Sunday, November 8, 2009

Vancouver should be more pro-active with green roof development...

Vancouver is a “great opportunities city”- it has enormous potential to revitalize its environmental and economic environment. Vancouver’s city policies have thus far supported numerous urban sustainability solutions such as increased urban density, mixed-use developments, buildings that preserve special green space and infrastructure for transit, cycling and walking to provide non-automobile options for living in and moving between Vancouver.

What the city needs to do is bring about green roof technology through policy tools such as market-based instruments. Why? Vancouver receives a higher than average amount of precipitation than other Canadian cities. Climate change, in particular excess rainfall, can pose numerous challenges for Vancouver in the future.

Vancouver’s urban hydrologic system will have to cope with a highly fluctuating amount of surface runoff water, which can become extremely high during periods of rainfall. Climate change has the potential to intensify rainfall patterns resulting in increased risks with flooding.

When a high percentage of the city’s residents live in these compact urban areas, flooding will cause massive displacement and be an economic nightmare. Market-based instruments such as direct financial incentives, serve as the necessary policy tools to promote this technology and make it affordable. Green roof technology will serve to help the city with stormwater management and reducing risks of floods.

Market-based instruments like direct financial incentives can help make them popular and environmentally attractive. More importantly, the utilization of market-based tools can help determine if there is sufficient demand for green roof development and the economic viability of them.

Toronto recently adopted a by-law that will govern the construction of green roofs on new development. However, before this regulatory requirement came about, the city ran a program called “Toronto’s Green Roof Incentive Pilot program”. This program offered a grant of $10/m² to eligible green roofs and proved to be popular. Vancouver should run a similar program.

As mentioned, over the past 10 years, a large percent of the metropolitan region’s new housing units were built within the existing urban area. Such density is important for the city, but there must still be a sufficient amount of permeable surfaces to capture and drain rainfall so it does not runoff and cause flooding. Thus, stormwater management must be optimal to avoid flooding of a highly dense urban core.

Green roofs can help capture rainfall and ultimately improve the urban hydrologic system. This environmental reason alone should suffice and act as an impetus to begin a green roof pilot project program as done in Toronto.

Through pilot projects, knowledge and experience is gained and the city becomes more familiarized with how green roofs operate. These steps are important for bringing about green roofs because everyone benefits through increased knowledge. These sorts of policy instruments are more effective for environmental change than by simply resorting to regulatory measures. While regulation sets a precedent for the city’s commitment to sustainability, it is too precipitous to implement right now and does not provide the developer with sufficient incentives.

As stormwater management gains more salience, policy-makers will realize the benefits of providing incentives to developers and building owners to bring about green roof technology. Also, energy prices are increasing for building heating and cooling and green roofs have proven to be efficacious at minimizing these costs.

Key message: Green roofs will help Vancouver promote healthy and sustainable communities.

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