Jason here, CEO at Edenworks.<p>Roof load is a question we get a lot, and it turns out not to be a dealbreaker if you can distribute weight on the building&#x27;s columns effectively. Our next greenhouse will be ~ 110 lbs&#x2F;s.f., which is heavy but nothing a little dunnage can&#x27;t deal with. On a side note, a research team at Columbia conducted this awesome study showing there&#x27;s over 5,000 acres of rooftop space feasible for urban farming in NYC (also recommended for any ArcGIS fans): <a href="http:&#x2F;&#x2F;urbandesignlab.columbia.edu&#x2F;files&#x2F;2015&#x2F;04&#x2F;4_urban_agriculture_nyc.pdf" rel="nofollow">http:&#x2F;&#x2F;urbandesignlab.columbia.edu&#x2F;files&#x2F;2015&#x2F;04&#x2F;4_urban_agr...</a><p>Regarding grains and legumes, you&#x27;re right and I wouldn&#x27;t recommend rooftop aquaponics for it - you simply need too much land. I do believe however that urban aquaponics can play a bigger role in supporting a growing, global middle class, which is consuming more vegetables and protein and is especially sensitive to food safety in some regions.