Project Details
- Project Name
- North Transfer Station
- Architect
- Mahlum Architects
- Project Types
- Infrastructure
- Project Scope
- New Construction
- Shared by
- Hanley Wood
- Project Status
- Built
This article appeared in the November 2019 issue of ARCHITECT as part of our expanded coverage of the 2019 AIA COTE Top Ten Awards.
The success of this trash-processing station in a residential neighborhood shows that with a thoughtful discovery process, design can make even the most noxious building typology a boon.
Seattle’s North Transfer Station might reasonably be mistaken as a factory for electric cars or some other high-tech production facility. But the low-lying translucent glass and concrete structure actually houses a dump, right between two residential neighborhoods and less than 100 yards from the shore of Lake Union.
Much of the discovery process centered on how to make the new facility sustainable and how to make it a good neighbor. “The old station was just a dump,” Mahlum Architects design partner Anne Schopf, FAIA, says. The trash came into an open-air concrete structure and was transferred to trains to be hauled away. “We reengineered the process,” she says. It’s part of Seattle’s ambitious initiative to divert 75% of the city’s waste stream to recycling or composting by 2022.
To mitigate impact on the surrounding houses, the top of the complex was capped at 78 feet above sea level, which matches the highest point of the site at its northeast corner. This allowed the houses above the facility to retain expansive views of the lake and downtown Seattle.
Mahlum broke the complex into three distinct buildings: a two-story warehouse-like structure for waste processing, a two-story administrative building attached to the east side of the main structure, and a 10,000-square-foot recycling building bermed into the east end of the property. Trash arrives from the south side of the building via trucks that enter and exit from beneath the administration building along the east side of the main structure. The 63,246-square-foot “tipping” floor, where trash is spilled out and sorted, features 200-foot-long clear-span trusses, a translucent clerestory, and skylights that provide the workspace with 97% natural daylight. An added benefit, Schopf says, is the fact that “odor and noise can be much better [controlled] by having it contained in a warehouse.” Following sorting and processing, the trash is transferred through openings in the floor into waste haulers on the lower level.
Concrete was a given to withstand the abuse that the building needs to take, but in order to be a good neighbor, the architects deployed standard concrete formwork inserts to create a faceted pattern on the façades. That’s topped with translucent panels that surround the tipping floor—softening what could have been a large and ominous presence in the residential neighborhood.
Greenery atop both the recycling building and the administration building are part of view corridors for streets to the north. The designers increased the vegetation-supporting area of the site from 20% for the old dump to 26% now, but the biggest improvement was the consolidation of these areas as public amenities, including a new pocket park with play equipment.
The complex produces 68% fewer CO2 emissions than similar buildings. A rooftop 159.4-kilowatt photovoltaic array provides 10% of the facility’s power needs, and its size can be doubled in the future. Not only is the new North Transfer Station better integrated into the neighborhood, its capacity has doubled while mitigating noise and nuisance by placing dump activities indoors, and removing waste haulers from queuing on neighborhood streets.
“If we’re going to create sustainable, walkable, and compact communities, we need to figure out how to integrate infrastructure in a way that is livable,” Schopf says. The North Transfer Station—and its commitment to answering community needs—is an object lesson in how to do this beautifully with even the most noxious functions.
Project Attributes Architect: Mahlum Architects Owner: City of Seattle Location: Seattle Project Site: Previously developed land Building Program Type(s): Office—10,000 square feet; Other Year of Design Completion: 2014 Year of Substantial Project Completion: 2016 Gross Conditioned Floor Area: 8,499 square feet Gross Unconditioned Floor Area: 163,600 square feet Number of Stories: Two Project Climate Zone: ASHRAE 4C Annual Hours of Operation: 3,328 Site Area: 217,800 square feet Project Site Context/Setting: Urban Cost of Construction, Excluding Furnishings: $75.8 million Number of Residents, Occupants, and Visitors: 105,413
Project Credits
Project: North Transfer Station, Seattle
Client/Owner: Seattle Public Utilities
Architect: Mahlum Architects, Seattle . Mark Cork, AIA, Anne Schopf, FAIA, Pierce McVey, AIA, Luke Pulliam, AIA, Forest Payne, AIA, Rodrigo Meira, AIA, Duncan Davidson, AIA, Joseph Mayo, AIA (project team)
Architect of Record: Mahlum Architects (as a subconsultant to CDM Smith)
Prime Consultant: CDM Smith
Interior Design: Mahlum Architects
Civil Engineer: Parametrix, LPD Engineering
Structural Engineer (steel): Integrated Design Engineers
Structural Engineer (concrete): CDM Smith
Mechanical/Plumbing: The Greenbusch Group
Electrical Engineer: Triunity Engineering & Management
Landscape Architect: HBB Landscape Architecture
Acoustical: The Greenbusch Group
Cost Estimator: CDM Smith
Hardware: Adams Consulting
Hazmat: CDM Smith
Commissioning: Ecotone Commissioning Group
Geotechnical: Seattle Public Utilities
Traffic: Heffron Transportation
Solid Waste: Gordon Environmental
Size: 87,000 square feet
Cost: $108 million
Materials and Sources:
Exterior Cladding: Basalite (masonry); AEP Span (metal panels); Missoula Concrete Construction (precast concrete); Customrock, Fitzgerald (concrete formliner); Henry (BlueskinVP moisture barrier; Kelly-Moore Paints, Prosoco, PPG (exterior paints/coatings)
Roofing: Versico (elastomeric, green roof system); AEP Span (metal); Columbia Green Technologies (green roof growth media)
Windows: Kawneer (metal frame)
Glazing: PPG (glass); Kalwall (skylights); CPI Uniquad (insulated-panel or plastic glazing)
Doors: Kawneer (entrances); VT Industries (wood doors); Curries (special doors); Cookson (service doors); Rytec (overhead high-speed coiling doors)
Hardware: Best, Adams Rite, Accurate Lock & Hardware (locksets); Precision Hardware, Stanley (closers); Precision Hardware (exit devices); Trimco (pulls)
Interior Finishes: Armstrong (acoustical ceilings, suspension grid); Vision Woodworks, Contour Countertops (cabinetwork and custom woodwork); Miller Paint (paints/stains); Daltile (floor tile); Johnsonite (resilient flooring); Mannington, Patcraft (carpet)
Lighting: Focal Point, Columbia, Lithonia (interior ambient lighting); Focal Point (downlights); Lithonia, Whiteway (exterior); Dual Lite (emergency/exit lighting)
Conveyance: Schindler (elevator/escalator)
Plumbing: Elkay, American Standard (sinks, lavatories); Moen, Chicago Faucets, Kohler (faucets); Elkay (drinking fountains); American Standard (water closets, urinals); Sloan (flush valves); Zurn, BrassCraft, ProFlo, Lawler (miscellaneous fittings/valves); AO Smith (water heaters); Guardian (emergency shower/eye wash)
Energy: Artisan Electric (designer/installer, 150.0 kW DC array); Solarworld (modules); Solectria (inverters); AET (racking)
Project Description
This project is a winner in the 2019 AIA COTE Top 10 Awards:
From AIA:
One of the most community-friendly dumps in America, the North Transfer Station is in a thriving Seattle neighborhood and provides 55,500 SF of public park. The design team partnered with the neighborhood to find solutions that met everyone’s needs: a 15,000 SF green roof reduces stormwater into the city’s system; the facility generates 68% fewer CO2 emissions than the average comparable US building; translucent skylights and wall panels provide 97% daylighting for the facility; PV panels generate 150kW power; and an area for food and yard waste helps the city reach its goal to recycle 70% of its waste by 2022, and eventually reach the goal of zero-waste.
Prime Engineering Consultant: CDM Smith
Acoustical Engineer: Greenbusch Group
Civil Engineer: LPD Engineering; Parametrix
Structural Engineer: Integrated Design Engineers
General Contractor: Lydig Construction
Hardware Consultant: Adams Consulting and Estimating
Landscape Architect: HBB Landscape Architecture
Surveyor: O'Bunco Engineering Co.
Transportation Consultant: Heffron Transportation
Metrics Snapshot
Community engagement: A partnership was formed with stakeholders to share in the decision-making process including development of alternatives and identification of the preferred solution.
Walk score: 88
Estimated occupants who commute via alternative transportation (biking, walking, mass transit): 20 percent
Estimated annual carbon emissions associated with the transportation of those coming to or returning from the building: 124.9 metric tons
Percentage of the site area designed to support vegetation: 26 percent
Percentage of site area supporting vegetation before project began: 20 percent
Percentage of landscaped areas covered by native or climate appropriate plants supporting native or migratory animals: 23 percent; Most of the plantings at the site are not truly native but they are adapted to the region, drought tolerant and maintainable by city staff. Truly native planting covers 8,800 sf of the site. The planting was designed to discourage “urban wildlife” specifically rats which had been a problem with the landscaping of the previous station. The planting was not specifically designed to support native or migratory animals.
Predicted annual consumption of potable water for all uses, excluding process water:4,428,000 gal/yr
Is potable water used for irrigation? no
Predicted peak month consumption of potable water for outdoor (irrigation) purposes:process water use (for cooling, tire wash, floor wash down, misting, etc) was excluded from predicted calculations. There was no design calculation made that incorporated the typical daily consumption related to waste transfer activities.
Actual annual consumption of process water (e.g. cooling towers): 6,944,432 gal/yr
Is rainwater captured for use by the project? no
Is greywater or blackwater captured for re-use? no
Water quality for any stormwater leaving the site: 80 percent TSS Removal Efficiency
Cost per square foot: $424
Comparable cost per square foot for other, similar buildings in the region. (List source): $385/sf (escalated South Transfer Station cost, similar regional building but built during a low in the market)
Estimated annual operating cost reduction (identify baseline): The modernized facility built is completely different than what was there and was not built for operating cost reduction. If a reduction was realized it was a side benefit.
Predicted consumed energy use intensity (EUI): 33.95 kBtu/sq ft/yr
Predicted Net EUI: 30.79 kBtu/sq ft/yr
Predicted Net carbon emissions: 225 lb/sq ft/yr
Net carbon emissions refers to net purchased energy use (total energy use, less any energy generated on-site from renewable resources).
Predicted reduction from national average EUI for building type: 68 percent; The EPA's Target Finder, AIA Resources, CBECS, and other sources do not have a specific category for target EUIs of waste transfer stations, therefore this project has selected "other" as a baseline type. Seattle Public Utilities reports that the new (2012) South Transfer Station (a comparable facility) has an EUI of about 40 kbtu/sf/yr. It's important to note that predicted EUI based on LEED modeling is not necessarily an apples to apples comparison to the real world. Note that Actual and Net energy numbers do not account for the production of energy by the PV array (approximately 159.4 kW) and are based solely on utility bills.
Predicted lighting power density: 0.4 W/sq ft
Actual Consumed Energy Use Intensity (Site EUI): 39.8 kBtu/sq ft/yr
Actual net EUI: 118.5 kBtu/sq ft/yr
Actual net carbon emissions: 2,313,167 lbs
Actual reduction from national average EUI for building type: 49.5 percent
Percentage of floor area or percentage of occupant work stations with direct views of the outdoors: 96.6 percent
Percentage of floor area or percentage of occupant work stations within 30 feet of operable windows: 0 percent
Percentage of floor area or percentage of occupant work stations achieving adequate light levels without the use of artificial lighting: 97.2 percent >300 lux at 3pm March 21
Is this project a workplace? yes
How many occupants per thermal zone or thermostat: 2.23
Percentage of occupants who can control their own light levels: 66
Annual daylighting performance: 97.2 of regularly occupied area achieving at least 300 lux at least 50 percent of the annual occupied hours.
CO₂ intensity: 5492 metric tons
Estimated carbon emissions associated with building construction: 67.7 lbs/sf
LCA: Were other life-cycle assessments (LCAs) conducted? no
EPD: Were environmental product declarations (EPDs) collected? no
Percentage (by weight) of construction waste diverted from landfill: 83.24 percent
Did you calculate the percentage of materials reused from existing buildings or other local sources by weight? no
Did you calculate the percentage of materials reused from existing buildings or other local sources by volume? no
Percentage of project floor area, if any, that represents adapting existing buildings: 0 percent
Anticipated number of days the project can maintain function without utility power: 1 percent
Percentage of power needs supportable by onsite power generation: 10 percent
Carbon emissions saved through adaptive reuse vs new construction: 0
Post-occupancy evaluation summary: A Community Satisfaction Survey, consisting of questions on both the design process and the final outcome, was issued to the Wallingford and Fremont Communities in December 2018 with an 8 percent response rate. A score of 5 represents Very Satisfied, 3 represents a Neutral opinion, and 1 is Very Dissatisfied. Ten of the eighteen design criteria received a weighted average score of 4 or above, indicating satisfaction by the neighborhood community. Traffic Congestion was previously a huge problem for the neighborhood, impacting air quality and consuming fuel resources with increased wait times. It is therefore extremely gratifying to see a weighted average score of 4.30 indicating the success of strategies to eliminate idling cars backing up into the neighborhood. Notably, there were several criteria which received only Very Satisfied and Satisfied rankings: Maintaining Views, Green Factor, Reduction of Traffic Impacts and Congestion, Sustainability, CPTED Design, Fencing, and the Preservation of Existing Trees. Areas for improvement are in Odor and Noise mitigation, two of the toughest challenges for the design team. However, even here the responses were mixed with some individuals Very Satisfied while others were Very Dissatisfied. Implementation of additional mitigation strategies in these two areas are ongoing.
