Double O Studio tops trefoil-shaped concrete house with rooftop pool

Double O Studio has designed Trefoil House in Aroeira, Portugal, as a series of overlapping concrete shapes topped by a long swimming pool.
Set on a sandy site amongst pine trees close to the Atlantic Ocean, the two-storey house has an unusual geometry that gives it its name.
The swimming pool runs along the rooftop. Photo by Marco Antunes
The ground floor is arranged around a hexagon-shaped hall, with a kitchen, living room and dining room in adjoining, tessellating hexagons. Between the rooms,