Up On The Roof

VELUX started out as a manufacturer of skylights, setting up its factory in an old brick shed in Copenhagen in 1941. Today, the company dominates the market for roof-window systems. What's inspiring about this story is that it's due to a rare combined commitment to innovation and the common good. These principles were the impetus behind VELUX's latest venture, the Atika concept house by Javier Aja Cantalejo and Roberto Aparicio Ronda.

Both men are project designers for the ACXT division of Idom, the engineering firm that collaborated with Frank O. Gehry & Associates on Spain's Guggenheim Bilbao. And both architects fit VELUX's desired profile of "someone young with untried ideas," Aja says. Their 675-square-foot one-bedroom prefab house, now on display in Madrid, fits the bill by demonstrating how state-of-the-art VELUX products can promote energy-efficient living in Mediterranean climes.

The dream of a sophisticated, industrialized architecture began with the early modernists, of course, so it's about time that dream became reality. Mass production—with its efficiencies of cost, energy, and materials—has rendered forward-looking modular houses all the rage these days, but most of the "generation next" prefabs are designed for rural or suburban settings. Atika was conceived as something else entirely: a penthouse addition for city rooftops. To combat sprawl, Aja and Aparicio propose transforming tar beaches into urban homesteads.

To develop this revolutionary dwelling, the architects turned to the Spanish vernacular for ideas. Atika's brilliantly white facade and zigzag roof—its pitches precisely angled to modulate the effects of a subtropical sun—echo a Mediterranean village's jumbled white-limed profile. The layout is borrowed from Andalusia's courtyard houses: Separate living and sleeping wings flank a patio outfitted with a small reflecting pool, plantings, and an overhang of slanting beams. This sophisticated interplay of light, shadow, and water makes for a temperate microclimate.

To buffer the interior from heat and cold, the architects stuffed 6 inches of stone-wool insulation inside the walls and under the roof—that's a material made of volcanic rock. An expert placement of windows and skylights keeps every room inviting, regardless of season, weather, or hour. A small south-facing skylight on a slightly sloped roof, for example, brings warmth and cheer into the bathroom. Windows throughout catch cooling breezes, while pitched ceilings channel hot air up and out the skylights. Wireless technology automatically orchestrates the movement of windows, blinds, shades, and shutters as well as triggering the heating and cooling systems in accordance with the hypothetical resident's predetermined settings.

Instead of an electrical compressor, VELUX's own innovative absorption chiller ironically uses hot water to power a thermodynamic cooling cycle, which distributes conditioned air via fan coils. Solar roof panels heat as much as 70 percent of the house's water and power up to 30 percent of heating and cooling requirements. An electric boiler supplements this reserve.

Because of a lightweight construction of steel and compact structural resin laminate, Atika isn't unduly heavy for its base of galvanized steel and glass. In December, the house will be dismantled and reassembled first in Valencia and later in Barcelona before continuing to cities in Portugal and Italy—all on a mission to demonstrate just how compelling and comfortable, not to mention portable, sustainable architecture can be.

From left: The roof of VELUX's Atika concept house, installed in Madrid, supports solar panels while modulating how much sun comes through the skylights. A modular unit clad in compact structural resin laminate is lowered onto a base of galvanized-steel beams and mesh.

Clockwise from top left: The patio's ipé decking wraps a reflecting pool. Floor tile in the bedroom is ceramic. The sunroom's furniture of aluminum, plastic, and nautical leather rests on a rubber rug; the ceiling's pitch of 23 degrees modulates light and ventilation. Aluminum beams form the canopy over the patio.

Clockwise from top left: The roof profile evokes that of traditional Mediterranean villages. Compact laminate, printed with the image of high-tech racing sails, clads one wall. Chairs of aluminum and micro-perforated polyester gather at the kitchen table. A stainless-steel railing surrounds the patio.

CUSTOM PANELS (EXTERIOR): FORMICA CORPORATION. MESH (BASE): IMAR. RUG (SUNROOM), FURNITURE: GANDIA BLASCO. LAMP (KITCHEN): OTYLIGHT. FLOORING: PORCELANOSA GRUPO. WINDOWS, SKYLIGHTS, SOLAR PANELS: VELUX. SLIDING DOORS: ALUMAFEL. STRUCTURAL ENGINEER: NATE CINGENIEROS. CIVIL ENGINEER, MEP: IDOM. GENERAL CONTRACTOR: MODULTEC.