25-30 dwellings per hectare is 3-4 ares per dwelling. That's easily big enough for single family dwellings. Hell, you can fit a 8x12m home on a 10x20m plot with

25-30 dwellings per hectare is 3-4 ares per dwelling. That's easily big enough for single family dwellings. Hell, you can fit a 8x12m home on a 10x20m plot with a 6x10m backyard and a 2m wide front garden, and you will have 40 ares left for roads, sidewalks and curbside parking. Make the houses semi-detached and the place will even look good.