This four-story interior office renovation in historic Harvard Square challenged the design team to bring the presence of daylight throughout a virtually windowless space with limited access to the sky. Studies of various roof-mounted reflectors and lightwell configurations using scale models and a heliodon led to the use of three south-facing, polished stainless-steel reflectors and a tapered lightwell to redirect available sunlight down through the interior floor openings below. Each reflector is fixed in place to reduce cost, and is aimed to optimize available sun throughout summer, winter, or equinox. As many as five sunlight passes per day can occur in the summer months, and the dynamic nature of the sun penetrates the full height of the narrow, windowless space, providing a valuable connection to the outdoors throughout the building core.