Why a sloped roof revival’s taking shape

What does a house look like? To most of us, the image that comes to mind is like a Monopoly piece: a foursquare cube with a sloped roof on top. And yet among many architects, that shape has long been unfashionable. A flat-roofed modern box has been a sign of forward-thinking design for nearly a century.

But the symbolism is no longer so simple. Even as the flat-roofed house is becoming a mainstream choice, a young generation of designers has been doing creative things with sloped roofs, treating those familiar shapes in modern ways. It's the latest salvo in a century-long conversation among architects and theorists. The gabled or hipped roof – which has long been a sign of the past, either stuffy or campy – is becoming just another design tool to be tested and tried.

Omar Gandhi, a young architect in Halifax, has been employing a variety of sloped roofs on his contemporary house projects since he launched his office in 2010 – both the hipped roof, which slopes down in four directions from a high point, and the gabled roof, which is shaped like an inverted V. The results are striking: decidedly contemporary, carefully formed buildings that address, but don't bow down to, the conservative building culture of the region. Sloped roofs are everywhere, he points out, in both homes and agricultural buildings. "We think it's beautiful," he says.

Gandhi recently designed a house on Nova Scotia's South Shore for Peg and Garth Moore, a retired couple with an interest in fine art. From the front, the 1,500-square-foot building looks like a simple cedar shed with a metal roof. But look more closely: on one half, the top of the roof is lifted up to make room for a strip of windows – and on the back side the building dives down a little hill to wind up in another band of windows. If this is a Monopoly house, it's been melted and stretched dramatically out of shape.

"We wanted the building to be really simple," Gandhi explains, "very rough and shed-like on the one hand." And yet the Moores' desire for a separate studio space and the bumpy contours of the land took it in different directions.

Gandhi, and other young architects like him, is adding to a long artistic conversation. In the 1920s and 30s, one of the hallmarks of modernist architecture was a flat roof. Many European modernists of different persuasions favoured boxes; the flat roof reflected the honesty and directness of industrial architecture, and it helped reduce a building to its functional and structural essence. A gabled or sloped roof was the sign of outmoded tastes and technology.

These ideas, encoded in the so-called International Style, shaped many buildings in North America through the middle of the century. Then came the backlash: the postmodernist movement, which looked back to various building traditions and spoke directly, often whimsically, to architectural history.

Which left some highbrow provocateurs to advance the debate. The Swiss modernist architects Herzog and de Meuron have continued to use the gabled box as a playful device in their designs. They built one as a house in eastern France in the 1990s – but it is made of concrete, and suspended half a storey above ground. In 2010, they stacked up a bunch of house-like forms to create VitraHaus, the high-end furniture manufacturer's retail store, surrounded by a collection of other buildings by famous architects.

In addition to this sort of architectural inside joke, another school of architects have tried to reconcile local traditions and forms, from their own regions, with modernist ideas. Among the best in Canada have been Vancouver's Patkau Architects and Halifax's Mackay-Lyons Sweetapple (where Gandhi used to work).

The cultural politics here are fraught. The mainstream of new single-family houses are not specifically designed by architects; they are built from generic plans, shaped by vague combinations of "historic" details. For many contemporary architects and their clients, avoiding the forms of the past has been a way to define serious design.

Right now, the flat-roofed modern house is even showing up as a high-end commercial product. In cities across Canada, developers are building a growing number of houses with modernist details rather than the customary historic pastiche. "Most people who imagine a modern house imagine one with a flat roof," says Paul Johnston, a real estate agent who specializes in contemporary architecture. "It's a straight line."

And yet: Many people like the familiar. When the architects Superkul were designing a cottage in Ontario for a couple, they ran up against this tension directly. One member of the couple wanted a contemporary house, the other something "traditional." Superkul's Meg Graham explains that to solve this, "the key thing was to drill down to what that meant. You may have one understanding of what 'traditional' means and someone else might have a different one. Here, 'traditional' was more about a warmth of materials and the scale."

The result, dubbed "Stealth Cabin," is a small but complex building whose roofs slope in three directions, and which – while wrapped in cedar shakes and cedar panelling – is decidedly non-traditional in its layout, its organization and in its details. "For us the shaping of the building was more interesting than defining it as a modern building," Graham says. "Irrespective of what form the roof takes, the building is faceted and pushed and pulled in ways that make this beautiful little object."

Roof technology isn't an issue any more; as Graham points out, today's flat roofs (which are often, in reality, slightly sloped) simply do not leak as long as they're built right. On the other hand, builders (especially in rural regions) know how to build sloped roofs well. Both Graham and Gandhi cite the ease and cost savings of working with a standard building language.

But both agree that this is not the central issue; they simply don't see a reason, aesthetically or intellectually, to steer away from the sloped roof. This is sensible.

And their clients are usually happy with it. "It's something that's easily understood," Gandhi says. The Moores came to him for a contemporary house, and yet they recalled some favourite architectural memories "of an old gabled building, covered in wood," he says.

This form "exists in people's subconscious, it exists in their memories – and that's such a beautiful place to start."