COMMISSION 
AGENDA MEMORANDUM                        Item No.          9a 
BRIEFING ITEM                             Date of Meeting       March 10, 2020 
DATE:     February 14, 2020 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Jeffrey Brown, Director of Aviation Facilities and Capital Programs 
James Jennings, Director AV Properties, Airline Affairs and Air Service Development 
Wayne Grotheer, Director, Aviation Project Management 
SUBJECT:  Briefing on the C1 Building Expansion at Seattle-Tacoma International Airport 
EXECUTIVE SUMMARY 
This briefing provides an overview of the preferred concept developed for the expansion of the
C1 Building and adjacent C3 Hold room at the Seattle-Tacoma International Airport (Airport). In
June of 2018, the Commission authorized the further development of the C1 Building Expansion
project definition.
The proposed C1 Building Expansion will address current level of service deficiencies at the
Airport by constructing four additional floors on top of the existing C1 Building, as well as expand
seating in the adjacent C3 Gate Hold room, both located between Concourses C and D. This
project will also redevelop the existing concourse level footprint, which is largely blocked off from
the public today to provide additional concessions, services, and amenities to the travelling
public. Each new floor plate will be approximately 30,000 square feet, while an approximate 
5,000 square feet will be added to the existing building footprint by the construction of a new
loading dock and hold room.
Redevelopment of the existing concourse level footprint and expansion of the existing building
will provide much needed Airport Dining and Retail (ADR) options, new premium lounge spaces,
and provide additional office space for existing and new tenants. The project will also construct
a post-security Meditation Room, a Nursing Mothers Room, new restrooms, expand the deficient
C3 hold room, and create additional circulation and seating for the traveling public at the busy
and congested Concourse C and D crossroads. 
BACKGROUND 
The Airport commissioned a Project Definition Document (PDD), a more in-depth study than a
typical project notebook, which identified the boundaries of the scope for this project. The PDD 
was ultimately approved by airport leadership, after changes were incorporated from extensive
stakeholder meetings, as well as the consideration of over 200 comments following the
document review process. 

Template revised April 12, 2018.

COMMISSION AGENDA  Briefing Item No. _9a_                                Page 2 of 5 
Meeting Date: March 10, 2020 
The project team worked with Airport Operations to ensure a comprehensive Safety Risk
Assessment to assure sufficient space will be available for air carrier movement on and around
the ramp area as well as continued visual observation of the dual taxi lane between Concourse C
and the North Satellite will be maintained.
Further strategies to manage, or alleviate ramp area congestion, in the areas of Concourse C and
D, include a future Centralized Receiving Distribution Center, by way of ensuring there are only
box truck type deliveries to the load dock. Deliveries will still be able to access the building by
way of the central terminal load dock. 
The proposed C1 Building Expansion project, will provide solutions to deficient ADR, hold room,
lounge and office capacities by adding four floors to the existing C1 Building, increasing the
existing approximate 99,000 SF facility to roughly 203,000 SF, and expand the adjacent C3 Hold
room by approximately 1,500 square feet. 
The Airport currently underserves the demand of the traveling public with ADR options in
Concourses C and D. With the addition of C1's 24,000 square feet of ADR space within the next
five years, the Airport will still not meet current demand. Additionally, the existing passenger
hold room at Gate C3 is significantly undersized to serve current aircraft and would be expanded
to meet standard level-of-service criteria and avoid congestion on the adjacent concourse
walkways. 
The C1 Building expansion includes approximately 40,000 square feet of office space, 14,000 SF
of which is for TSA on the Bridge level, and another 7,000 SF of office for use by lounge operators 
The remaining 19,000 SF will be allocated to either ADR tenants, or the Port of Seattle. 
The Port of Seattle has received multiple letters of interest from tenants for potential lounge
spaces in anticipation of the C1 Building Expansion project. Specific tenants for this lounge space
are in preliminary negotiations. 
Furthermore, the expanded facility will include the ability to accommodate All Gender
Restrooms, Mediation Rooms and Nursing Mothers Suites. 
ADDITIONAL BACKGROUND 
The C1 project will be the first project that has been identified as a "Tier three project" under the
Port's new Sustainable Project Framework; and  the project team will execute design and
construction work consistent with the following Commission-approved approach: 
1. Integrate sustainability early in the capital process by establishing a team of project-
specific experts through the Sustainable Project Assessment and Review Committee
(SPARC). 
2. Select and apply the relevant Sustainable Evaluation Framework criteria to highlight
tradeoffs and benefits during development of the Sustainable Design Approach. 

Template revised September 22, 2016.

COMMISSION AGENDA  Briefing Item No. _9a_                                Page 3 of 5 
Meeting Date: March 10, 2020 
3.  Present  SPARC  recommendations/SDA  to  Commission  along  with  the  request  for
authorization for design funds. 
4. Develop a Sustainable Design Strategy that includes the selected alternatives from the
Sustainable Design Approach. Share results and recommendations of the Strategy with
Commission's Energy and Sustainability Committee at 30% design. 
5. The Sustainable Design Strategy will be included in the final construction authorization for
the project. 
6. Track progress and recognize achievements of project teams. 
The project team worked with the Aviation Environmental (AVENV) department to convene and
conduct a SPARC meeting to identify ideas and analyses for the C1 Sustainable Design Approach 
(SDA). In addition to pursuing certification for Silver level for the most current version of LEED
Building Design and Construction, the SDA requires the designer conduct the following analyses 
as the design develops for the sustainability categories relevant to the project prior to the 
completion of the 30 percent design deliverable:
Category        Analyses 
Energy/Carbon   Analyze energy use (electricity, liquid fuel, natural gas) and options for
reducing energy use by 5%, 10%, and 20% below Washington State Energy
Code. For each proposed option, analyze capital and total costs. AVENV will
calculate carbon emission and reduction estimates associated with proposed
options. 
Materials        Provide Port staff with technical specifications and amounts of concrete,
steel, and gypsum proposed for use on the project. Staff will analyze options
and provide recommendations to reduce embodied carbon for those
materials. 
Water         Analyze water use and cost and provide options to reduce water use by 10%
conservation     and 20% below Uniform Plumbing Code 2015 and Washington State
Amendments. Options include but are not limited to indoor water use,
outdoor water use, process water demand, and rainwater capture. Proposed
options must meet the Port's existing design standards. 
Transportation   Develop project-specific design options to support employees that commute
via active transportation, public transportation, or other non-drive alone
modes. Include cost estimates for all proposed options. 
Innovation       Analyze and propose any additional options that could be considered
innovative techniques. Designer must provide evidence of  past precedent
within the last three years and corresponding performance data for Port
review. 


Template revised September 22, 2016.

COMMISSION AGENDA  Briefing Item No. _9a_                                Page 4 of 5 
Meeting Date: March 10, 2020 
SCHEDULE 
Planning Phase                                            Quarter 
PDD Approved by aviation leadership                      Complete 
State Environmental Policy Act (SEPA) Determination        Q2, 2020 
Commission Briefing                                      March 10, 2020 
Commission Authorization to procure Design               Q1, 2020 
Commission Authorization to procure General Contractor/  Q2, 2020 
Construction   Manager   (GC/CM),   and   Program
Management 
Design Phase                                              Quarter 
Procure Design Services Complete                          Q3, 2020 
Procure GC/CM services complete                         Q4, 2021 
Review recommendations of sustainable design strategy  Q2, 2021 
with the E&S committee at the 30 % design submittal 
Design Complete                                        Q2, 2022 
Construction Phase 
Commission Authorization for Construction                 Q3, 2022 
Demolition begins                                         Q3, 2022 
Substantial Completion                                    Q3, 2027 

ESTIMATE 
The estimated cost for the C1 Building Expansion program is $340M. This estimated cost is based
on project definition between 1 and 15 percent complete, which makes its estimate a class 4
estimate. While the PDD defines the boundary of the scope, design has not begun in earnest.
Class 4 estimates have an expected accuracy range of 15-30 % on the low side, and 20  50% on
the high side. The scope associated to the estimate range is a recommended practice by the
American Association of Cost Engineering (AACE). 
In the interest of the project's success, Aviation Project Management Group (AVPMG) secured a
second construction estimate, which came in within 10 percent of the original estimate. The first
and second hard construction estimates came in at $189.2M and $207.1M, respectively. These
values should be considered within the same range as above with an expected accuracy range of
15-30 % on the low side, and 20  50% on the high side.


Template revised September 22, 2016.

COMMISSION AGENDA  Briefing Item No. _9a_                                Page 5 of 5 
Meeting Date: March 10, 2020 
ATTACHMENTS TO THIS BRIEFING 
1.  Presentation slides (attached) 
2.  Animations 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
1.  June 26, 2018 - The Commission authorized program development, advance planning,
and project definition for the C1 Building at Seattle-Tacoma International Airport 
2.  July 11, 2017  The Commission authorized a construction contract for the Gate C3 Hold
room Expansion project at Seattle-Tacoma International Airport 
3.  January 26, 2016  The Commission authorized design of an expansion for the existing
Gate C3 Hold room at Seattle-Tacoma International Airport. 













Template revised September 22, 2016.