We can all imagine what the exterior grounds of a turnkey house look like. You’re still miles away from lawn-only at that point.
You shouldn’t sugarcoat it either. Many people simply lack the energy to do the exterior work after the house is built and after having done their own work like priming once, painting twice, laying floors, and possibly tiling. Even under the premise “we’ll take 2-3 years for it” because there’s no rush.
With what should a layperson apply and compact the base (25cm of mineral concrete)? Something like that costs 6k€ for 230 sqm (in my case). Where is that accounted for in the calculation? I can still accept spreading gravel and paving yourself in EL. But the rough work with excavators and such? Also, the material prices set are too low. Also, the idea of covering everything else from ongoing income has been had by thousands of other builders. Of course, we had it too, but that only applies to small stuff like lamps and so on.
I myself feel it’s better to borrow more and pay back 20k€ without prepayment penalties than to have to top up 20k€ later.
And our exterior grounds won’t be finished by move-in either, why should they? There’s still plenty to do inside the house.