Selling a house with unauthorized extensions – What to do?

A house is generally legally tradable even with unauthorized extensions; of course, the buyer must not be deceived about this circumstance, but the legal violation lies in the unauthorized construction (which, as said, does not make the sale itself illegal). The consequence of unauthorized construction is typically a fine and an assessment of whether a demolition order should also be imposed. Consult a construction law attorney about how to legalize the situation most smoothly. Whether there are "discounts" for self-reporting, I do not know. In the past, such extensions were discovered during random checks or after denunciations; meanwhile, it has become common for building authority employees to systematically browse Google Earth out of boredom. Unauthorized buildings are not all the same; one must distinguish between permit-eligibility and merely saving the permit fee out of stinginess on one hand, and hopeless projects (violation of distance requirements, e.g. living spaces in the building setback, fire protection/escape route/insufficient room height in the attic study, etc.) on the other. This also determines the "crime-appropriate" amount of the fine or the neighbor-protection-motivated demolition. That is how I would also view it as a prospective buyer during due diligence and incorporate it into my price offer. I see no reason here for a worthless appraisal report just to file away.

If your father moves into a nursing home, you should urgently seek advice on inheritance and tax law regarding the structuring of the transfer of ownership, rather than worrying about the enforcement of fines against a nursing home resident.

Even approved extensions are usually, to put it nicely, not value-enhancing; the market will bring you back down to earth if a value is raved about in a chicken-eye-to-crystal-ball appraisal. What counts are location, location, location and, if the structure is worth preserving, also the layout of the rooms – minus the legalization and demolition costs; the fine itself hits the legal violator at the time, so this aspect hardly affects the buyer. Who actually financed the extensions back then? – by the way, I consider the claim that the mother as co-owner knew nothing to be a protective excuse.

So you think one should deceive the buyer with the help of a liking appraisal. Strange tips here in the forum.

How should we proceed to avoid subsequent fines? What consequences must we expect under these circumstances?

This is a black box question and depends not only on the extent of the unauthorized extensions but also on the attitude of the local administration staff. It may be, as described by @grundhaus, that they are quite lenient, but it can also be that someone is in charge who is conducting a campaign against this type of offender. In my former hometown, the administration evaluated aerial images (Google) to find illegal extensions. They were not squeamish, imposed fines, and ordered demolition with a short deadline. Self-reporting was "preferentially" treated – demolition was usually sufficient. It can just as well be that an official stamps an approval and laughs. I would inquire how the responsible office is and adjust my communication strategy accordingly to resolve the situation. At the latest, silence must end when selling to avoid becoming criminally liable.

We bought our house with an unapproved extension and then partially demolished it after taking possession, as we did not want to continue using the (Wintergarten).

If your father moves into a nursing home, you should urgently seek advice on inheritance and tax law regarding the transfer of ownership, rather than worrying about the enforcement of fines against a nursing home resident.

I can only agree with this here.

My assumption based on experiences in my environment (I am not a lawyer, this is not legal advice, but observations from my environment where there have already been various experiences with care cases):

1. If the house is still owned by the parents, the sales proceeds will be...
- 50% (father’s share) considered up to the retention limit.
- 50% (mother’s share) considered according to the spousal maintenance obligation. How high this is, I can only guess at the moment. Children have a very high protective barrier against parents here since the Relatives Relief Act, spouses do not have this to my recollection.

2. If the house has been transferred to relatives, the 10-year period applies; except if it is a sale at market prices.
(10-year period: Everything gifted in recent years is considered for care maintenance. Only after this is the gift secure.)

3. And here the lawyer should get involved at the latest to urgently check this: If the mother continues to live in the house and does not sell it, depending on the circumstances, it could remain untouched as exempt assets. Or not. Legal advice is needed here.

Sorry to be so pessimistic here: The situation is much more complex than the question of illegal extensions. I would not go "directly to Go" like in Monopoly, but straight to a specialized attorney.