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

Wow, that was even cheaper than our general contractor price. I thought awarding individual trades was cheaper? Are they made of gold?

Bavaria...? Boomtown...?
A comparative offer is available, the socket was priced at 45.... (gross prices)

A socket for 18 net only exists in SH, not in Bavaria.... there they rob each other blind.
My savings approaches:
1) Kitchen: both working, Metod from Ikea is enough. 10,000 saved.
Garage: from Rekers/Zapf or similar in concrete with manually operated gate, you are young, you can manage that without a remote control.. Definitely saves 20k.
Plastic windows Drutex Danzig: another 10 saved, Drutex is cheap...
keep kfw 55: gas and solar: 10 saved
instead of controlled residential ventilation Helios fans in bathrooms, regular air window frame vents: 10 saved
fireplace is dropped: 20 saved
instead of blinds roller shutters: 10 saved
The house is not 1 cm smaller yet, no living quality has been sacrificed yet, and we have: 90 saved.

Maybe I misunderstood the calculation...

You have 135,000 EUR equity and wanted a 400,000 EUR loan, so a total of 535,000 EUR. The 100,000 EUR was a rough estimate; I based the calculation on that and thought you would end up at least at 635,000 EUR. So not 100,000 EUR on top of the current construction costs, but rather taking out about 100,000 EUR more loan...

There could still be additional costs for earthworks. I already mentioned the electrical work. Small expenses can also add up. And I don’t understand the proportionality between a high-end standard and 3-LAN sockets, no cables, and no satellite. But well, everyone is different.

Sanitary fixtures? You don’t have those included at all! Have you even picked any out? How much do they cost? Is the acquaintance doing it for free? Outdoor facilities? 20k-30k? Where are all the incidental construction costs? Construction power, permits, etc.

Wow, our general contractor price was even cheaper. I thought individual trade contracts are cheaper? Are they made of gold?

It depends on the series. We paid about €30 for a single switch - without installation.

Maybe I misunderstood the calculation...

You have 135K EUR equity and wanted a 400K EUR loan, so a total of 535K EUR.
The 100K EUR was a rough estimate; I based my calculation on that and thought you would end up at least at 635K EUR. So not 100K EUR on top of the current construction costs, but rather taking out about 100K EUR more loan...

There could still be additional costs for the earthworks.
I already mentioned the electricity. Small expenses add up. And I don’t understand the proportionality between an upscale standard and 3-LAN sockets, no cables, and no SAT. But well, everyone is different.

Sanitary fixtures? You haven’t included those yet! Have you already picked some out? How much do they cost? Is the acquaintance doing the installation for free?
Outdoor facilities? 20k-30k?
Where are all the incidental construction costs? Construction power, permits, etc.

Now I understand.
The 405K includes sanitary fixtures, which we can get through the acquaintance via wholesale; installation is for free.
We already have the permit (exemption = no costs), as well as the structural engineering approval.
Construction power and house connections are in the calculation, about 10K.
I just hope that there won’t be any major additional costs for the earthworks, since we only need to backfill and the shell contractor already included that in the offer with insulation under the slab.

I’m slowly coming to the conclusion that we will borrow 20K from relatives and about 40K more from the bank (if that is possible that easily).
And reduce some cost drivers, first and foremost the garage. It just causes a bit of bleeding because an entrance to the house was planned through it, which only works if it is oversized. But I hope for great saving potential there.
Next on the list is the controlled residential ventilation.
And then we’ll see...

Is the insulation between the floor slab and screed not sufficient to achieve KfW55, or should it be a "Schwedenplatte"?