Renovation obligation in old buildings, please provide an assessment

It is always "bought as seen." But you must not conceal any defects. On the other hand, it is actually a "must" to mention all renovations. Don't you want to achieve a good price? So you have to advertise your house and report everything you have already done.

Average price of what? sqm basement? sqm plot? sqm living area? sqm garage? Renovations increase prices. Open construction sites and defects lower them. Just like the age, which is usually associated with renovations/repairs still to be carried out. By the way, average is average. There are top properties and also old clunkers. You need to know which average you are talking about.

Nevertheless, the current condition must appeal to the buyer. The layout of the rooms, stairs, window area, etc. must be right. A load-bearing wall can be removed, but if the old building has several walk-through rooms, it becomes difficult.

In this case, a missing central heating system is a very big minus, which strongly prevents good prices. It may be nice that the walls are freshly plastered, but for a new heating system, some walls will have to be reopened.

If you don’t trust yourself to achieve the best possible sale, this is a case for the real estate agent. In the preliminary discussion (without commission), he will hopefully already be able to say in which price range he would set the house.

Calculate for the house rather as ground value * plot size + 1500 €/m² * living area.

What kind of formula is that?

It depends a lot on what the suitable target group is. So ask yourself critically whether the house rather falls into the category "gem, except for your personal taste" or "a feast found for the stereotypical fearless Pole."

Averages where the top and bottom tenth have not been discarded are statistically practically useless (except for tendentious political agitation).

Whoever today "not rarely" ;-) wants to install underfloor heating will not be so ungrateful for not having to first knock out radiators and pipes—the work far exceeds the metal value after all. But in the sense of my opening remark, it usually comes down more to the hardcore craftsman target group than to the jewelry hunter target group. That means the buyer would probably even be happy if he could just roll up and reuse the insulation loosely laid on the ceiling there again ;-)

What kind of formula is that?

I wanted to ask you the same in reverse – did you simply divide the house price by the plot area?