Suburban land use/density in Ottawa

[waterloowarrior]

Here`s an interesting report looking at suburban land use shares and densities in pre versus post 2000 suburban Ottawa... usually the focus is only on residential density, so it's interesting to see the different distribution of other land uses in these communities, as well as the shift in unit types


introduction by David Reevely
http://communities.canada.com/ottawacitizen/blogs/greaterottawa/archive/2011/01/21/we-re-not-building-suburbs-any-denser.aspx

We're not building suburbs any denser

By DAVID REEVELY FRI, JAN 21 2011 COMMENTS(11) GREATER OTTAWA

That's what I take from this report (PDF) (http://ottawa.ca/calendar/ottawa/citycouncil/pec/2011/01-25/13%20-%20ACS2011-ICS-PGM-0007%20DOC%201%20Residential%20Ratios%20Report.pdf), which city council's planning committee is going to take a look at next week. City planning staff went out and measured the densities of 14 suburban neighbourhoods, looking to compare the densities of those built before 2000 with those built afterward. The newer ones have been constructed during a period when the city has actively sought higher densities and mixed uses, so you'd expect to find more residences packed into smaller spaces in the newer neighbourhoods.

Is that what happened? Well ... sort of. Here's the report's language, and then my interpretation:

This report reviewed 14 suburban areas in Ottawa, seven built before year 2000 and seven built during or after 2000, to assess whether there is a lower ratio of residential land in newer development. The analysis shows there has been a decrease in the percentage share of net residential land to gross land area (the net to gross ratio) in newer areas. Pre-2000 areas had an average net to gross ratio of 60.7% while post-2000 areas averaged 53.0%. Although some aspects of development are inherently unique to each area chosen for study, and consequently the results would likely differ to some degree if a different sample of areas was used, it does appear that a decline in residential land has, on average, taken place in newer residential areas. The decline recorded in the sample used is attributable to a higher share of land for natural features, stormwater facilities, schools and roads in newer areas.

At the same time, both net and gross residential densities have increased in new neighbourhoods. Net density increased by 29.9% while gross density increased 13.5%. Hence the decline in the residential net to gross ratio has had no negative effect on overall greenfield housing yields. Instead more housing is being accommodated on less land, partly due to higher densities for all dwelling unit types and partly due to a shift to higher density housing forms such as townhouses.

In other words, although newer construction is generally denser, with more townhouses and smaller detached houses, we're using less space for housing. More space is being dedicated to stormwater ponds, schools and roads. So for a neighbourhood as a whole, it's a wash.

I'm not immediately sure what this means for public budgets, the protection of which is one of the major arguments for intensification. At first glance, it looks to me like bad news: the same number of people, in smaller properties, are sharing the costs of larger public amenities. (Using more land for roads seems like a particularly problematic outcome.) The stated goal was to have more people sharing more or less the same public amenities. Instead, the ratio is going in the wrong direction. The reality is probably contingent on the specific uses, though — how much is roads, how much is parks, how much is schools

staff report
http://ottawa.ca/calendar/ottawa/citycouncil/pec/2011/01-25/13%20-%20ACS2011-ICS-PGM-0007%20-%20Residential%20Development%20Ratios.htm

Link to full report
http://ottawa.ca/calendar/ottawa/citycouncil/pec/2011/01-25/13%20-%20ACS2011-ICS-PGM-0007%20DOC%201%20Residential%20Ratios%20Report.pdf

[Dr.Z]

What?

I don't know how he can conclude:
"In other words, although newer construction is generally denser, with more townhouses and smaller detached houses, we're using less space for housing. More space is being dedicated to stormwater ponds, schools and roads. So for a neighbourhood as a whole, it's a wash."

when the preceding paragraph from the report notes:
"At the same time, both net and gross residential densities have increased in new neighbourhoods. Net density increased by 29.9% while gross density increased 13.5%. Hence the decline in the residential net to gross ratio has had no negative effect on overall greenfield housing yields. Instead more housing is being accommodated on less land, partly due to higher densities for all dwelling unit types and partly due to a shift to higher density housing forms such as townhouses."

The total density is higher in the post-2000 areas than pre-2000 areas despite the decreating net-to-gross as shown in Tables 1 and 2 of the report.

[Dado]

Ya, you're right, for him to conclude that "it's a wash" is wrong. Density, whether the net or gross measure is used, has still gone up. "A wash" would have suggested little or no change on the gross measure.

More to the point, the appearance of the 'average' new neighbourhood would have changed substantially. Where before there would be relatively low density housing with other uses thrown in here and there, now housing is getting relatively tightly packed while other uses are, if anything, increasing in the amount of land taken up. It also suggests that further gains in density are going to be ever more difficult to obtain without making use of multi-unit multi-floor residential and/or lowering the share of land used or set aside for other purposes.

[Dr.Z]

It also suggests that further gains in density are going to be ever more difficult to obtain without making use of multi-unit multi-floor residential and/or lowering the share of land used or set aside for other purposes.

Agreed. Although I would suggest that today's townhousing was yesterday's 30/35ft single lots. Couple of decades ago there wasn't much appetite for the smaller single lots, which is different today. Townhouses in Ottawa has also been traditionally very strong and I would suggest far above the average for comparatively sized municipalities.

The big question is what will the baby boomers do with their singles? A lesser question is what will the boom-echo choose for their first housing?