Headline – Just How Green Are We
Media regularly advocate being Green. That can mean reducing carbon emissions by carpooling, by walking vs. driving, being more fuel-efficient, buying locally-produced foods in season vs. food produced in, say, South America, etc.
Green Landscaping
Green also means managing how cities grow, how buildings are built, and how residential areas are developed. Zoning ordinances can focus or not focus on better livability: improve aesthetics of buildings and rights-of-way, and reduce the impact of population density. Landscaping can work for the environment -- be Green -- by providing habitat, by reducing runoff via increasing rainfall’s water-table infiltration. Green landscaping can reduce the impact of climate change factors, such as urban heating and flooding.
Can managing for Green work? How? Construction is “permitted” according to zoning ordinances. Municipalities can improve the sustainability of their jurisdiction by including in permits environmental issues, as well as things like plumbing, electrical, safety, parking, etc.
A Green Zoning Model
Seattle, Washington requires Green Factor (GFS) scoring in their Land Use Codes. GFS standards -- a minimum ratio of sustainable landscape area to total surface area -- are defined for construction types: commercial, neighborhood commercial, midrise, highrise, and lowrise family dwellings. Downtown areas and public areas are also covered. Green includes simple stuff: planting trees, preserving existing trees, and including shrubbery in designs. Using ground covers; mulching; vegetated walls; water features; and permeable pavement over deep soil improve GFS. Planting drought-tolerant plants and native species earn GFS credit. Planting edible species gets a GFS bonus.
Trying It Out
Running our home through the Green Factor Spreadsheet was interesting. Our lot is 14,833 sq. ft. and, given our native-plant/low-water-use landscape with rainwater collection system, we earned 9,191 Green points, a .62 GFS (above the highest code standard, .60). Not too shabby!
A Commercial Example
We evaluated a hypothetical commercial property - 2,175-sq.-ft. building on a 10,716-sq.-ft. lot. Drives, sidewalks, and all parking areas in concrete or asphalt covered 4,436 sq. ft. Commercial landscaping was assumed to be grass (about 4,100 sq. ft.) and four big pot plants in front. The design’s GFS was .23, well below the minimum Commercial GFS (.3). Worse -- the reason for GFS zoning -- is the property will be plain, unattractive, and hot in summertime. Most of its rainfall, 43,700 (average annual) gallons, goes into storm drains, along with hydrocarbons that drip from cars and trucks onto parking areas. That’s not Green.
Improving a Commercial Design
Using Seattle’s Green solutions recommendations, we added vegetated walls on the building’s front and one side wall, planted small shrubs across in front of the parking lot in a deep bed for bioretention of parking-area water and hydrocarbons. We added five small trees in deeply-mulched beds on the side of the driveway, and converted company parking to permeable surface over a gravel base. We added four trees in the back for a shaded employee rest/lunch area, planted with low-water-use native grass, like buffalo. Finally, we added two bioretention areas to infiltrate roof rainwater into the water table, reducing storm runoff/flooding.
This design would be Greener (earn a .47 GFS), more attractive to customers, cooler in summertime, require less mowing, retain more water as groundwater, capture more CO2, reduce potential river pollution/flooding, and be more marketable if sold. This is, of course, hypothetical. But if people design Green in -- one street, one business, one residence at a time -- it can be done at reasonable cost, and make any city, including Victoria, a better place.
Sources:
http://www.seattle.gov/DPD/cs/groups/pan/@pan/documents/web_informational/dpds021340.xlsx Green Factor Scoresheet
http://www.seattle.gov/DPD/cityplanning/completeprojectslist/greenfactor/documents/default.htm
“Clarifying Landscape Standards, including the Seattle Green Factor”, City of Seattle
Department of Planning & Development, Directors Rule 10-2011
PowerPoint presentation, Green Factor: Redux Leveraging Seattle’s Green Code to Create Urbane Spaces
Green terms --