Sea-Tac (SEA) North Satellite Modernization Project

Team

Architect

Fentress Architects, w/URS Corporation

Contractor

Hensel Phelps

Stats

PROJECT TYPE

Aviation

COMPLETION

2019

PROJECT SIZE

467,684 ft²

MKA ROLE

Structural Engineer

SeaTac, WA
Sea-Tac (SEA) North Satellite Modernization Project

This four-story expansion and seismic rehabilitation of an operational airport concourse add eight new gates and 12 updated gates, a new upper-level mezzanine, a dining and retail expansion, and a new boardroom for Alaska Airlines. The project includes a new long-span roof structure that spans 260 ft and traverses entirely over the existing North Satellite designed as an undulating “river” roof that enhances the Northwest sense of place.

Image of Sea-Tac International Airport (SEA) North Satellite Modernization Project (NSAT Renovation)

Innovative and Flexible “Seismic Hug”

When the magnitude 6.8 Nisqually earthquake rattled the Seattle area in 2001, Seattle-Tacoma International Airport assessed the seismic integrity of its buildings and decided to upgrade its 1960s-era North Satellite Terminal (NSAT), adding gates and concessions, replacing the mechanical system, and incorporating innovative seismic improvements.

MKA facilitated this project by surrounding NSAT with a perimeter moment-frame lateral system—fondly referred to as a “seismic hug” and often compared to a weightlifter’s belt—that seismically reinforced the structure without needing to strengthen the existing columns and beams, saving construction-related time and costs. The design also provided an open floor plan for future flexibility. In addition, a clear-span, curvilinear “river roof” runs longitudinally through the concourse, allowing natural light to pour into the heart of NSAT and its busy retail shops, food court, and passenger circulation areas.

MKA’s innovative structural solutions completely transformed NSAT while saving tens of millions of dollars, maintaining airport operations during construction, and reducing the airport’s carbon footprint by extending the facility’s life for decades to come.