Garden Design Online

I'm a little late this year with coverage of the annual awards of excellence by Green Roofs for Healthy Cities, but their conference was held late last year, and it more or less got buried in the holiday madness. So here goes:

Extensive Residential Award

From even a short distance away, you'd be hard pressed to know that a sizeable family compound lies underneath this lovely hillside landscape.  Designed by McGlashan Architecture of Berkeley, CA, there are two separate residences sculpted into the hillside under one extensive green roof housing three generations.  Extensive green roofs are planted in shallow soil with low-lying plants, usually no more than six inches high, that provide maximum water retention and ground cover and resistance to erosion.  According to Scott McGlashan, president of the firm, "it just felt right to compensate for disturbing the site with a living roof. Birds, bees and butterflies are regular visitors."  McGlashen added that in just two years, the roof was "a thriving ecosystem."

The judges noted that the project was "beautifully integrated into environment and landscape" and they cited in particular its success in restoring the natural ecology.

Intensive Residential Award

I have to admit I love the urban life, and if I lived in Portland, OR, I'd do my best to have a place in the ASA Flats and Lofts, designed by GGLO of Seattle.  Atop the building's retail and parking facilities, there's a five thousand-plus square foot green roof on the 4th level that includes a community vegetable garden, a sitting terrace, and expansive open space.  There's no irrigation, but there are a number of recycled whiskey barrels used for collecting rainwater.

This is an intensive green roof, ie, one that can support a more natural landscape with trees and shrubs as well as sitting areas, terraces and the like. On the 16th level, there's a sunset terrace with a common recreation area, a sitting lounge and fire pit.

GGLO Associate Marieke Lacasse said the design is "programmed for gathering and human interaction — to instill a sense of community in a very urban location." 

Intensive Institutional

I first saw this green roof back in 2006, right after it was installed.  What a difference from several years ago!  It sits stop the headquarters of ASLA in downtown Washington DC, about six or seven floors or so above street level.

Designed by Michael Van Valkenburgh Associates,  it features two planted and elevated "waves" separated by a spacious patio area. I particularly like the paths made of aluminum grating elevated three inches above the soil surface.  As people walk over them, the plants are "pruned" naturally as they grow up through the grating. Make sure to visit if you're in the DC area, and if not, there's more on the green roof here.

(photos: Green Roofs for Healthy Cities and (top) McGlashan Architecture; (middle) GGLO; and (bottom) ASLA and Conservation Design Forum)