Construction costs for a turnkey single-family house on a slope 2022

Thanks to you!

I have already dealt with the issue of the missing development plan a bit more intensively and have come to the conclusion that this "insertion" is quite clearly defined and should not pose an obstacle to the building style (provided there is no contradictory municipal statute). I am aware that employees at the building authorities may not feel bound by this, but the legal basis is the essential thing. Regarding the costs of the granny flat: how much higher do you estimate the price compared to an identically sized residential basement?

I have already dealt somewhat intensively with the topic of the missing development plan and have come to the conclusion that this "insertion" is quite clearly defined and should not pose an obstacle to the building style (provided there is no contrary ordinance from the municipality).

However, without a development plan, some anchor values are also missing – the determination of reference heights and the number of stories of the surrounding comparison houses in hillside locations is, to put it mildly, not trivial.

Regarding the costs of the granny flat: how much do you estimate the additional cost compared to an identically sized residential basement?

Completely independent of square meter construction costs, it is a truism that renting out in a batch size of one residential unit cannot be a business. You have to reckon that it will actually be neutral, but fiscally still a "profit," i.e. you effectively pay income tax on something that does not really make you richer.

However, without a development plan, some anchor values are also missing – the determination of reference heights and the number of floors of the surrounding comparison houses is, to put it mildly, not trivial on slopes.

Thanks for the hint! I haven’t dealt with that in detail yet; the immediate neighboring houses are quite tall and, according to my understanding, have the following structure: 1. Basement (ground level on the valley side), 2. Ground floor, 3. Upper floor, 4. Attic floor.

Completely independent of square meter construction costs, it is a truism that renting out a single housing unit cannot be a business. You have to expect that it will actually be neutral, but for tax purposes still a "profit," i.e., you effectively pay income tax on something that doesn’t actually make you richer.

Unfortunately, I still don’t quite understand that. What about the benefits? You can depreciate the purchase price for the granny flat annually for tax purposes when renting it out, generate rental income, and – if I am correctly informed – can apply for about 30,000 euros in subsidies. If you instead make a pure residential basement (with the same number of square meters), these benefits disappear completely. Don’t the additional construction costs have to be substantially higher for these benefits to become secondary again?

If you forgo a granny flat, you can use the basement for living space instead, allowing you to design your remaining living area smaller, since you can plan living rooms there yourself ... garden access or whatever. This means overall fewer square meters to build = lower costs.

Write something about your budget. Slope, Bauhaus style, window fronts, etc. you tick a box for all expensive things. 2,500€/m2 are not enough here. Currently, your project is certainly seven-figure. An architect with individual contracts is also recommended here and not a prefab house. Reasons against a granny flat have already been mentioned.

We have quite a bit of equity and could probably manage a sum of 1-1.5 million. Whether we want to fully utilize the financial scope is another question.

The reason for the Bauhaus style is also due to the peculiarities of the plot, which in turn is the prerequisite for being able to build at all. It is extremely difficult to find plots here anymore. I think a "conventional" single-family house simply doesn't look good visually under these conditions (steep slope, view). The question of architect-designed house vs. prefab house is certainly important, but here we are fixed for several reasons that we want everything as much as possible "from a single source," since we are, among other things, very time-restricted due to our professions and prefer a total sum rather than a plan where the trades end up differing significantly in the end.

@ rick2018: I have been following your project with great interest for months and it has certainly contributed to our favoring a Bauhaus style, although that would of course exceed the financial scope here. ;)