Assessment of construction project with own labor as well as financing

Good day,

we now finally want to take the step towards owning our own home, and it is causing us many restless nights with the knowledge of taking out such a large loan. As I have already read here, there are many good tips and experiences that I would also like to receive regarding our financing model, which might perhaps ease our worries, I hope.

Income:

He: €2100
She: €2100

no children

Planned costs for the approx. 160sqm single-family house: €420,000
In a small village

Land costs: approx. €100,000 including all additional costs

House construction 160sqm + garage: €320,000
Equity: €20,000 + €50,000 own work

Financing requirement: €350,000

where I must say right away that I am actually expecting almost €100,000 in own work but prefer to estimate it low at €50,000. Almost the entire shell construction (masonry, roofing, drywall, the majority of electricity, and a small part of plumbing and heating) is done as own work, as well as the outdoor facilities. (Realistic?)

Now we have been presented with the following offer

KFW: €100,000
+
€250,000 with 1.61% interest at 20 years fixed interest
1.46% at 15 years fixed interest

I find the interest rates relatively high despite the recognized equity of €70,000.

How do you see this? Am I just too skeptical or is something not quite optimal? I hope I have provided all important information.

I look forward to your opinion and experiences

Thank you in advance!

You should increase your own contributions so that you fall below the 80% loan-to-value limit. Then there will be a jump in interest rates. Then 0.75 to 0.85 should be achievable for 10 years. Since yesterday, KFW 55 has also become more interesting because there is an 18k grant at 0.75 for 120k.

You should increase the equity contributions so that you stay below the 80% loan-to-value limit. Then there will be an interest rate jump. Then 0.75 to 0.85 should be possible for 10 years.

That is a very good piece of information and idea! Thank you very much!

Since yesterday, KFW 55 has also become more interesting because there is an 18k subsidy at 0.75 for 120k

I am very skeptical whether solar or geothermal would be worth the additional costs before a defect occurs and new expenses arise.

I am very skeptical about whether solar or geothermal would be worth the extra costs before a defect occurs and new expenses arise.

And what does KFW 55 have to do with solar and geothermal?

Whether KfW or not. As a self-builder, you should definitely install a Panasonic Geisha LWWP yourself (2500 €).

And what does KFW 55 have to do with solar and geothermal energy?

To achieve this standard, heat recovery, solar energy, or heat pumps are usually used. Or am I completely wrong there ^^?