The start of construction keeps getting postponed

Where does it say that?

we signed a contract with a construction company stating that construction would start in spring 2020. Originally, it was planned for early March, then mid-March, then early April, and now rather mid to late April.

Very lively participant, the OP @Michael

Hello everyone, we are a family of four. I (29 years old) work full-time and my wife (28 years old) part-time, both employed in the public sector. My net salary is currently about 2300 euros and my wife's about 1100 euros. In addition, we receive child benefits twice (children are 2 and 7). That means we have a net income of about 3800 euros. In addition to our income, we own 2 condominiums. One is currently rented out for 550 euros cold rent, with a monthly installment of 300 euros and a remaining debt after the fixed interest period (2028) of 100,000 euros. We currently live in the other apartment ourselves, which would bring in about 750 euros cold rent if rented out. The monthly bank installment here is 145 euros and the remaining debt after the fixed interest period (also 2028) is about 50,000 euros. With the apartments, it is of course the case that taxes still have to be paid on the rent and reserves have to be made for vacancy or renovation work. My question now is, what kind of monthly burden is sensible in our income situation? Is there a rule of thumb for how much should be left over or how much of the rent should be set aside for losses/renovations?