Single-family house with a granny flat on a 450 sqm hillside plot

One could also ask whether individual rooms could be excluded from the floor area ratio - for example HAR and stairs. Maybe they could be persuaded with a tearful eye and four children under their arm?

I imagine that even , with one more child and a stronger tendency, would have managed without exemption.

I imagine even with one more child and a stronger tendency would have managed without exemption.

The decisive factor is the floor area ratio of 0.4 on 450 sqm. Does Arifas have similar requirements?

Thank you very much for your contributions. I was able to take away some suggestions and also learned how important the floor area ratio is.

You are an expert, given how quickly you come up with drafts here. Many thanks!

The draft refinement is service phase 3 and thus anyway only 2/3 of the amount for service phase 5.

here it slipped in during my morning half-sleep. We spent 3000 euros on the planning. Never mind.

Assuming we calculated with 480k, then adjusting would mean going from the 620k offer price to a draft that is 48/72 in size (meaning one third smaller).

If we decide for the cheaper offer, that is for the developer with the 540 euro offer, then according to this calculation only a 12 percent area reduction would be necessary.
However, since the budgeted income from the granny flat must also be taken into account, the draft would probably have to be significantly more compact than this 12 percent reduction.

Right, you’re completely missing the point. It was about the fact that families with double the average number of children can expect a fruitless search when they sift through the house suppliers’ catalogs for suitable models, and understandably then resort to self-designed plans; on the other hand, catalog designs with two apartments also offer two by two children’s rooms, two bathrooms, etc., without many changes. If only minor modifications are needed, the catalog model is just as effective a way to build cost-consciously as “giving up” bay window frills. I would never recommend an appendix with sugar-coated rental potential – from my point of view, that’s a bug, not a feature.

Now you’ve pulled me off the hook. Thanks.
Perhaps looking into the house offerings of the major prefabricated house companies would indeed be valuable in this respect. So far, we have rather looked at companies that build about 100 to 200 houses per year. There is rarely a large standard house offering there. But you can’t have everything. Especially not with a limiting budget.

You are an expert, judging by how quickly you come up with the drafts here. Many thanks!

That should of course have been "an expert in the field"

I’m afraid your financing plan won’t work like that. First of all, this whole [Einliegerwohnung] discussion – it’s been done a thousand times. Please use the search function for this. You cannot generate income from it during your lifetime. The construction costs almost always exceed the possible profit. In order for you to be able to build at all, you need to focus on the essentials. The offers from companies are hardly any cheaper with other providers. The current offers are almost always underestimated. Often additional costs arise, which you should keep as a buffer. Roughly calculated, I come to the following calculation: 550K budget of which 70K slope / outdoor facilities 450K house 30K buffer 450K / 2.8K/sqm ~ 160sqm I would therefore request offers for houses of about 160sqm.