a complete package, you should still keep a decent buffer in your calculation.