Eighty percent of Australians live within 80 miles of the sea; 50 percent of the country’s houses sit less than 8 miles from a beach. When Sean Godsell Architects began its latest experiment with an ecofriendly, rectangular residential form, the Glenburn House, it naturally built a first prototype on the coast. The precursor to this scheme, the St. Andrews Beach House, located on a peninsula south of Melbourne, is raised up on stilts above the dunes, oriented at right angles to the sea, and acts as a telescope to the horizon, where sky and ocean meet.

In contrast to the house’s straightforward shape, a looping, picturesque arrival route from the Melba Highway (named for a 19th-century opera star from Melbourne, Dame Nellie Melba) leads you to the building through a valley to the northeast of the site. Viewed from a distance, the rust-red steel box looks huge as it breasts the slopes. The winding road, however, leads to high ground behind the house, where, down a long gully, you see the volume’s midsection opening to the southwest. Parking the car, the house has remarkably shrunk to the size of a two-car garage.

You can enter the house through the garage via a mudroom, or stride along the northeastern front to the formal entry placed midway along the box. This entrance cuts through the plan along a central axis and leads to another opening, which allows access to that long gully earlier glimpsed. Inside, the program of the residence should be simple—the living, dining, sleeping, and bathing areas are meted out within a rectangle—and yet, much as the procession to the house plays with your perception, the interior is equally surprising.