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There are some inherent problems with making cities affordable. Dense construction is more expensive per unit area. So even if you could spread out the cost of

There are some inherent problems with making cities affordable. Dense construction is more expensive per unit area. So even if you could spread out the cost of expensive land among many units, a high density building will cost more per unit to build. Shrinking living spaces can only be taken so far before they hurt quality of life. So city dwellers will always pay more per unit area because of building costs. Second, traffic from density imposes costs on transportation. So movement is more difficult in a dense environment. Eventually, these costs overwhelm the networking benefits of cities, and dispersion is the result. This has already happened with industry, which requires more space than services to be profitable. We are now seeing the service economy priced out of the Bay Area, leaving only the rentier economy. Density is not a panacea.

bufordsharkley 10y ago
> So city dwellers will always pay more per unit area because of building costs. And yet many will pay, because the benefits of cities are desirable. > Second, traffic from density imposes costs on transportation. So movement is more difficult in a dense environment. There may be an absolute limit, but with well-executed transit, the density of cities can offer mobility options that less dense communities could not begin to consider. > Eventually, these costs overwhelm the networking benefits of cities, and dispersion is the result. I agree, but in my take, that's largely because cities are artificially expensive owing to the speculative value of land-- you simply can't build better transit because the cost of land rights would be gigantic. You can't afford to build denser apartment buildings because homeowners enforce restrictive zoning to protect their land values... It's exactly correct that this all benefits rentiers. But I think the right solution is better land-use policy which directly targets rent.
skewart 10y ago
Maybe, as an academic exercise you could find an upper limit on the benefits of density. In practice, however, we are so far from anything remotely resembling a natural limit on the benefits to density that we will see a lot of improvements by freeing cities to become more dense. Removing the artificial constraints on growth imposed by anti-growth nativists will do a lot to improve affordability.
- jackcosgrove 10y ago
  Sure. I found this for Canada: http://www.altusgroup.com/media/4099/costguide_2015_web.pdf http://www.altusgroup.com/media/4099/costguide_2015_web.pdf Toronto (average $/sq ft to build given range) Medium Quality Tract House (assume 1 story): 180 Medium Quality Highrise (50-80 stories, average 65 stories): 270 This comes out to $1.38 more per square foot for each additional story. Let's just assume land will be twice as expensive in the city center as at the edge of that metro. Assume the cheapest land is $200 per square foot. Assume that the house will be built on the cheaper land, and assume one dwelling per story for simplicity. As you add a story, the cost of land is halved. After adding the 65th story, it is divided 65 ways. By adding the linear curve of building cost over the inverse curve of cost of land divided by story, you get the cost per square foot per story. In fact, this is maximized for a single-story building as land costs are born by a single tenant. Cost per floor falls until construction costs overcome the falling cost of land. The minimum cost to add a story, $214.67 occurs for the 12th floor. Again, back of the napkin and very naive. A highrise will probably have less square footage per dwelling though. If we halve that the cost of land falls even faster, with building costs plus land costs bottoming out at $203.51 per square foot, for the 8th floor. Finally, I added an $8,000 per square foot premium at city center. With this, the cheapest floor costs $348.44 per square foot for the sixth floor. So as land prices become steeper from city center to periphery, it actually makes more sense to disperse. Likewise reducing dwelling size does not have as much of an effect as rising build costs.
  - wott 10y ago
    And that's just the construction cost. Then the operating costs (maintenance, fluids, security, etc.) per square foot of a highrise can easily amount to 3x the one of a lowrise.
Tiktaalik 10y ago
>Second, traffic from density imposes costs on transportation. So movement is more difficult in a dense environment. haha what? no. Suburban sprawl and car oriented transportation systems are dramatically more expensive than denser communities where you can viably walk, bike and take public transit. There are all sorts of studies on this. Consider how expensive it is to walk 15 minutes to work for example. (it's free)
- wott 10y ago
  Doing the same distance in a city, compared to the countryside or small towns, always takes longer. Driving is slower (traffic jams, traffic lights, crossings everywhere...). Public transportation is slower (think train and long/middle distance busses vs local busses and subway and tramway with their stops every few hundred meters). Cycling is slower (same as for cars + the repeated effort of restarting after every slow down or stop + damn paint and gutter plates everywhere that should be avoided or ridden with care). Heck! even walking is slower (pedestrian 'jams' slowing you down, avoiding people, traffic lights, crossings every 50 or 100 meters, cars/trucks parked on sidewalks...). Basically, what's fast and efficient is a point to point transport with 'emptyness' between the nodes. It's not being bogged down on a dense axis or area.

bufordsharkley 10y ago

> So city dwellers will always pay more per unit area because of building costs. And yet many will pay, because the benefits of cities are desirable. > Second, traffic from density imposes costs on transportation. So movement is more difficult in a dense environment. There may be an absolute limit, but with well-executed transit, the density of cities can offer mobility options that less dense communities could not begin to consider. > Eventually, these costs overwhelm the networking benefits of cities, and dispersion is the result. I agree, but in my take, that's largely because cities are artificially expensive owing to the speculative value of land-- you simply can't build better transit because the cost of land rights would be gigantic. You can't afford to build denser apartment buildings because homeowners enforce restrictive zoning to protect their land values... It's exactly correct that this all benefits rentiers. But I think the right solution is better land-use policy which directly targets rent.

skewart 10y ago

Maybe, as an academic exercise you could find an upper limit on the benefits of density. In practice, however, we are so far from anything remotely resembling a natural limit on the benefits to density that we will see a lot of improvements by freeing cities to become more dense. Removing the artificial constraints on growth imposed by anti-growth nativists will do a lot to improve affordability.

jackcosgrove 10y ago
Sure. I found this for Canada: http://www.altusgroup.com/media/4099/costguide_2015_web.pdf http://www.altusgroup.com/media/4099/costguide_2015_web.pdf Toronto (average $/sq ft to build given range) Medium Quality Tract House (assume 1 story): 180 Medium Quality Highrise (50-80 stories, average 65 stories): 270 This comes out to $1.38 more per square foot for each additional story. Let's just assume land will be twice as expensive in the city center as at the edge of that metro. Assume the cheapest land is $200 per square foot. Assume that the house will be built on the cheaper land, and assume one dwelling per story for simplicity. As you add a story, the cost of land is halved. After adding the 65th story, it is divided 65 ways. By adding the linear curve of building cost over the inverse curve of cost of land divided by story, you get the cost per square foot per story. In fact, this is maximized for a single-story building as land costs are born by a single tenant. Cost per floor falls until construction costs overcome the falling cost of land. The minimum cost to add a story, $214.67 occurs for the 12th floor. Again, back of the napkin and very naive. A highrise will probably have less square footage per dwelling though. If we halve that the cost of land falls even faster, with building costs plus land costs bottoming out at $203.51 per square foot, for the 8th floor. Finally, I added an $8,000 per square foot premium at city center. With this, the cheapest floor costs $348.44 per square foot for the sixth floor. So as land prices become steeper from city center to periphery, it actually makes more sense to disperse. Likewise reducing dwelling size does not have as much of an effect as rising build costs.
- wott 10y ago
  And that's just the construction cost. Then the operating costs (maintenance, fluids, security, etc.) per square foot of a highrise can easily amount to 3x the one of a lowrise.

Tiktaalik 10y ago

>Second, traffic from density imposes costs on transportation. So movement is more difficult in a dense environment. haha what? no. Suburban sprawl and car oriented transportation systems are dramatically more expensive than denser communities where you can viably walk, bike and take public transit. There are all sorts of studies on this. Consider how expensive it is to walk 15 minutes to work for example. (it's free)

wott 10y ago
Doing the same distance in a city, compared to the countryside or small towns, always takes longer. Driving is slower (traffic jams, traffic lights, crossings everywhere...). Public transportation is slower (think train and long/middle distance busses vs local busses and subway and tramway with their stops every few hundred meters). Cycling is slower (same as for cars + the repeated effort of restarting after every slow down or stop + damn paint and gutter plates everywhere that should be avoided or ridden with care). Heck! even walking is slower (pedestrian 'jams' slowing you down, avoiding people, traffic lights, crossings every 50 or 100 meters, cars/trucks parked on sidewalks...). Basically, what's fast and efficient is a point to point transport with 'emptyness' between the nodes. It's not being bogged down on a dense axis or area.