Case study: Office building addition
One project example of daylighting implementation and challenges is the author’s own office and building expansion that began in 2007 and was completed in 2008. While this project may be considered dated, the author can comment on the effects of working in this environment for the past decade.
Before the addition, the author was in the adjacent building with no daylighting and all fluorescent lighting fixtures with sub-3,500 K color temperatures. The addition included 75 cubicles, eight private offices, four conference rooms, a café and a commons area with exterior storefront windows and exterior sun shades. The addition was approximately 17,500 square feet and achieved U.S. Green Building Council LEED Silver certification.
One of the primary lighting goals was to provide daylighting to more than 75% of interior spaces and all of the occupied work areas. Interior daylighting distribution was accomplished using a combination of exterior windows, clerestories, skylighting and an interior courtyard.
The exterior windows on the north side with the interior courtyard are nearly continuous for the length of the addition. Exterior windows on the south sides of the addition were centered on aisleways to minimize shadowing from the 5-foot, 5-inch cubicle walls. The exterior windows allow direct viewing outdoors from 17 cubicles. The private offices and conference rooms also have exterior views into the courtyard.
Skylights are distributed throughout the open office and also centered along aisleways to provide direct viewing of the skylight lens to 38 interior cubicles. A clerestory was implemented along the west wall to bring in exterior lighting that would otherwise have been blocked by the back-of-house spaces such as restrooms and janitor closets. The remaining 20 cubicles have indirect daylighting impacts as they are, at most, one cubicle adjacent from direct views. Artificial illumination is provided with suspended linear 4,100 K T5HO fluorescent luminaires with direct and indirect distribution and occupancy-controlled task lighting.
The combinations of artificial and natural lighting results in a work space with minimal to no shadowing while working at desks and surfaces. The resulting workspace is mentally and physically comfortable and team energy is kept high, a noticeable effect of daylighting exposure.