Density makes New Urbanism cheaper, study says
Total infrastructure and development costs per unit and per capita are slightly lower for New Urbanism compared to conventional suburban development (CSD), according to the Canada Mortgage and Housing Corporation. The theoretical study was completed in June of 1995. The study began with a conventionally planned, 743-acre site in Nepean, Ontario. The CSD includes typical suburban loop roads and cul-de-sacs, civic buildings and shopping centers on surrounding arterial roads. Nelessen Associates of Princeton, New Jersey, was hired to design an alternative new urbanist town.
The alternative plan includes seven neighborhood centers, a primary main street commercial district, alleys and an interconnected network of streets. The new urbanist alternative has 20 percent more recreation and park lands, 16 percent greater length of roads and 15 percent more asphalt. It also has twice as much commercial use. Streets are slightly narrower for the alternative plan. Life cycle costs over a 75-year period (presented in 1994 Canadian dollars) include roads, sidewalks, sewer, stormwater systems, water, schools, parks and municipal services. Total costs were $501 million for the conventional plan and $783 million (56 percent higher) for the new urbanist alternative.
Due to narrower lot sizes and more townhomes and apartments, the new urbanist plan features 71 percent higher density than CSD (6,857 dwelling units compared to 4,005 dwelling units). “When measured on a per unit basis,” the study points out, “the alternative plan is 8.8 percent more economical. This is based on a life-cycle cost savings of $10,977 per unit. The per unit New Urbanism savings were as follows: roads ($3,054); stormwater management ($1,499); transit ($1,330); water ($1099); policing (1,016); and sanitary sewers ($975). It should be noted that the study found that rear lanes would not add to life-cycle infrastructure costs. That is because rear lanes eliminate the need for driveways, which require about the same paved service.
The Canada Mortgage and Housing Corporation acknowledged limitations of the study (although the cost analysis was rigorous, it was not broadly scrutinized; the costs were site specific; and costs can change over time). Further research was recommended in many communities at many densities and land-use mixes. Alternative development patterns should be studied on a macro, as opposed to community, level, and social and environmental costs ought to be included. Finally, the market potential of both types of plans needs further analysis.
