Sitka Apartments

Sitka transcends all expectations of sustainable design, reaching a level of energy efficiency previously unseen at such a scale and providing a refuge to the urban dweller, bringing the beauty of the natural environment into a fast-passed setting.

Located in Seattle’s South Lake Union urban center, the 500,625 square feet, seven-story 384-unit, full-block mixed-use project has unique entrances at every street frontage, each representing an environmental characteristic of the Northwest—mountains, meadows, forests, and waterways—which act as passageways into the tree-filled courtyard for both residents and the public. The project’s rooftop community garden, vegetated roof areas, and indoor/outdoor entertainment zones were designed to connect residents to the environment. The concept of nature in the city is most clearly expressed in the property’s interior courtyard, which features a running stream, tree-covered hilltops nestled between rock walls, and an imaginative take on a treehouse.

The running stream is not the only water feature of note, the project utilizes a greywater harvesting system, a water recycling method that diverts water from showers and laundry for on-site irrigation. Ultra-low-flow toilets (0.8 gpf) are installed in all spaces, along with other low-flow fixtures. The “Swale on Yale” is a public-private project built in conjunction with Sitka, which allows the city of Seattle owned block-long biofiltration swales to collect and treat stormwater runoff from a neighboring district. And, the project achieved Salmon Safe certification for practices during construction and design elements on the project.

Throughout the design process, the project team explored various opportunities to modify the design to reduce energy consumption and improve energy performance. The team made several modifications, including increasing access to natural light, utilizing exterior elevators and walkways, and including highly visible stairs.

A key focus of Sitka’s energy-efficient design is hot water -- the largest energy use demand in new multifamily buildings. Sitka’s Wastewater Heat Recovery System utilizes water-to-water heat pumps to capture heat from outgoing wastewater to preheat the next day’s hot water supply, effectively recycling heat within the domestic water heating system.

A secondary design focus emphasizes heating and cooling. Ductless heat pumps were installed in all units facing west and south, as well as about a third of the remaining units, providing high-efficiency cooling in the summer and reducing heating electricity by a factor of three.

These energy efficiency measures, along with others, have Sitka on track to attain ambitious local 2030 targets, including significant reductions in water and energy use, $100K/year savings divided between owner and tenants, nearly 80 tons of CO2/year eliminated, and a 16 EUI rating.

Sitka seeks to bring a moment of respite, not only to its residents, but to those looking for examples of resource management and efficiency that heralds results that don’t overly burden the construction budget and pave a way for projects to achieve a path toward carbon neutrality.