Pattern 17: Space Programming for Daylight, Sunlight and Variability

This pattern illustrates daylight and sunlight variability across time, and integration with lighting objectives, visual comfort criteria, and occupied times. One of the greatest opportunities in daylighting design is the synthesis of patterns of use and occupancy with patterns of daylight and sunlight. Daylight and sunlight are inherently variable and this variability provides both challenges and opportunities. Within any building program it is crucial to determine for each space type the need for daylight, views, and the tolerance for direct sunlight and distributional variability relative to the times of occupancy and the visual comfort requirements. Much of this “programming” work can be done prior to the commencement of schematic design. For example, an open office area may require a tightly controlled daylight distribution with complete sun control at all occupied times, where an employee lounge may tolerate direct sunlight during certain portions of the day or year. This has deep implications for both orientation and spatial organization.

This “pattern” illustrates distribution of diffuse daylight and patterns of direct sunlight on an hourly basis on a clear day in September. These case study patterns are based on the Northeast Seattle Branch Library addition designed by the Miller Hull Partnership and built in 2005.

Spaces examined include the central Book Stacks, Reading Area and periodicals, and the Circulation Desk with its fixed workstations for library staff.

The daylight quality in each of these spaces has a dramatically different character. Each has differing daylighting and sun control criteria that arise from the specific visual task requirements of the space and the times of day that they will be used. In essence the building and its components are organized around the patterns of daylight and sunlight.