The West Town GreenStar Retrofit is a historic landmarked two-flat in Ukranian Village that was converted to an efficient, healthy, and modern single-family home, while keeping interior and exterior historic character details. Special emphasis was put on indoor air quality and indoor-outdoor connections. The design focuses on non-toxic materials, good ventilation, low energy and water use, and the biophilic health advantages of light and views of nature. The kitchen, work, and family zones have views of the sun-filled south garden, an oasis in the urban environment containing native plants and fruit trees, rain garden, vegetable garden, chicken coop, apiary, and a patio. Outdoor connection and daylighting are also optimized through the skylight on the top level which spills light down the staircase. The energy strategy began with thorough retrofit insulation and air sealing, and included high performance windows and doors, solar thermal (hot water) and solar photovoltaic (electricity production) systems which support electric vehicle (EV) charging and high-efficiency smart lighting and appliances. HVAC is supplied by a combination of radiant heat, mini-split heat pumps, and a conditioning energy recovery ventilation system (CERV).