The River House, a fossil-fuel-free structure, sits on the banks of a river, commanding sweeping views to the south. The home’s solar crescent form allows for daylight to flood the interior. The house contains five bedrooms and accommodates large family conclaves with all interior surfaces like a fine cabinet. The living spaces are framed by two-story-high glass enclosures opening to the sky. The structure is formed around the axis to the south and center of the river. In essence, the house is made of fir - it’s like a fir box with teak jewels set inside. The designer imagined a fragile web of light wood sticks for a light wood frame to support the glass for the exterior. The luminosity continues in the roof employing a German-made 11-layered transparent polycarbonate material with an extremely high thermal performance. With passive solar design in mind, the house gains much of its warmth directly from the sun with heat energy stored in the concrete slab. The cooling source is primarily conceived through natural ventilation. The radiant floors and fan coils are served by two heat pumps. Solar arrays generate electricity to help drive the heat pumps and the house’s other electric needs.