A New Kind of Green Roof

For a local arts festival held in West Vancouver in August, architect Matthew Soules constructed an ideal shading device – a massive loggia with a three-dimensional canopy planted with ryegrass and white clover.

A canopy of 260 pyramidal modules covered in living foliage that hung like honeycombs along a checkerboard grid, Vermilion Sands brought a shaded sanctuary to the Harmony Arts Festival last August. The installation’s name – a nod to a collection of short stories by sci-fi writer J.G. Ballard where nature and technology seamlessly merge – hints at the innovative thinking that went into it. It also suggests greater possibilities for the green roof.

To construct the 27.4-metre-long canopy, Matthew Soules and his firm MSA Projects shaped each module from a wire frame covered with a geotextile fabric typically used to reinforce soil embankments. The boxy forms were then hydro-seeded with a mixture of wood pulp, guar gum (a biodegradable adhesive), and seeds. Half of the modules were planted with shaggy looking ryegrass, the other with a moss-like white clover.

To keep the plants hydrated during the 10-day outdoor festival, a misting system was integrated into the steel frame structure. The light spray of water also kept visitors cool as they wandered beneath it. At night, the canopy was illuminated by LEDs, producing a gauzy, dream-like atmosphere.
According to Soules, who also teaches architecture at the University of British Columbia, the plantings grew at different rates depending on their location, creating a reflection of the site’s micro-climates. The foliage grew more quickly, for instance, where it was closer to the ocean. After the festival, most of the canopy was recycled and reused.