Rough construction cost estimate single-family house

You designed the house for 2 people. For that, plenty of luxury in the basement. The house is neither beautiful nor efficiently buildable like this. For your calculated sum, something nice can be built. But the house should not be built like this. Roughly, you have 240m2 living/usable space with the basement 240*3300 = 792k + garage and outdoor facilities. Do you have a plan with the terrain heights?

Drafts are only do-it-yourself.

You better leave that at home when you go to the architect (without quotation marks!). You surely have other qualities.

In my opinion, you are going about a budget estimate clumsily. You don’t need such a thoroughly declined individually planned house model as a dummy, but certainly the expensive details of it, of which here the wind catcher bay window and the dining bay window (the latter becomes especially expensive with the roof construction) stand out to me.

Find a suitable similar catalog house and describe what you would like to change about it (e.g. these two bay windows or whatever else is important to you). Your calculation is nonsense without sauce: If the "shell plus basement" (what does "construction helper" mean here?) is a black box of roughly 300k flat rate, then it is completely pointless to add individual trades "accurate to the thousand". "Only fools cut sums": the plausibility of a sum of flat x or y tenths of a million plus a, b, or c individual thousands is practically hardly verifiable.

Show the plot with concrete dimensions (especially as many elevation points as possible), then at least an essential item (basement or other terrain improvements) can be assessed reliably. The 11ant basement rule will help you with that, among other things (externally, found in quotation marks as "With or without basement: a rule as a decision tool"). Other major items are the energy standard and the heating and hot water technology; followed by the building body (compact except for the bay windows in the example) including the roof construction, and then the equipment standard.

Your item list includes many ambiguities: for example, sanitary/tiles: do you mean by "in the bathrooms" only the sanitary ceramics, and then the tiles separately under "tiles," or does the separate item "tiles" only refer to, for example, floor coverings also from non-wet rooms?

Besides, I also recommend my "House construction roadmap, also for you: the phase model of the HOAI!" and here in the forum my posts on the keywords individual contracting / self-contracting and Gerddieter as well as to hire your architect including the only seemingly expensive service phase 5. Tell me more about yourself and your plot, with the completed questionnaire – it seems to me you could use more support than just "price fits / doesn’t fit."

Where is your price calculation for the architect, structural engineer, and energy consultant? What insulation standard do you want to achieve? Of course, style is a matter of debate and it has to appeal to you, but houses like that were built in Ireland in the 90s. We are also two people and built very spaciously and comfortably, but I can't make sense of what you showed, also because I don't know the life plan behind it. It is simply not possible to seriously comment on a floor plan without knowing the personal needs and backgrounds. But even with this knowledge, the bathroom on the upper floor is only large with a dance floor in the middle and something always hangs on the edge. The entrance to the shower is rather tight, even though there is plenty of space available. The open-plan room with just under 70 sqm can be nicely designed, but why don't you also have a proper bathroom on the ground floor, so that you (when older) don't necessarily have to go upstairs to shower? A mini pantry, if at all; the dimensions of the stairs can't be right like that, a huge hallway upstairs and also in the basement, which I see no point in given the expected costs, plus again a huge bathroom in the basement. This will be expensive, despite construction helpers, and for that I would rather look for a capable architect who makes the whole thing more compact yet comfortable and tailored to my (whichever) life. The design has so many fundamental flaws that you should recognize that another competent person needs to take over. You can certainly apply your skills elsewhere.

Commenting seriously on a floor plan without knowing the personal needs and backgrounds is simply not possible. [...] The design has so many fundamental flaws that you should realize that a different, competent person needs to handle it. You can certainly contribute your skills elsewhere.

The design is not up for discussion in this thread in terms of its planning quality (which is why I did not address it). What is essential (for the purposes of this thread) is that the design is unsuitable as a costing dummy and therefore the design effort invested in it does not generate any value. That it still leaves something to be desired in terms of planning is another matter. Currently, it is first and foremost about a costing dummy, which, as I explained earlier, should be purposefully "constructed" differently and also does not require a detailed, artistically refined form.

Referring to the 2024 Energy Saving Ordinance, I'll comment on your prices. -Structural work should be possible for less -I think the plastering outside and inside is too low, whereas I consider your exterior painting work too high, it could balance out -Electrical only material costs 8k with low demands -Development means wastewater, fresh water, and electricity from the street to the property? This may be possible, depending on the property, otherwise more -Heating + ventilation will be very, very tight with 30k, at least if everything is subcontracted -Sanitary including ceramics? Then rather tight budget -Does the tiler still have to tile the stairs? 10k is probably too little even without the stairs -Are the windows including shading, if yes probably too little as well -What do you want to do with the 10k for the ceilings? Plastering, suspending, filling? -1000€ for interior paint and acrylic is also not enough; it’s rather 2-3k Earthworks strongly depend on the property. Hard to say from afar. With a basement, it certainly won’t be much cheaper than 15-20k€ if everything is through a company and landfill.

Thank you very much for your answers. That has already helped me a lot. We are still in a very early phase and the self-drawn plan will certainly not be implemented as is, professionals will of course be involved. Yes, the cost breakdown, I have to agree with you, especially 11ant, is of course total nonsense. Planning the calculation down to the smallest detail does not work in this early planning phase. We overshot the mark or started incorrectly. We just wanted to roughly outline a direction for ourselves, whether we need to budget 700k, 800k, or 900k.

I have already read quite a bit here in recent weeks, but I still have to read some important things. I would use the completed questionnaire at a later date, once we have been to an architect or planner of a construction company.

Here is the plot with the elevations. The terrain slopes evenly from the north in all directions. Elevations come from the BayernAtlas, as we do not yet have a plan from the cadastral or surveying office.