Mercer Island, Washington, USA
Situated on a 6,500-square-foot lot on Mercer Island, Washington and designed by PUBLIC47 Architects, the East Seattle Partners (ESP) Offices embody a harmonious blend of sustainability, functionality, and aesthetic appeal.
Zoning regulations on Mercer Island limited the building to two stories and required a significant number of on-site parking stalls, leading to an automated parking system and the creation of a third-level mezzanine that provides additional workspace and a 3,500 sf landscaped roof deck.
For its architectural design, the East Seattle Partners (ESP) Offices received a 2024 American Architecture Award from the Chicago Athenaeum Museum of Architecture and Design and The European Centre for Architecture Art Design and Urban Studies.
The LEED Gold certified project strives to be timeless and convey permanence, while being environmentally responsible and forward looking.
Spatially, the project is organized around interconnected multi-story volumes bound by smaller scale spaces such as private offices, meeting rooms, break rooms, and service functions.
The objective was for the building to be both internally focused, thereby fostering collaboration, while also connecting to the surroundings and providing privacy for individual work.
Two of the primary meeting rooms employ sliding walls, which can be closed for acoustic privacy during sensitive meetings, or left open for larger company events.
Occupant health and well-being informed the design, layout, and selection of materials for the workspaces. A central staircase and an exercise room promote physical activity for occupants.
High indoor air quality is achieved though low-emitting materials and ventilation systems that provide more outside air than required by code, filtered to a high MERV standard.
All spaces feature abundant access to natural light and views to gardens and trees. A rooftop deck with a green roof provides respite and access to nature.
Building materials were carefully selected for their publicly disclosed life-cycle assessments and material ingredient declarations, enabling the team to prioritize reduced carbon impact and safety.
Regionally produced cross-laminated timber (CLT) was employed as the primary floor and roof framing material and left exposed to reveal its natural warmth and structural capabilities.
CLT is supported by a refined steel frame, allowing the building to be erected in a short time, following the time-intensive concrete site work.
All light fixtures, sprinkler heads, and penetrations were laid out and coordinated so the CLT panels could be pre-drilled at the factory, reducing issues in the field, simplifying the coordination of trades, expediting construction, and contributing to the refined aesthetic by eliminating the need for exposed conduit and sprinkler lines.
The project also benefited from collaborations between the architect, owner, contractor, and local craftspeople.
Custom light fixtures from a Seattle fabricator absorb sound, while illuminating the CLT and spaces.
The reception desk is a custom piece that integrates furniture and building, serving as both the internal identity of the company and a spatial screen.
The LEED gold, all-electric building offers an energy reduction of 47% (compared to ASHRAE 90.1-2010) through a combination of high-efficiency HVAC and heat recovery systems, a high-performance building envelope, LED lighting and daylight controls, and a roof-top solar array that generates over 18,000 kWh/ year of renewable energy, which equates to 25% of the building’s energy use.
The building was designed to achieve an EUI of 36 kBtu/sf/yr compared to an ASHRAE baseline building EUI of 54 kBtu/sf/yr.
Recent measured performance of the building resulted in a total net EUI of 28, and in combination with the energy production of the PV array, the overall EUI is 22, a significant reduction from the expected EUI of 36.
Project: East Seattle Partners (ESP) Offices
Architects: PUBLIC47 Architects LLC.
Lead Architect: Scot Carr
Landscape Architect: Karen Kiest Landscape Architects
General Contractor: Shilshole Development LLC.
Developer/Owner: East Seattle Partners LLC.
Photographers: Rafael Soldi