Drive through rural Spain, especially the south, and you'll find lots of cave houses built into hillsides. With searing heat throughout much of the year, keeping cool is the main worry and cave houses have excellent thermal properties. Granada's House on the Cliff is a cave house like no other, and is defined by its undulating dragon scale-like zinc roof, generous glazing and energy-saving design.

House on the Cliff was commissioned by a young couple with a challenging hill plot that boasts breathtaking views of the Mediterranean. The home's striking roof comprises a double-curved concrete shell packed with insulation and clad in handmade (and hand-placed) zinc roof tiles that bring to mind a scaled dragon looking out to sea from the right angle – fitting, since dragon-starring fantasy TV show Game of Thrones is filmed nearby.

The interior is striking too. Large living and dining areas connect to a cantilevered terrace with swimming pool, while private areas including two bedrooms are located upstairs. The interior requires no internal support columns or walls, and because of the available open space, can be used as a stage and auditorium for up to 70 people. In addition, the unique furniture was made on-site using fiberglass and polyester resin.

During construction of the House on the Cliff, Madrid-based GilBartolomé Architects shunned heavy machinery and employed a labor-intensive method of constructing the two story home with large numbers of builders and laborers.

The firm says that being part-buried into the hillside enables the home to maintain a natural interior temperature of 19.5º C (67.1º F). To make full use of this, the architects installed a 40 cm (15.7-in) air cavity between the retaining walls and interior, which houses cool air. A HVAC (heating, ventilation and air-conditioning) unit monitors the temperature of the interior and determines how much of this air should be channeled inside, in addition to controlling ventilation.

Because of these steps, the home requires no further heating or cooling, year round.

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