For a more sustainable future, we need to embrace living in smaller spaces. This means not letting our houses be our primary space for every activity in our lives
Smaller, well insulated, medium density housing. Alas nothing like the current dystopian sprawl of Australian cities.
For sharing normally, i.e. students. When i had a 2 bed 1 bath apartment the dropped space just disappeared from the floor space. Drop that on 10 apartments and the developer now sells 11 apartments on that floor.