Financing land and house? Taking out a mortgage? Construction costs?

But that is not planned age-appropriately. LAN in the bedroom, if you are eventually bedridden there. Then a TV wouldn’t be bad. Even if you never need a TV there until then.

And where is the surprise now? Be glad that your husband is authorized to submit templates and that he can do the site supervision.

Probably there will be more to it, as it always is. It's not like you can't afford it. Although, of course, a lot of the property is still unpaid.

Why doesn't anyone get the idea to look in here beforehand and inquire?

That is not age-appropriate planning LAN in the bedroom, when you are eventually bedridden there...

I don't want to be a pessimist. You have to get there first.

Is the insulation between the floor slab and screed not sufficient to achieve KfW55 or is it supposed to be a "Swedish slab"?

An insulated floor slab is not a Swedish slab.
With the Swedish slab, the screed is omitted and pipes including underfloor heating are embedded in the floor slab.

Maybe, if there is money left over (höhöhöhöhö) also built-in furniture

You are already calculating with manageable costs and dreaming of built-in furniture. We have built-in furniture in various rooms. Cost: 60,000 EUR. So much for that topic. Everything a bit naive..

You're already calculating with manageable costs and dreaming of built-in furniture We have built-in furniture in various rooms. Costs: 60,000 EUR. So much for the topic Everything a bit naive..

The term "manageable" is very relative, and built-in furniture ranges from DIY to custom-made by a carpenter to high-end solutions like Kettenacker custom manufacturing. Even a shelf with a floor-to-ceiling sliding door can qualify as built-in furniture. Creatively thought of, this is not necessarily a far-fetched dream, but an alternative with a good price/performance ratio.