Building authorities generally tolerate a 10% exceedance. This applies to objects requiring approval. I have not yet experienced them remeasuring in our area. But each district may be different. If you build over 400 sqm on a 1000 sqm single-family house plot, you should consider the environmental impact, even if you get permission. If you have a much smaller plot, it is also not good to seal 40%. A waste area can also be on gravel or lawn. Or on bare soil. Paths do not have to be continuously paved; bark mulch or just stepping stones are sufficient.