Hello,
no, actually I wanted to start now because
a) experience with (owner-occupied) house construction is still fresh
b) the municipality indicates approval in the outer area
c) land and equity capital are available
But there are also arguments against it, e.g. the currently very high construction costs and poor availability of craftsmen as well as the "problem" that potential tenants with sufficient income (but without equity capital) can currently also build without any problems.
How the municipality will behave in 10 years is also unknown. Possibly there will be an additional statute for the area then, but maybe no more special permits either.
I will approach the municipality with a preliminary draft to see if the concept I have in mind is considered feasible there. The municipality would probably prefer to see a single-family house, but I think the bigger (and therefore more expensive) it is, the harder it is to rent out, and with a duplex the probability of rent default would also be 50% lower.