Who knows prefabricated house prices from 1995?

If you are a complete layman and you like a house but don't know whether the substance is worth 100 or 300 thousand euros.

As the construction expert already says...

You can compare for yourself by looking on common portals like Immo24 or Immonet to see what is offered in your area and for how much. What is spent there per square meter?! Comparison calculators are always displayed there. If an expert estimates the house at e.g. 210,000 but it is offered for 240,000, you should see what else you get for houses in this range. If there is a gap between 180,000 and 260,000 (in our area it is like this, that there is hardly any supply here), then 240,000 is also acceptable for your location...

As my predecessors already said, old production costs are of no use to you. Then, conversely, you would have to request all invoices for any possible modernizations, extensions, etc.

If you are unsure, an appraiser; as a first step, I would simply start with ImmobilienScout and see how comparable properties in your area are being traded.

A bank will currently always use the purchase price as the market value and make an internal valuation that you as a customer won't receive anyway.