Frank Lloyd Wright once said, “A doctor can bury his mistakes, but an architect can only advise his clients to plant vines.” It turns out that his suggestion is also a good idea for creating handsome buildings. Green facades and living walls are outpacing green roofs as the environmentally correct way to wrap a structure.

It’s easy to see why: vertical gardens reduce cooling loads in summer by shading buildings; this “blanket effect” also cuts heating loads in winter, with the green layer acting as extra insulation. As the plants grow, they trap carbon dioxide and produce oxygen, and soak up such pollutants as lead and cadmium. Green walls absorb noise; help reduce the heat island effect, keeping cities cooler; and provide a habitat or insects and spiders, which in turn feed birds and bats. And, as Wright noted, these interventions can hide a lot of ugly buildings.

While green roofs are more efficient at min­imizing stormwater runoff, vertical gardens have a big advantage over their horizontal counterparts: they are visible to the public, where a rooftop most often is not. That’s no small consideration for an architect or client invest­ing in a sustainable structure; they want people to see the work. And unlike green roofs, vertical gardens can more easily be retrofitted onto buildings without adding a significant structural load.

Green walls come in two main varieties, ac­cord­ing to Vancouver landscape architect Randy Sharp. His firm, Sharp & Diamond, designed the Vancouver Aquarium’s 50-square-metre green wall of polypropylene modules filled with wildflowers, ferns and ground covers. A leading expert on “vegetated building envelope systems,” Sharp divides these installations into green facades, where a structure fastened to the wall provides a trellis for vines and climbers planted in the ground or in containers; and the newer living walls, where a modular grid of wall pan­els – complete with live plants, a conventional soil or layered-felt growing medium, an irrigation and nutrient-delivery system, and a support structure – is attached to the building.

French architect Edouard François is at the cutting edge of the green facade revolution. Working from the belief that “buildings must be decorated,” he’s perhaps best known for his nine-storey Tower Flower in Paris, where the facade outside each apartment holds big pots of bamboo. On his Holiday Houses vacation homes, designed with architect Duncan Lewis in Jupilles in the Loire Valley, a simple setup of chain-link fencing on wooden poles has ­morphed into a plant-covered second skin, enabling the building to disappear into the landscape. His Sproutling building in Montpellier, in southern France, however, proves much more sophisticated. Its exterior is clad in a form of gabion wall composed of rock-filled wire cages traditionally used for retaining walls. Here the architect instead employed the cages as thin panels fastened to the exterior and embedded with seeds and porous, water-retaining lava rock.

The creator says this “massive rock face will eventu­ally bloom into a spectacular vertical garden.” And his latest oeuvre, the Eden Bio social housing project in Paris, contains a hundred terraced units, artists’ studios and workshops and greenhouses, all clad in a structure planted with various flowering vines, including clematis and wisteria.