Our design for the expansion and gut renovation of a small 1200 square foot house in a residential neighborhood triples is size, and reworks the living arrangement. The rear addition takes advantage of southern exposure with a "greenhouse" room that provides solar heat gain in winter, shading in summer, and a vast connection to the rear yard. Architecturally, we used an approach we call "willful practicality." The new soaring ceiling ties together first and second floors in a dramatic volumetric expansion of space, while providing increased ventilation and daylighting from greenhouse to operable windows and skylights at the peak. Exterior pockets of space are created from curved forces pushing in from outside to form cedar clad porch and stoop. Sustainable design is employed throughout all materials, energy systems and insulation. Masonry exterior walls and concrete floors provide thermal mass for the interior by insulating the exterior. An ERV system facilitates increased air changes and minimizes changes to the interior air temperature. Energy and water saving features and renewable, non-toxic materal selections are important aspects of the house design. Environmental community issues are addressed with a drywell in the side yard to mitigate rain runoff into the town sewer system. The long sloping south facing roof is in anticipation of future solar panels, with the standing seam metal roof providing anchoring opportunities for the panels. The exterior walls are clad in stucco, cedar, and cement-fiber panels defining different areas of the house. Closed cell spray insulation is applied to exterior walls and roof, giving the house an "air-tight" seal against air infiltration and a high R-value. The ERV system provides the ventilation needed with this tight envelope. The interior comfort level and economizing are the beneficial results of the building methods and systems employed in the house. Photographer: Peter Kubilus