The client approached Jflemay Architecture and Design in November 2019 to design an ecological house on a forested site overlooking Lake La Salle and facing due south. The client asked for an expressed engineered timber structure clad in stone, covered with accessible green roofs and LEED certified. We proposed to divide the house into two pavilions set at different levels in order to create a diversity of viewpoints and spatial experiences. Two superposed stairs – one interior, one exterior – connect the diverse spaces from the forest floor to the panoramic roof terrace. The two pavilions are embedded into the sloping terrain in order to benefit from the constant temperature of the ground. Furthermore, the house is conditioned by an air unit exchanging heat with a geothermal well, and pumping air through ducts concealed in raised floors. Its south-facing windows, awnings and trees work in tandem to maximise solar gains in winter and minimise them in summer.