Building a house is more complicated than thought - constantly new prices!

Correct. €25 /sqm tile price is hardly sustainable anymore if it’s not the simplest tile in three color variants.

Calculating such price indications in the construction service description once with your own dimensions and quantities multiplied by current newspaper insert prices for the respective stuff gives a pretty useful preview, secondly for the “music” contained in price developments and first for the truthfulness of the catalog house offer prices (although omitting essential services in it still remains the biggest lever). There are said to be people who, due to endless Excel spreadsheet comparisons of interior plaster smoothing, faucets, and light switch covers, don’t even notice if the price applies from the top edge of the floor slab.

If you have the opportunity to purchase an existing house, I would prefer that. My husband and I are only building new because there was no suitable existing house for us in our desired area.

Even for the completely unserved prospective homeowner, a good existing property is currently even slightly more difficult to find than a building plot in most areas. In the case of the OP, who at least has already found (although as far as I understand, not yet finalized) a plot, it is relatively even exorbitantly more difficult. I would not waste a single penny thinking about such an unlikely "option."

Not every existing house needs to be completely renovated,

I see a worry-free condition in terms of substance and standard updates limited to properties aged fifteen to at most twenty years – there are reasons why I advise tapping divorce lawyers rather than real estate agents.

Furthermore, I see the advantage that you can move in promptly and take care of the rest when the situation regarding materials etc. has somewhat eased.

But don’t dream too rose-tinted: you live comparatively more comfortably in a shell house with unfinished floors than when existing coverings still need to be knocked out.

Calculating such price indications in the construction service description by multiplying them once with your own dimensions and quantities and the current newspaper insert prices for the respective stuff gives a quite usable foretaste, secondly for the music that is embedded in price developments and firstly for the truthfulness of the offer prices from catalog houses (although omitting essential services still remains the biggest leverage). It is said there are people who, due to endless Excel spreadsheet comparisons of interior plaster smoothing, faucets, and light switch covers, do not even notice when the price applies from the top edge of the floor slab.

Actually, we are not building a prefabricated house, but have bought a house-apartment (like a townhouse) from a developer. They do not build off-the-shelf houses, but only individual projects, such as, for example, the conversion of a barn in our case. Of course, we have a say in the interior design including floors and sanitary fittings and can choose for ourselves what we want. The price only includes a certain specification. So for us, only those costs came on top that we absolutely wanted ourselves (river pebble mosaic tiles in the shower and such unnecessary frills).

To sum it up: you get a functioning house in a basic standard. Nothing super modern, nothing special. But it works. If that is perfectly fine for you, then everything is great. Depending on expectations, it can be unsatisfactory.

To expand the summary: there are definitely additional costs that have nothing to do with the standard. I already mentioned the earthworks, on-site painting services, and necessary portable toilets/containers etc. P.s. I haven’t read the construction specification, but I know it from experience.

To sum it up: you get a functioning house in a basic standard. Nothing super modern, nothing special. But it works.

It doesn't work because, for example, the utility provider insists on a multi-utility connection, realistically max 2k extra cost, with the general contractor? 5? Drainage up to 0.5m outside the building.... and then the water flows by itself into the public sewer (drainage with transfer shafts realistically from 5k - 20k depending on the property and existing depth)

A reputable company does not use time or price arguments to obtain a signature – this is also the opinion I hold in the current situation.

I would not build with companies that try to pressure me, if possible. They will constantly pressure you during the construction process as well.

It is called an offer binding period and is completely normal. Especially for trades, it is absolutely understandable. In today’s time with the price developments, it is also completely normal and understandable. What do you expect? To receive an offer today whose price the house building company can still guarantee even if the contract is awarded in 4 months? If I heard something like that, I would become rather skeptical. Then the company has calculated so generously that the price increases of the next months are definitely included. Do you have to let yourself be pressured by this and sign hastily? No... Will the price get more expensive if you wait longer? Pretty sure. At least with Town & Country there used to always be a fixed date once a year when prices were increased until a few years ago. But last year they did it several times as far as I noticed.