Self-contained apartment above the garage

Hello

I have a question. Is it possible to build a granny flat on a prefabricated garage? We built one a year ago so that there is enough space for us and the children. Now we need more space because my mother-in-law is supposed to come to live with us. There is no space in the house and it is better for family life if everyone has a separate entrance and retreat place. If this is possible, how much does it cost and who does such work.

So, I think the proper foundation is missing and structurally the garage won't hold up either. Also: where is the garage located? At the boundary? That probably won't get approved. What is supposed to be on top? Maybe a 6 x 6 garage, with a small roof and a staircase for the mother-in-law... where is the living value and how many square meters?

In principle, you need a building permit to build. If you now want to use the garage + extension or only the extension as living space, you must submit a building application to your municipality. This is connected with: You need an architect (or an equally qualified authorized signatory), plans, static calculations, etc. To avoid having to present everything right away, there are so-called preliminary building inquiries. These can be submitted quite informally (so a rough sketch and site plan should suffice). Then it will be decided whether the project can generally be approved. As the very first step, you should call or visit the responsible building authority and discuss your concerns with the staff there. They can quickly give you an indication of whether it would be possible for you or not.

The garage is a prefabricated garage 3x7, so 21 sqm. Yes, I had already thought that there would be problems with the statics. Our garage is directly next to our neighbors' garage. I also thought about having a tiny house put on top of it. Another neighbor here on the street has an extension on the garage, it doesn’t look bad, only he planned it during construction, which we didn’t. We also thought that mother-in-law would move in with the older son, they have much more space. But she doesn’t want that, she wants to be with us and now we somehow have to find a solution. You probably know that too: family is nice and all, but you also need a place to retreat. I have lived with my mother-in-law before and that was certainly not easy.

Also: where is the garage located? At the border? Then it probably won’t get approval.

Our garage is directly next to our neighbors' garage.

ypg has already mentioned, besides the structural engineering, etc., one of the main problems. Compliance with the minimum distance requirements. If your garage is directly next to the neighbor’s garage, it was built on the property line. However, a house (living space) must maintain the minimum distance to the neighboring property (to my knowledge 3.00 m). This applies even if, for example, the roof of the garage is intended to be used as a terrace. Getting approval for such an expansion will be very, very difficult and probably (if at all) will take a very long time.
OK – advantage for you at that moment: mother-in-law can still wait a bit before arriving . OK – bad joke (I’m a fan of Al Bundy, after all).