Feasibility of a DIY house using timber frame construction

Dear community,

first of all, hello from my side. I am facing a possible project but unfortunately still have very little knowledge in this area. I was able to google a lot of general information, but overall I have quite little understanding.

Plan: I would like to build two small houses (each about 50sqm) using timber frame construction on a plot of about 1000sqm and use them as living space (primary or secondary residence). The foundation is to be a simple concrete foundation. For sewage disposal, I have thought about solving the whole thing with a small biological sewage treatment plant. Electricity would have to be connected (in an emergency it could also be generated otherwise). Supply should be largely self-sufficient with wood from our own forest, fruit/vegetables from our own cultivation, chickens, etc.

So in short, it is about inheriting a plot of land. The reasons for this at first glance rather utopian idea are beside the point, but they exist. In general, as you can already tell, it is not supposed to be a fully modern single-family house but rather something in the direction of a tiny house/DIY and should be actively inhabited for the next 7-8 years. My partner in this project has an active architect in the family who would also be involved in this project, which should also be relevant.

My questions:
1. Is living in this type of house generally allowed?

2. We do not know exactly whether the land is even building land and connected to utilities. Is it possible to get approval for a "self-sufficiency hut" without electricity and with a small sewage treatment plant? If not, what options do we have and what would it roughly cost us?

3. What exactly does the application process look like here if we start with a meadow plot and want to implement the project on it?

4. Assuming we have building land. Is the project possible and what does the application process look like?

It is important to me to emphasize that we do not want to lead a purely off-grid life and will pursue a normal job. Financially, we currently have about 80,000 in total with an option for 100,000 with a private loan (which we would rather avoid).

Thank you very much for your answers
Best regards and have a nice evening

2. We do not know exactly whether the plot is even building land and developed.

Then find out!

To me, it reads as if it were outdoor space, and you would only have a chance with agricultural or nature-related business, for example, you could grow organic vegetables to sell or breed dogs. However, 1000 sqm is not really much.

If not, what options do we have

Wait 15-20 years after applying to be allowed to build on the plot.

4. Assuming we have building land. Is the project possible and what does the application process look like?

I would just submit a building inquiry. For example, even septic tanks require a building permit.
If you want to build with a concrete slab, the only option is one or two single-family homes that must be built according to the Building Energy Act. Tiny houses or mobile homes must and can be moved. For that, you do not need a building permit, but you will certainly need some kind of permit for use for your registered address.

1. Is living in this type of house generally allowed?

There is no such thing as "this type of house". All houses built in Germany have the same basic requirements. Regulated mainly by building laws or whatever energy level requirements are called - currently the Building Energy Act.

2. We don’t know exactly whether the plot is even designated as building land and developed. Is it possible to submit an application as a "self-sufficient cabin" without electricity and with a small sewage treatment plant? If not, what options do we have and what would it roughly cost us?

Here the answer is basically the same as to the first question. All plots in Germany must meet certain basics to be allowed to be built on. Building land is one of them. But also the development must be guaranteed - i.e. electricity, water, sewage, road. Just go to the building authority. Option, if no building land: e.g. have a project-related development plan drawn up. If any community is willing to agree to that for such a small plot at all, expect 5-8 years and a (large) part of your savings.

3. What exactly does the application procedure look like here if we start with a meadow plot and want to implement the project with it?

Ask the active architect in the family. That would go beyond the scope here. You still have more than enough time. Get back to us in the 2030s if you managed to turn it into building land.

4. Assuming we have building land. Is the project possible and what does the application procedure look like?

See previous question. The architect plans the house/houses and the building application is submitted. Whether your house plans are even feasible is determined by the development plan. P.S. Such small houses become disproportionately expensive. Basically, of course, you can save an enormous amount of money if you build them yourself. But still, they must at least meet KfW 55 energy efficiency standards. And you also need the development of the plot - so also the electricity connection.

P.S. Such small houses become disproportionately expensive. Basically, you can of course save an incredible amount of money if you build them DIY. But they still have to be at least KfW 55 houses in terms of energy efficiency. And you also need the development of the property – so also the electricity connection.

Why do small houses become disproportionately expensive? If you want to carry out the project DIY (for those who are into it and have the know-how), you can relatively cheaply get a timber frame kit, for example from Poland.

Why are small houses disproportionately expensive

Because costs decrease with larger areas. Even a small house needs heating – a house three times bigger does not need a heating system three times as expensive, because the larger heater is only 15% more expensive. The craftsman charges travel costs for both houses. The water connection costs the same price. Small quantity surcharges for the concrete for the foundation. Etc. It does not depend on the house. This applies to all products in the economy. You can of course compensate by DIY. It becomes even more attractive if you build a large house yourself. Everything is always related to the price per square meter.

You have an architect who is doing the planning. Why don’t you ask him? He knows more details than we do. With 100k 100 m2 that won’t work.