> Can it really be enforced?
Yes, it can be enforced.
For example, in the US. Housing associations have staff that run around in cars taking photos of literally everything. Grass too long - Fine. Bins out outside of trash date - Fine.
This happens daily. I know because I used to live at an HOA.
My point being, hire individuals with cars to keep track of houses. Have photos of non-residency and then impose heavy fine to recoup costs.