You know an innovation has hit its stride when it becomes scalable. When we first started writing about green roofs, they were typically boutique projects -- and convincing city governments and developers to invest in their large scale production seemed like a major challenge. But decision-makers have gotten the message, and green roof design has risen to the occasion. Case in point: the new Vancouver Convention Centre, a major civic project which officially opened this past weekend, boasts the largest non-industrial roof in North America.

The six-acre rooftop garden is crafted as a habitat for the 400,000 native plants and grasses growing there, as well as for birds and bugs (it houses hives for 60,000 bees).

The building, designed by Seattle-based LMN Architects, in collaboration with Vancouver firms MCM and DA, is expected to achieve LEED Gold designation and incorporates significant green building technologies. Among them: natural daylighting, seawater heating and cooling, natural ventilation, and on-site blackwater treatment and desalinization systems that will reduce potable water use by as much as 60-70 percent (compared to similar-sized convention centers).

Another admirable detail: the center was designed to link visually and literally to the existing waterfront, providing usable public space instead of just swallowing it up. It adds 130,000 square feet of new waterfront promenade, and 120,000 square feet of new public plazas that flow (via the Seaside Greenway) into Stanley Park, Vancouver's well-used waterfront gem.

The convention industry is notorious for waste and excess, and for intrusion into the surrounding urban community. With its thoughtful design, the....