The huge rock is about twenty metres in height and seems to balance above Spanish Water on the Caribbean island of Curaçao. Here, the architects at IMD have designed a glass house, the orientation and form of which were determined by the parameters of the site. One prerequisite: the rock and the beautiful mangroves had to remain intact. The architects set the house just behind a crevice in the rocks to shield it from the strong trade winds. They also raised the house to benefit from the views over the mangroves.

The house is in Seru Boca estate on the Caribbean island of Curaçao. It is a large estate on the east side, with a marina, the Old Quarry championship golf course, luxury hotel and villas, which have to satisfy a great many requirements as regards construction and outward form.

Most of the houses built here are substantial and invariably indifferent as regards architecture. The house underneath the rock is an exception: it is relatively small and modern in architecture, built beneath a twenty-metre, weathered, single rocky outcrop. It was created by IMD architects Anko van der Woude and Cas Aalbers.

Anko: “The clients, who were living next door, had bought this site to prevent anyone else from erecting a big house there. They wanted to build their own weekend house-cum-guest cottage on the plot. There’s a seven-metre difference in elevation on the site, the special attraction being the huge rock that seems to balance boldly on the edge of Spanish Water (which is actually an inlet of the Caribbean Sea). Local regulations forbade the blasting of the rock; moreover, the beautiful mangroves separating the land from the water had to be left intact. The rock in question, as well as those surrounding it, played a crucial role in our design plans.

The house is positioned on the west side of the rock and, as the wind generally blows from the east here, we ran the risk that no breeze could enter the edifice. That’s why we built the house just behind a crevice in the rocks – to reduce the effect of the often strong trade winds. Also, we had another important aspect to take into account: the mangroves. They had to be preserved, untouched. Since we wanted to retain the view, we built the house at a somewhat higher level.”

In fact, the brief was simple: a bedroom, bathroom and sitting room-cum-kitchen. An important requirement was a large porch for outdoor living, plus a Jacuzzi, open-air kitchen and outdoor lavatory. The architects designed the three living spaces as a logical sequence in a rectangle. Unusually, they opted for glazed walls on all sides. Not exactly the style one would expect in the tropics. However, this was a way to ensure unimpeded views. The blazing sunlight is kept out of the interior thanks to an enormous overhang of between 2 and 2.5 metres that surrounds the house. The low, early-morning sun enters the bedroom, tempered by the rocks. The impact of the afternoon and evening sun can be regulated with large vertical aluminium shutters in charcoal grey.

On the street side a wall of stone blocks provides privacy in the living areas. Flat roofs are not permitted in this region, meaning that an authorised tiled roof had to be added. The original plans to use black tiles were not approved by the planning authority. On the side of Spanish Water the architects designed a large terrace with a retractable awning from Sun Square, so the stars can be enjoyed at night. From the porch, composite decking on stilts leads round the rocks to the Jacuzzi and a point from where there is an almost panoramic view of the surroundings. The mirror pond forms a special feature; it has been built round the perpendicular rock and seems to mirror the huge piece of stone. Anko: “The large expanses of window wall led us to call this the ‘glass house’. We took it as our basis, tailoring our design to the parameters of the site as much as possible. It was nice to have good feedback from the clients, i.e. Chantal Govaerts, a fanatic yachtswoman and top-ranking golf-player who was raised on the island. She was around almost all the time, going over all the plans and ideaswith us , down to every last detail.”