– EVENT REPORT –
The Urban Heat Island effect can be reduced in the very near Future, if actions are taken immediately to seek out all the available options, rather than balking at the most costly solutions.
The first significant signs of a cooler, more ecologically sound Future are now becoming a reality in Toronto Ontario, because as of January 31st 2010, all new building permits issued for buildings over 2000 sq.ft. will also require Green Roof construction in the building plans. (UPDATE: See Note at bottom for a loophole that’s been discovered by some clever property developers though!). Nevertheless, however brief the Summers may be in these Northern climes, there are still all sorts of other steps that we can take to help cool our cities and reduce the enormous emissions produced by all the cooling energy that we collectively consume during hot Summer months. In fact, it’s been estimated that we could reduce the ambient temperature of our cities by as much as 3 degrees C (5degF), just by putting a few relatively simple measures into place, and reap enormous health, energy, and ecological savings immediately!
The first an most obvious thing is to get more trees in the ground, to start replacing the grand old trees that currently shade us, but which are getting very near the end of their lifetimes. Make no mistake that especially in cities like Toronto, the mature tree cover that we enjoy (but so often take for granted) is not a permanent feature, and in some cases is getting perilously close to the end of it’s useful life. There are lots of other, more complicated methods of reducing the heat island effect in the city, if you’re curious…and willing to factor in some incurred “expenses” as the only drawback to reducing future costs as energy prices will soar, while improving our entire urban landscape for all!
We can look to old Mediteranea cities for examples of building design that might not be as applicable to Northern climates, but why not look even closer to home for signs of progress?
When it’s not busy trying daring legal end-runs around the U.S. Congress to regulate carbon dioxideas a “pollutant” emitted from the nations tailpipes… The U.S. Environmental Protection Agency (EPA) can also be seen as a fount of useful environmental knowledge, which can help us build a better future, one project at a time. Here are some of the alternate plans
- Reduced stormwater runoff and improved water quality: Permeable pavements allow stormwater to soak into the pavement and soil, reducing runoff and filtering pollutants. Both permeable and non-permeable cool pavements can also help lower the temperature of runoff, resulting in less thermal shock to aquatic life in the waterways into which stormwater drains. Although the rigors of Northern Winters and frost heave, would likely relegate this technology to parking lots, or residential roads, until formulations and construction (raod-bed) methods could be perfected.
- Lower tire noise: The open pores of permeable pavements can reduce tire noise by two to eight decibels and keep noise levels below 75 decibels, although noise reduction may decline over time.2
- Enhanced safety: Permeable roadway pavements can improve safety by reducing water spray from moving vehicles and increasing traction through better water drainage.
- Better nighttime visibility: Reflective pavements can enhance visibility at night, potentially reducing lighting requirements and saving both money and energy.
- Reduced energy use: A cool roof transfers less heat to the building below, so the building stays cooler and uses less energy for air conditioning.
- Reduced air pollution and greenhouse gas emissions: By lowering energy use, cool roofs decrease the production of associated air pollution and greenhouse gas emissions.
- Improved human health and comfort: Cool roofs can reduce air temperatures inside buildings with and without air conditioning, helping to prevent heat-related illnesses and deaths.
- Reduced energy use: Green roofs absorb heat and act as insulators for buildings, reducing energy needed to provide cooling and heating.
- Reduced air pollution and greenhouse gas emissions: By lowering air conditioning demand, green roofs can decrease the production of associated air pollution and greenhouse gas emissions. Vegetation can also remove air pollutants and greenhouse gas emissions through dry deposition and carbon sequestration and storage.
- Improved human health and comfort: Green roofs, by reducing heat transfer through the building roof, can improve indoor comfort and lower heat stress associated with heat waves.
- Enhanced stormwater management and water quality: Green roofs can reduce and slow stormwater runoff in the urban environment; they also filter pollutants from rainfall. Improving swimming and wildlife habitat, due to higher treatment standards of lowered waste water volume
- Improved quality of life: Green roofs can provide aesthetic value and habitat for many species.
- Opportunities for local food production
Are there loopholes for
It seems like some clever builder’s may have found a loophole in Toronto’s new building code, where the requirement for “Green Roof” technology, can be offset by the installation of solar panels !
Exemptions for this requirement are provisioned for areas that are set aside for renewable energy installations. Since nobody will likely be installing windmills on their roofs, we can presume that this relates to solar- electric (ie.PV) panels. There are now quite a few companies out there that are willing to pay “rent” in exchange for installing solar panels on rooftops, any savvy-developer will certainly be more willing to take a small amount of money, in exchange for a big saving in building costs. Also, since there is no clear stipulation in the by-law on how densely installed the PV panels would need to be, a clever layout of their PV array, would easily fill the by-law requirement at a minimal install cost.
Also, Solar PV wouldn’t offer the same wider ecological benefits (aside from absorption of visible spectrum, and offsetting a small amount of fossil fuel generated power in between maintenance cycles of course). However, once a lease agreement for solar panels expires, there seems to be no provision in the by-law for re-designing a rooftop to fulfill the “GreenRoof” requirements after the fact, if the panels are subsequently removed, re-configured, or become obsolete over time.
Note also, that private terraces, and residential amenity areas (to a maximum of 2m2/21sf per unit) are also exempt from this “green roof requirement, so the entire goal of this initiative can be avoided with just some clever building plans, or partnerships with PV providers who also know the ins-and-outs of the generous government subsidies and grants for renewable energy. Leave it to real-estate barons to find a way to soak up the solar gains for themselves !