Construction financing - Your experiences and tips?

The 3000€ construction costs per sqm as a calculated value refer to ALL sqm of the house within the thermal envelope

But always only for a standard house without frills

The construction costs of 3000€ per sqm as a calculated value refer to ALL sqm of the house within the thermal envelope, provided there is no basement construction or similar included.

Actually not. "One" always calculates based on the living area according to DIN 277 – that is not a significant difference, but if you are in the industry, that area is always meant.

Actually not. "One" always calculates based on the living area according to DIN 277 – that is not a significant difference, but if you are in the industry, this area is always meant.

The €3000/sqm is an estimate for the user that should not cause confusion. It is only meant to be a rough figure. If a client asks with fancy demands, I would also respond accordingly.

The 3000€/sqm is a calculation for the user, which should not cause confusion.

Yes, and since providers or architects always initially only mention the living area according to DIN, it is also better to base the guideline on this area and not to additionally look for areas that do not belong to the living area. But as I said, in the end a more or less identical price results.

The 3000€/sqm is a calculation for the user, which should not confuse. It is only roughly to be determined. So if a builder asks with extravagant wishes, I would respond accordingly.

A calculation for the user - OK, on what basis was this value calculated? It was said here living area.

The costs of 600k are not achievable through external capital. A maximum of 430k + interest must be repaid, whereby it will consist of 2 loans: Kfw & regular construction loan.

As I could read from the answers, the annuity is apparently insufficient with a loan amount of 430k and a rate of €1,600. I am not sure how much construction costs can be pushed down, except for the idea of reducing the envelope, although I do not believe the noted savings potential of 100k, I see that more in lowering the energy standard to Kfw 55. But then there is no cheaper loan.

From which annuity is it acceptable?

A calculation for the user - OK, on what basis was this value calculated? It was said living area here.

This is a benchmark from practice for a normal single-family house. I am a real estate financier and deal with construction prices daily (although more with large projects - and every builder always talks about construction costs based on living area according to DIN 277 ==> therefore my statement).

As I could read from the answers, the annuity seems to be inadequate with a loan amount of 430k and a rate of €1,600.

Inadequate is not the right term. For your income, it is too low or calculated over a term of almost 40 years. So an unreasonable constellation.

I am not sure how much construction costs can be pushed down, except for the idea of reducing the envelope, although I don’t believe in the stated saving potential of €100k; I rather see that amount by lowering the energy standard to kfw 55. But then there is no cheaper loan.

The difference between 55 and 40 is no longer financially significant. I actually find 55 no longer up to date. Larger new buildings, for example, are hardly marketable anymore with the 55 standard, since every buyer of a new building project (multi-family house and bigger) assumes 40 as the standard. It gets expensive because of the certification.
And the KfW loan is also no longer really cheap (just under 3%).

From which annuity is it acceptable?

For your income, I would calculate with 2-2.5% repayment. 2% repayment then equals a 30-year term - should be around +/- 3% as a normal bank loan. So slightly more expensive than KfW but without the QNG issues.