Passive Solar House Chicago, IL In a dense urban environment, one must take advantage of every opportunity, especially in a rehab project. This three-unit building has an adjacent alley providing good access to southern sunlight. The interior of this gut-rehab was reorganized to create a "solar hall" along the south (alley) facade in both the upper owner's unit and the ground floor rental. Building mass, needed to collect the sun's energy and prevent overheating is provided in two ways: The floor is topped with 3" of concrete that also serves as the finished floor, and the wood framed walls along the hall are filled with scrap gypsum wall board salvaged during construction. Sun control is provided by a narrow landscaped balcony that shades the lower unit windows in the summer and has an adjustable, salvaged, and naturally rot-resistant cypress canopy to protect the upper unit. Virtually every structure built today has adequate windows. Yet a greater source of winter heat loss is more insidious: air movement through the building envelope via gaps at doors and windows, wall penetrations at plumbing and heating vents, and remarkably even through the brick walls in a building like this one. Sealing the building is accomplished here with spray-foam insulation within the thickened walls and ceiling. Reported utility costs were less than $40/month in the winter of 2004 versus the typical $200/month in Chicago. Other features include: • Interior clerestory windows that bring the southern light from the hall into and bedrooms and bathroom. • Heat recovery ventilation to control moisture, reduce mold formation, and improve air quality. • Roof-top deck of salvaged cypress and (future) green roof. • Salvaged marble fireplace mantle and maple floors. • Zero-VOC paints. • Radiant heat integrated with the passive solar system. Completed as Principal-in-Charge with Farr Associates