Housing is a need almost all humans have, and there are several distinctly Solarpunk approaches to it.
Arcologies[]
Also called a 'city in a box', the word 'arcology' is a portmanteau of 'Architecture' and 'Ecology'. Designed to be at least energy and carbon neutral, if not actively generating resources, they allow for (but do not generally *require*) a lot of advanced technical solutions that have not yet reached general acceptance, such as solar-collecting windows and carbon-fiber structure. By having residential, commercial, and industrial spaces all in the same building, most transportation issues are reduced to elevator trips.
MicroHouses[]
It should be obvious that an 80-square-feet MicroHouse takes a lot less resource to use than a 5000-square foot McMansion. Put it on wheels, and even the requirement of having land to put it on can be time-shared.