[Schroedingersat]

Even tokyo has enough rooftops to provide most of its electricity, and your apartment building can be twice as dense if you make it twostories and cover the whole lot rather than dedicating half of the block to a driveway, dedicating the first floor to parking and making it three story.

If you limit the neighbor to n stories at the boundary and n+1 at a setback of the winter noon sun angle where n is the current building then you can get your solar cake and eat it too.

Agree on the urban farming front (delicious lead). Although when done right, high mass yield, refrigerated, low calorie produce can be a net neutral or minor win there and should he considered as reasonable as any other hobby. There is also something to be said for the follow on effects of praxis, even if the immediate effects are minor.