Round ECOHAUS in Oman uses compressed earth bricks for a naturally cool home

Like the rest of the countries along the Arabian Peninsula, Oman is uncomfortably hot and humid in the summer. As a result, with ECOHAUS, student designers from the German University of Technology (GUtech) wanted to maximize the length of time the home could stay cool without using energy-intensive air-conditioning.

They used a number of passive design strategies to achieve that goal, including a cylindrical form that minimizes solar gain. But we’re especially intrigued by their choice of building materials - compressed earth bricks that are very similar to those Omanis have long used in vernacular architecture.

Thanks to the unique form, which includes round walls and strategic cutouts that allow natural light to penetrate the interior without encouraging excess heat, ECOHAUS receives significantly less solar irradiance than a similarly sized cubic design would. The earth bricks have excellent thermal mass, ensuring the interior stays cool on warm days. Insulation provides another heat barrier, while optimal orientation ensures the northern walls are shaded from direct sunlight. The east and west walls are completely closed and sunshades will protect southern openings. Natural ventilation further improves perceived comfort while reducing energy demand.

A house in a house, according to GUtech’s design brief, ECOHAUS is wrapped in a double height ring that creates yet another buffer between the core and shell, allowing the team to create different temperature zones throughout and make the most efficient use energy. Cooling, meanwhile, is based on radiation instead of convection. This system uses water to cool surfaces, while an innovative air-handling system cools and dries incoming air, recovering heat, while keeping humidity at bay. There are three bedrooms, each with its own bathroom, plus there is a living room, a dining room, and a small kitchen. Aesthetically, thanks to the interplay between straight and round walls and the staircase leading to the bedrooms upstairs, this house provided one of the most aesthetically interesting experiences I’ve had inside a house. The light and lines are gentle and comforting.

What energy is required is partially provided by rooftop solar panels and hot water is heated with solar thermal panels as well. All of the home’s appliances conserve energy and water while a building management system helps to maintain the most comfortable interior environment by controlling for humidity, temperature and air change rates. GUtech used recycled materials wherever possible in order to reduce their project’s carbon footprint and an onsite constructed wetland helps to treat blackwater, which can then be recycled to irrigate the landscaping – all of which are comprised of native plants that are adapted to the local climate and therefore require minimum hydration. The team also made use of Omani materials and craftsmen wherever possible to support the local economy. The compressed earth bricks were made onsite.

Located on GUtech’s Halban campus just outside of Muscat, the house hosts various events, workshops and further research, in addition to acting as a guest house for visitors. Having a constant stream of visitors helps, according to the team, will help to translate the “passive, active and cyclical” strategies used in the design across all aspects of Omani society.