Weekend house up to 150 k€ in BB

Personally, I don't like the floor plan. Too much hallway. KFW funding is not available for declared vacation homes. If you build the house as an owner-occupied house, then there is funding. Regarding house vs. caravan. Just do the test and rent a camper and park on a field.

would probably build a single unit and both rent it out and use it themselves.

honestly: renting it out is nonsense.
Your own living unit? From Saturday to Saturday? Then you only come by to clean and get nothing out of it. Moreover: strangers in your own living unit? What more could you want ;)
Second living unit: that also costs the equivalent of two living units. Basically, you only want to spend 150000.
To me, this is a crazy idea/bar idea… take it as you want.
Ideas about the general contractor for a small living unit don’t make it any smarter either.

I suspect there is a misunderstanding between you and the building authority. No insertion obligation requires you to make your house as large as the neighbors’. Build your masonry shed according to the Energy Saving Ordinance: a HAR with all connections and an integrated guest WC with shower, plus a main room with an exclusive kitchenette about 12 sqm in size (as far as I know, no State Prison Act requires a larger single cell). Then I see no leverage to deny you the construction permit. Whether you park a bicycle or a motorhome next to your house is purely a private matter. A registered and insured motorhome is a motor vehicle, even if it is not moved between the TÜV and gas inspection appointments. Even jacking it up to prevent the tires from standing flat does not prevent this. Park your one or two motorhomes next to your house. Just don’t call the house “tiny house,” because the word alone doubles the square meter price of the general contractor and confuses the building permit clerk.

No, you first run into those that are so small they only dare to enter the market under the wings of a franchisor. The big names are often essentially mailbox general contractors, if you don’t count their legal and marketing departments. The really big GCs/BTs are only known regionally.

I referred to the fact that I am not simply allowed to place the motorhome on the still empty plot and then spend the night there. For that, you would probably need

1. a parking space on the property
2. overnight stays would not be permitted

I will talk to a local general contractor (Makron-Bau) on Monday and also look with an architect at what can be freely planned small and realized with local craftsmen.

Well, I’ll put it this way. With DIY you always save money — the question is only to what extent. In painting work, the material only accounts for a small part of the total costs, so there is obviously excessive savings potential here.

Of course, companies want to make clear to you that you don’t save much, for example, with heating, because material costs make up a significantly larger part. However, I find this only applies according to the supplier’s calculation. Because from my point of view, it is handled in such a way that the builder pays the manufacturer’s MSRP for the heating, for example. But you can get the equipment maybe 30% cheaper over the network, so there is saving potential there too. But it should be clear that the manufacturer gives you a warranty on their work, which you don’t have if you buy your stuff everywhere at the lowest possible price.

Then there is the time you need for it. You should only undertake the complete interior fitting if you have the necessary expertise and are prepared to spend many days, weeks, or months on the construction site.

I only know the top three. The holiday home milieu is beyond my salary class =D
Additionally, I could mention Haas, without knowing more about the company, just having seen that they also offer "relatively" small bungalows in modular construction:

Thanks for the tip. I agree with you regarding the expansion and the time. With two small children there is no time to do many things yourself. The question is rather whether you can commission it more cheaply yourself.

Personally, I don’t like the floor plan. Too much hallway.
There is no KfW subsidy for declared holiday homes. If you build the house for your own use, then there is a subsidy.

Regarding house vs. caravan: try the test and rent a camper and park on a field.

It probably has to be declared as a residential house anyway, so that fits. The said house also doesn’t appeal to me in relation to the price. I will have to start over.

Honestly: renting out is nonsense.
Your own residential unit? From Sat to Sat? Then you only come by to clean and get nothing out of it. Especially: strangers in your own residential unit? What more do you want ;)
Second residential unit: that also costs as much as two residential units. In principle, you only want to spend 150,000.
To me, this is a crazy idea / pub talk idea … take it as you please.
Ideas about a general contractor for a small residential unit don’t make it any smarter either.

Knowing other people live there doesn’t bother me. I think it’s a matter of personality. I know many people who handle it exactly the same way with their holiday apartments on the Baltic Sea. Even if the management is usually through an agency.
In what way is this a crazy idea for you? Do you think a small living space cannot be created for that budget? However, I have little hope that building prices will drop significantly again.

It wouldn't be mine It wouldn't be flexibly available My coffee machine doesn't get descaled No, seriously: make it clear what you want: either for yourself or for others. Those are differences. Significant ones!

I’m afraid you will keep going around in circles for a long time.
I keep reading about renting out. As someone who has actually done this, I want to tell you that it works, you can rent out holiday apartments wonderfully and also make good sales with it.
B-U-T and this is what many holiday apartment owners dream of:
The paying holiday guest rightfully has expectations regarding service and equipment. What doesn’t bother you, bothers the guest and rightly so, because they book hotel quality. If you want good sales, you must have exclusively top reviews, otherwise you will get poor occupancy AND the corresponding clientele.
The holiday guest expects a standard that they usually don’t have at home themselves, which you can achieve through special architecture, unique location, great equipment, or special services. But all that costs money, time, and nerves. You need someone who is on site, welcomes the guests, resets the changed TV channels, explains the espresso machine, places flowers before arrival, ventilates, etc...
You should first find that person and then pay them well, because your holiday apartment idea stands or falls with them.
You yourself can use a tablecloth or bedspread with a stain or hole, just like a chipped cup rim or a stain on the wall, etc. A fancy holiday apartment must not have that or else... reviews...zingggg
As I said, it works... but not just on the side as some might think, it’s a job and you provide a service! Along with that, of course, mowed lawn all the time, nice front garden, grill, garden furniture, constant investments... the guest wants to be happy!

For me, I noticed that it was indeed a strange feeling when I sometimes saw the tenants making themselves at home in my house or doing things I wouldn’t have done myself.
If you offer the service professionally, you will also get customers who pay your price. If your service is not right or you falter, the rating collapses.
Most people with this idea don’t really want to fully see this but overlook the duties. I would look at that very carefully beforehand... By the way... a so-called cheap cookie-cutter house without flair and charm will not rent very well, a fancy one will, but that then costs a different price.

The holiday guest expects a standard that they usually do not have at home themselves; you can achieve this through special architecture, unique location, great equipment, or special services. All of that, however, costs money, time, and nerves. For that, you need someone who is on-site, welcomes the guests, resets the TV channels, explains the espresso machine, puts flowers out before arrival, airs the place, etc......
You should first find that person and then pay them well, because your holiday apartment idea stands or falls with them.

Thank you very much for the experience report, valuable input. I know the "problem" from the mentioned holiday apartments on the Baltic Sea. That was also the reason why the topic of Tiny House or hybrid house like K-Maeleon keeps coming to my mind. It just stands out. The location of the property is good, 100 m away from the lake, marina, etc. It has to be well considered and ultimately balanced so that you can manage without renting and be satisfied with personal use.