Several objections have been raised to rooftop gardens, including the adverse effect of excessive wind and sun on plants, as well as the lack of a load-bearing roof or permanent gardener.
But what are the options for future buildings?
1. Everyone's talking about skyscrapers, but more typical buildings of 4-8 stories have a much higher rooftop S.A. to size ratio. They also have less direct sun and wind, at least in urban areas with other buildings nearby.
2. Rooftop gardens could be mixed use to minimize weight, since grass or white pebble walkways need much less soil and weight than trees. Support could also be added to new structures.
3. Full or partial vertical blockers could ring the roof to give areas of shade and prevent excess wind. These should be cheaper than load-bearing walls.
4. A rooftop rental unit could house a gardener whose rent is subsidized or eliminated. Or one could be paid from proceeds from plot rentals.
Criticism from Engineers welcome!