I've been reading a bit lately about high density cities. And I'm conflicted. On the one hand, density does solve a lot of problems; with more eyes on the street, crime goes down; less energy is needed for heating, driving, and entertainment. Density is also historic; not just cities, but even little town used to be highly dense. Medieval villages clustered together in little knots in an open countryside. Some people thus say that urban farming is worse then useless.
On the other hand, I think large high tech high density cities are fragile and vulnerable as the oil age winds down; they can create nature deficit disorder in people and become noisy, ugly holes. Also, people have a natural instinct for a bit of private property that they can sculpt in their likeness, and for some privacy. Some very unpleasant folks want to crowd us all in the cities so they can control us, and grab the empty countryside for themselves.
In the end, as we run out of energy we will have to use the cities we have as best we can; we can't bulldoze and rebuild everything, and it might not turn out well if we did. And WE, we permies here discussing this, CAN'T do much about building a high density city at all; that is for the big people to worry about.
So how can we rescue suburbia as the sun sets on an oil and coal driven world? Its biggest asset is land ownership and solar access. Suburbia can be seen as an opportunity to opensource innovative solutions; many small blocks of land, many of them under private control. Solar access is not cut off by tall buildings. (By suburbia, I mean the classic American dream landscape; ranch houses on quarter acre lots with paved roads, sidewalks, utilities, but not much shopping, industry, or community space, besides parks. I'm not so much talking about "pretend country" or "gentlemen's hobby farms.") It's biggest problem is how spread out and homogenous it is. Walking takes a long time to get anywhere. This helps to promote big box stores in locations only easy to reach by car.
I'd welcome ideas here.
Here follows my idea, as a springboard.
Like minded people start moving into a given suburban neighborhood; one that is still fairly livable and safe, but not a ritzy place with an HOA. They rent out rooms to help fund mortgages and increase the density; this might be difficult in some areas. The idea would be extended families splitting up houses, since this is more socially acceptable. This starts to help the density problem. If each of those big sprawling houses held 10 people instead of 4, it would make a big difference. Cars, appliances, and energy bills could thus be shared, saving energy and money. Yards would be reworked to grow food and produce energy; the suburb could not be self sufficient, but could grow all its own fruits and vegetables, and probably a lot of proteins from fish and chickens. Garages and sheds could be remodeled into workshops or small businesses, restaurants, cafes, libraries, meeting spaces. This would not be immediately possible, due to zoning, but as things wind down rules could be ignored. Tiny houses could be parked on driveways and curbsides, used as residences or food stands. All of this would promote a more vibrant, connected community. Communities could carpool more. Eventually, communal parking pads and shuttle services could be placed at the head of lesser used streets, allowing them to be broken up and repurposed. Meanwhile, arrangements with farmers outside of town could provide the remaining food for the suburb in exchange for goods and services, much as town and country have always traded. Of course, all this would be resisted mightily by the original suburbians, but as things wind down they may change their minds, or have to more out due to failed finances.
Strangely enough, I see this happening in my neighborhood. Nearly every house on my street has multiple generations living together. Many of my neighbors operate businesses from their homes. I don't know of any shared car pools, but families gather each others children from the school bus if someone isn't able to be home at that time.
Even in just the few years since I've moved here, there has been a noticeable increase in the amount of gardening going on. Some people are even raising meat animals. This doesn't just grow food. Gardeners like to talk about their gardens, and through this they grow more community ties.