WSP USA provided mechanical-electrical-plumbing (MEP) engineering, as well as lighting and sustainability design for the seven-story commercial office building. WSP’s MEP, Built Ecology and lighting teams collaborated with architect Weber Thompson to design and engineer Watershed to meet two of the most challenging green building standards in the world: The International Living Future Institute’s Living Building Challenge (LBC) and the City of Seattle’s Living Building Pilot program.

This project set a high bar by enrolling in these programs, both rigorous certification programs that define the most advanced measure of sustainability for buildings and landscapes. For LBC, the project selected three performance areas, or “petals”, to pursue: Place, Beauty and Materials, in which lighting played an essential role.

The WSP lighting design team took on this exciting challenge to create a design to meet these rigorous sustainability goals. Our team’s project strategies included: creating a system to capture and clean stormwater runoff from adjacent bridge and rainwater for building water needs; reducing energy consumption via high efficacy LED luminaires and advanced glazing technology; and doing detailed materials research to source local, salvaged and sustainable products, all while maintaining open communication between suppliers and team members.

The consultants and design team established an integrated multidisciplinary approach early in the design process, which helped to develop and implement synergistic lighting solutions. The developed solutions allowed for a 33 percent reduction in total energy consumption (per Seattle Energy Code baseline), with an overall lighting power density of 0.47 watts/sf. Our team’s purposeful lighting design strategically highlighted the various architectural materials rendering its character and lighting alone resulted in 48 percent less energy usage than code baselines.

PHOTOS ©MEGHAN MONTGOMERY/BUILT WORK PHOTOGRAPHY

Our design goals focused on elegance through simplicity and drawing attention to some of Watershed’s cutting-edge features. Located on a sloped lakefront site, the building’s exterior lighting creates a safe pedestrian experience and visual gateway to Seattle’s iconic Troll sculpture below the adjacent Aurora Bridge beyond. Highlighted site elements include accent lighting for the waterfall cistern of captured rainwater and runoff. Within the outdoor amenity terrace, discreet mullion mounted dimmable 3000K LED asymmetric uplights softly illuminate the cedar canopies.

Working closely with the owner, design team and contractor, our lighting team vetted luminaire submittals to confirm and document that all luminaire components were free of Red List materials (prohibited chemicals such as Mercury, PCBs, PVCs, VOCs, BPA and neoprene). We were able to maintain the original design intent and performance while utilizing only healthy materials. This multidisciplinary collaboration demonstrates how thoughtful and purposeful specifications can achieve high-quality outcomes and beautiful design.

Watershed features a 20,000-gallon cistern that collects about 200,000 gallons of rainwater each year to be treated and reused for toilets and irrigation. Additionally, 88 percent of the stormwater that falls on the site is reused, with landscaped bioswales that treat runoff from the Aurora Bridge above before it flows into Lake Union.

At 28.2kBtu/sf/year, the measured energy use intensity of Watershed is better than the modeled performance and 67 percent more efficient than the AIA 2030 benchmark building. The building’s mechanical system includes a high-performance VRF heat pump system with high-efficiency heat recovery capabilities. Additionally, the south and west primary facades feature a curtain wall with an electrochromic glazing system that automatically tints to assist with thermal comfort, energy savings, and daylight potential while maintaining expansive views. To support the annual energy targets, a measurement and verification process was developed for tenants leveraging an energy management system (EMS), which provides regular energy reports from the landlord.

To learn more about this project, read this Insights article.