I was unaware until recently that our beautiful city of Denver sits at #11 on the list of worst air quality in the nation! Specifically for particulate and ozone pollution, which are the most common and widespread issues in the air of large cities.
We are also the 3rd city with the highest Urban Heat Island in the country. Urban Heat Island refers to when a city absorbs and maintains heat from the sun, causing city temperatures to be an average of 5 degrees hotter in the metro area than the surrounding areas.
Last November, Denver took a step towards improving Colorado’s position on those environmental issues by voting YES to the Green Roof (or living roof) Initiative, effective January 2018.
There are multiple benefits the city hopes to get from this initiative, the main ones being:
Local Air Quality Improvement – Having vegetation at the roof level helps filter air, dust, and other particles much better than a traditional roof or venting system. Living roofs have also been linked to improving mood, performance, and accuracy within workplaces as well as providing alternative lunch spaces and recreation areas for employees at work.
Storm-water Absorption and Drainage – Denver locals are too familiar with intense, heavy rainstorms that come and flood the cities densely populated streets. Adequate storm drainage is a problem that is ever-increasing as the city continues to grow. Green roofs have been named as a the best management practice by the Urban Drainage and Flood Control District to control, retain, and release storm-water.
Lower Urban Heat Island – By adding green space on buildings, plants and vegetation would be absorbing the sun’s rays while insulating the structure below by reducing heat-flow through the roof. The National Research Council of Canada says heat-flow can be reduced by 70% to 90% in the summer and 10% to 30% in the winter. The effect of this would be cooler days as well as less energy consumption throughout every building.
Urban Agriculture – This initiative also provides new space for urban farming, which would open doors to businesses working with farmers to utilize their space. This creates great relationships for local distribution, which helps Denver work towards its goal to grow/produce 20% of food locally by 2020. Call it the cherry on top, but urban agriculture on our roofs would also promote a rich biodiversity for insects and birds! Not to mention, a green roof lasts longer 2-3 times longer than a black roof!
Starting January 1st, 2018 any new construction of a building within the city of Denver with a floor space of 25,000 square feet or more will need to include a living roof covered by vegetation and solar panels or a combination of the two.
This will have a direct effect on upcoming construction, commercial real estate transactions, and insurance policies. Installing a green roof will cost more than the typical roof upfront, but will end up helping our city environment in addition to many other benefits in the long run- energy efficiency, lower operating costs, reduced structure fire risk, and increased value for future resale are just a few examples. See more below!
(Photo sourced from www.denvergreenroof.org)