Looking beyond the math
Many calculations used in urban planning meaningless
The ‘ floor- space ratio’ is often a key consideration in residential development, but Bob Ransford believes there are other factors more meaningful to good urban design.
When most people walk down their neighbourhood street and pass a house or commercial building, I doubt very much that they wonder what the floor- space ratio might be for that building. Nor do very many people pull out a clinometer to triangulate the precise height of the building’s highest roof line.
However, countless regulations based on arbitrary and inflexible mathematical calculations and limits are applied when we plan our neighbourhoods and cities.
The other day, I watched the chatter on Twitter as community activists debated the math concerning a proposed rezoning to permit a mix- used development at Kingsway and Broadway in Vancouver. The debate was all about how calculations were done to represent changes in the plans affecting the height of the residential tower that is part of the development and how the FSR, or the floor- space ratio, was calculated.
I jumped into the debate with a tweet or two and suggested that good urban design gets ignored while meaningless debates ensue over formulas, math and complex text- based regulations. I also suggested calculations like FSR become a hang- up for too many. If we’re really concerned about good urban design and the impacts of a proposed development on the community, the discussion shouldn’t focus on math, but on how people will perceive the new built forms when they walk down the street, when they look out their windows or when they try to catch a bus or find a parking space in the neighbourhood.
Instead of rigidly adhering to certain arbitrary measures when we plan new growth and redevelopment, perhaps we should be looking at outcomes.
How much density, in terms of people and not floor space, actually provides the customers for neighbourhood shops, coffee houses and local transit- service improvements? What scale of a building feels comfortable creating new street walls and a human- scale sense of enclosure at the street level? What floor heights should be designated in building design to allow for future adaptability as needs change and there is a demand to convert space in buildings to different uses?
What intensity of development will allow the economics to work for more efficient energy systems to heat, cool and power buildings and provide the comforts for the people who occupy them without destroying our environment? What land- use efficiencies do we need to achieve to be able to make it economic to redevelop an existing under- utilized site and help revitalize an entire neighbourhood?
These are the kinds of questions that need to be asked. Yes, certain measures are needed to answer those questions. Formulas are needed and calculations will be required. But let’s make sure we use the ones that actually measures impacts and outcomes.
The floor- space ratio is not a measure that has much relevancy in measuring impacts, but it is one of the factors most planners and politicians seem obsessed with in trying to analyze and rationalize development.
The floor- space ratio is the ratio of the total floor area of a building or buildings on a certain location to the size of the land of that location. If I built a building that had a footprint right to the edges of the property, and it was one storey high, regardless of its actual height, it would have a floor space ratio of one. If I built a building that had only one storey, but that storey had ceiling heights, say 10 feet higher than the other building, the floor space ratio would still be one. But, if I built that same building with the high ceilings and its footprint only took up half the site, the floor- space ratio would be 0.5.
The FSR measure relates to the size of the building footprint in relation to the size of the lot it is being built on. It doesn’t relate to the actual height of the one- storey building. It doesn’t relate to how many people will occupy the building, how they will use the space, how many flush toilets will send waste water down existing sewer pipes, etc. However, the FSR is the most oft- referred- to measure used to quantify density.
Density is a big hang- up with a lot of people. The “D” word is dreaded by a lot of politicians, fearing talk of it could be dangerous to their political careers. The way we measure density, and even how we calculate FSR, often becomes the subject of acrimonious debates where trust and credibility is at stake. I’m not sure I understand why, other than it has become accepted as a standard measure by default because we haven’t focused on measuring other things that really count.
Population per hectare means something. It is a much more accurate measure of density than the floorspace ratio. Population per hectare counts the number of people occupying a defined area — a hectare. People create impacts much more than buildings do. Dwellings per hectare is another measure that seems relevant when assessing development, density and change in our neighbourhoods. Counting how many homes there are in a certain area tells you a lot about how land is being used and what impacts might arise from people living there. Correlating the two measures — people per hectare and dwellings per hectare — can tell you a lot about the way people are living in an area. Are households getting bigger or smaller?
These two measures are ones worth considering when we are trying to assess the impact of growth and redevelopment. More importantly, though, we should be looking more at qualitative rather than quantitative impacts. Assessing how design will be perceived by people as they go about their daily lives is more important than trying to assess the quantities of development.