I was looking out the window of the bus on Wilshire boulevard the other day and noticed how many hotels in the area had roofotop.... I was looking out the window of the bus on Wilshire boulevard the other day and noticed how many hotels in the area had roofotop amenities such as pools and pavilions. That got me to thinking how Manhattanites are famous for sunbathing on their roofs, or turning them into outdoor dining rooms for summer parties. That in turn led my mind to the rooftop scenes in On the Waterfront, which in turn reminded me of the classic early rock song, "Up on the Roof." Now the obvious question is, Why do we waste all that acreage, especially in cities where flat roofs are the norm?

It would make buildings a little more expensive, but not much, to increase the live load rating so that you could install rooftop gardens on every flat roof, making the structures more profitable to rent and cheaper to keep cool or warm throughout the year. This would give everyone in the building a pleasant commons--especially useful to folks on the upper floors who are far from the ground. Security and technical issue are obviously not hard to solve, since hotels, as I noted, pretty commonly make rooftops available to their guests. But why stop there?

On blocks where buildings abut, such as in many European and Eastern US cities, and where buildings don't differ greatly in height, why not conjoin all the roofs to make an aerial street? Include parks and paths, tables and shade, maybe some of the common utility areas such as laundry rooms, even places for kids to play in. Tall glass fences would keep residents at least as safe from falling as they are in their own apartments and still allow all to enjoy the view. Ramps or stairs would join roofs of different heights.

There could even be kiosk-type commerce here and there. People from different buildings would be more likely to get to know each other, there would be extra escape routes in case of fire, and you wouldn't need a permit to have a block party. One building could house the block's community garden, another the play area, another a quiet pavilion for old folks, another a kitchen and tables for dinners, and so forth.

The pooling of resources, and the presence of people from a whole block's worth of buildings, would make for a sweet community, I think, especially in areas where there is no mid-block garden or court.

It's worth considering.