Feasibility of house financing 4.6k€ net 140k€ equity

Currently, it feels like there are minute-by-minute reports from banks about interest rate increases...

ING, as a pioneer, is apparently doing this every week now, last week +0.18% increase. This week +0.20%

Customers who received an offer of 1.25% for 20 years a few months ago are now paying 2.20% for 15 years at ING...
([die als Orientierung... machen immerhin 10% der Finanzierungen in Deutschland...])

Currently, it feels like there are reports from the banks about interest rate increases every minute...

This has been happening since mid/late January 2022 in a daily/weekly rhythm. Compared to the beginning of the year, we are already at 1.3 - 1.5% higher interest rates. In the same rhythm, home building companies / general contractors / craftsmen are raising prices, offers are only binding for a week anyway - after that, prices go up.

...at some point, this will affect demand, but the order books are full for this year.

Are there obligations regarding the property, for example until when xyz must be built?

yes, construction must start no later than 2 years after the purchase contract and the property must be ready to move in after 3 years.

currently, it feels like banks are reporting interest rate increases every minute...

This has been happening since mid/end of January 2022 on a daily/weekly basis. Compared to the beginning of the year, we are already at 1.3 - 1.5% higher interest rates. In the same rhythm, home construction companies / general contractors / tradesmen increase prices, offers are only valid for a week anyway - after that they go up.

Last year I would have said barely manageable. Now it won’t be possible without compromises.

yes, construction must start at the latest 2 years after the purchase contract and be ready for occupancy after 3 years.

what would be the penalty in case of breach of contract? Right of repurchase in the land register and purchase contract by the city at the sales price?

yes, start of construction at the latest 2 years after the purchase agreement and ready for occupancy after 3 years.

the question that arises is more: starting construction within 2 years after the purchase agreement, that's possible!

and the 3 years until ready for occupancy should refer to the start of construction, or to the purchase agreement? Because then the city can save the 2 years... and simply contractually stipulate that the property must be developed and ready for occupancy 3 years after purchase...

if the 3 years apply from the start of construction, then I still see it as relaxed.

I am also familiar with the 2 / 3 year rule. 2 years until the start of construction and 3 years until ready for occupancy, both counted from the purchase date of the property. The city protects itself by ensuring that construction actually takes place. This way, it can intervene after 2 years and initiate the repurchase if nothing happens. There are also nice clauses regarding the repurchase value. I hope the OP paid close attention to that. In any case, the clause about readiness for occupancy is already good. A formulation based on completion would be unfortunate; that would be legally tricky.

the question that arises rather is:
to start construction within 2 years of the purchase contract, that’s possible!

and the 3 years until readiness for occupancy should be based on the start of construction, or on the purchase contract? Because then the city could save itself the 2 years... and simply contractually regulate that the property must be built on and ready for occupancy 3 years after purchase...

if the 3 years count from the start of construction, then I still see it as manageable.