Even the best designed buildings can have problems that arise after the building has been occupied. The purpose of this study was to evaluate the performance of the NW Federal Credit Union now that it has been occupied for a couple of years and determine the effectiveness of its design. With limited time, we focused our study on the buildings exterior shading devices and their ability to shade the glazed areas.
As explained in the abstract, we had two trips to the building where we conducted a series of experiments in an attempt to determine the actual effectiveness of the shading devices. The results of the visits indicated that the exterior shading devices are not completely effective in shading the glazing throughout the year. According to our computer modeling and employee surveys, the large south facing canopy along with the other shading devices only provide sufficient shading during late spring and summer. In the winter months however, the shading devices leave the first floor and part of the second floor exposed to direct sunlight (assuming the sun is shining in Seattle). This is a good strategy for solar gain, but directly conflicts with the functions of the space, which is primarily a public space where the employees interact with the banks customers. It is for security reasons that the first floor is unable to have horizontal blinds like the other floors; thus causing visual discomfort among the employees and customers. The light meter readings taken on a partly sunny day in April show a range of 300-1200f/c in a space where the suggested light levels are between 50-75f/c. The employee surveys also pointed out that the abundance of light causes glare on the computer screens, which results in an uncomfortable workspace when the sun is out during the winter months. This particular space, labeled as "first floor interior" can be seen in video (in Method section) for a better understanding of the issues at hand.
As a solution we proposed to increase the overhang of the large south facing canopy by 20%. The results, shown by the virtual computer model, didn't alleviate all of the direct sunlight, but did make a difference in the overall exposure. The other south facing shading devices were doubled in length, and tapering vertical elements were added to the east facing sun shades to alleviate glare from the direct sunlight.
Other possible solutions that would need further investigation might include: an extended investigation into other glazing types to reduce the amount of light that is transmitted without compromising the security of the Credit Union, an additional shading device under the existing south facing canopy to better shade the first floor, or the least expensive, but not too practical option is to issue sunglasses to the employees.
Despite the effects of the low sun during the winter, the employee surveys showed the majority of the employees were quite pleased with their work spaces. The lighting throughout the rest of the building was very good, in fact almost all of the main building areas during the day needed little to no artificial lighting. The lighting strategies definitely contribute to the success of the building both on how it functions, and how efficient it is. Shown in the pictures and in video, the third floor deck and lounge areas received the most compliments as comfortably lit spaces.