Urban Agriculture and Retrofit Green RoofsBy: Liza Badaloo

Aerial View of Site

Closer Aerial View of Site

401 Richmond St. West: History

Previously the Macdonald Manufacturing Co.

Known worldwide for quality metal lithographs

Building was completed in 1923.

The Transformation

1994: from historic 200,000 square foot factory to affordable downtown workspace

Most work done in 18 months

Philosophical Approaches

"Old ideas can sometimes use new buildings; new ideas must use old buildings“ (Jacobs, 1961)

vibrant mix of tenants commercial, cultural

and community activities

Rooftop Garden Elements

Began in 1995“Retrofit” greenroof 6500 square ft cedar deckLarge planters, 40 ft greenhouse, shaded

pergola (with hanging baskets, trees and shrubs)

Rooftop Garden Continued….

Rooftop Garden Cont….

Rooftop Urban Agriculture Project

Implemented in 2003Planter boxes constructed from leftover

plywood from the building workshopSome plants grown from seed in the

greenhouse, some purchased from Foodshare’s rooftop garden

Organic gardening methods were used

Urban Agriculture Project Cont….

Compost tumbler was used to provide fresh compost for plantar boxes, eliminating the need to hoist new soil onto the roof

local peat moss was used to add bulk and structure to soil

Benefits: Warmth and Roof Protection

The roof garden cedar deck provides an additional air pocket over part of the 3rd floor roof, which protects the roof membrane from freeze-thaw stretching, and provides a layer of winter insulation for the suites underneath

Reduction in heating costs for the building

Benefits: Shade

The roof garden deck and plants provide summer shade which serves to cool the suites that lie directly beneath

Reduction in cooling costs for the buildingReduces the urban heat island effect for

the city, thus reducing cooling costs for the entire city

Benefits: Stormwater Retention and Air Pollution

The trees and shrubs in the roof garden work to mitigate air pollution by trapping particulates and absorbing gaseous emissions that arise from the busy streets surrounding the building: increases air quality

Plants trap and hold rainfall that prevents polluted stormwater runoff from leaving part of the building roof: reduces CSO occurrences

Benefits: Biodiversity

The plants and flowers in the roof garden are selected, in part, for their ability to attract bees, butterflies, ladybugs, birds and other insects: increases insect and bird biodiversity

Benefits: Social

Provides tenants and visitors with a peaceful oasis in the downtown core for eating, meetings, relaxing, etc.

Trees and plants provide insulation from street noise as well as necessary shade

Benefits: Social Cont….

Residents can learn about organic gardening

Increases awareness about the potential of rooftop urban agriculture

Benefits: Food!

Peas, red cabbage, tomatoes, lettuce and many herbs are produced

Over $1500 worth of produce was produced in the first year of the project

Food used by the building café and donated to urban food security organizations

Improvement Considerations

Primary Usages/Functions: Open to the public (building code compliance,

such as rails, occupancy, etc.) Aesthetically pleasing Available for urban agriculture Increased stormwater retention Decreased urban heat island effects Increased biodiversity

Improvement Considerations Cont….

Building Structure Considerations: Roof load capacity (could put more weight on

columns, load-bearing walls, etc.) Roof membrane Drainage

Cost More costs in the first two years to establish

plants

Improvement Considerations Cont….

Time Can more time be

devoted to maintenance during the first two years?

How much time can be devoted to ongoing maintenance?

Improvement Suggestion

Replace large area of gravel by the greenhouse with extensive green roof elements such as hardy grasses, sedums, mosses, sempervivums, festucas, irises or wildflowers.

Currently….

With Suggested Improvement

HOW??

Why Extensive?

This part of the roof: Is a large area Cannot support high loads Is not used by tenants/guests

Extensive elements are: Comparatively inexpensive Comparatively low maintenance Do not require complex drainage systems

Improvement Benefits

More stormwater retention More countering of the urban heat island effect More reductions in heating/cooling building costs More air pollution reductions More roof membrane protection More attractive than gravel! Increases awareness of extensive green roof techniques

to a wide audience

***all the benefits of an extensive roof PLUS access!

Future of Green Roofs in Toronto?

February 2006: Toronto City Council approved the Green Roofs Strategy which includes: Installing green roofs on new and existing city

buildings when possible Offering financial incentives for retrofit green

roofs Generally recognizing the environmental, social

and economic potential for green roofs in Toronto

Artists’ Rendition