April 27, 2022
MEMORANDUM
TO: Mayor Paul and City Council
RE: City Hall Seismic Assessment and Proposed Project
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Background
City Hall was built in 1965 in accordance with the 1964 Uniform Building Code (UBC). It was remodeled in 1986, but the project did not modify the structural system to meet the 1985 UBC. Various Structural Analysis Reports performed in 2011, 2012, 2014 and 2021 documented that the building does not meet current building standards, including seismic safety standards (see Attachments A - E). In addition, City Hall is designated as the City’s Emergency Operations Center, and there are concerns that the City’s response to a seismic event would be significantly hindered due to the structure being unusable in the aftermath.
The 2012 Civic Center Master Plan Structural Analysis Report also identified that much of the mechanical, electrical, and plumbing (MEP) equipment is beyond its useful life. Other aged systems include communications, data/IT, accessibility, sprinkler, and smoke/fire alarm. Findings from the 2012 Structural Analysis report are consistent with the current state of the building.
As of January 2022, approximately 130 Staff are stationed in the building. Staff expansion since 1965 has created a need to renovate the interior for increased efficiency, including improved public counter access, and sufficient, flexible spaces for work and conference rooms. Renovation of the interior with sufficient, flexible workspaces as well as more efficient public-facing Staff/Community meeting spaces and public counters, are needed. Parking capacity also continues to be an ongoing concern.
The current “City Hall and Community Hall Improvements - Programming and Feasibility” project was initiated in FY 2021-2022 with $500,000 approved to form the basis of a renovation strategy for the buildings. A new CIP project entitled “City Hall Renovation/ Replacement and Library Parking Garage” is proposed for the 2022–2023 CIP Program. Staff is requesting $4 million in funds for this project in the 2022-2023 CIP so that planning and design can continue.
Civic Center Parking
Because seismic work at City Hall triggers a requirement to address long-standing parking issues at the Civic Center, a parking structure is included in the new project.
The Civic Center Parking Analysis published in 2020 by Kimley Horn describes the deficiency of parking at the Civic Center in detail. This report is based on observations of traffic patterns and use and concluded that Civic Center parking is deficient by 185 parking spaces. Similarly, Building and Planning Code requirements, determined by building area and occupancy types, indicates that the Civic Center is currently deficient by approximately 200 parking spaces.
Seismic Concerns
The importance of a full seismic retrofit of the City Hall building has been stated in past studies and reports to City Council. Most recently, the 2021 Structural Analysis was prepared by MM & E Engineers. See Attachment A.
In the words of the MM & E Engineers who conducted this recent analysis:
“The structural deficiencies noted in this report indicate that the building is likely to sustain major damage and not be functionally operable if a significant seismic event were to occur. If damaged, timely delivery of services to the community that are provided using this building would be impacted. Additionally, occupants of the building (public and staff) are at a higher risk of injury compared against a similar occupancy in a building that did not have these deficiencies.
Based on a review of the existing design and subsequent evaluation reports, the current building is very vulnerable to seismic damage. The original design from 1965 was before vast improvements in the science of earthquake engineering was incorporated into the building codes. The extensive remodel in 1986 failed to bring the building into conformance with the improved seismic codes at that time. The building relies on concrete shear walls for lateral load resistance and a combination of concrete walls and isolated concrete columns to support the gravity loads. These elements do not have sufficient ductility to resist seismic lateral displacements without sustaining significant damage. Damage to these critical structural gravity load-resisting elements could result in collapse of the roof structure. The life safety and economic risk could be substantial.”
Specific findings from the Structural Analysis include:
Upper-level concrete shear walls overstressed up to 150% Anchor bolt connections overstressed up to 26%
Roof diaphragm overstressed up to 176%
Roof connections overstressed up to 35%
Concrete column ties inadequate in size and number
Equipment anchorage capacities unknown
Options
The City considered both renovation of the existing 24,000 SF City Hall and replacement of City Hall with a new 36,000 SF building. Preliminary programming indicates that 36,000 SF is optimal for current and projected needs, in addition to space that will be provided at 10455 Torre Avenue. Both options include a new three-story above ground parking garage adjacent to the Library which would include approximately 200 parking stalls. Estimated costs for the two options are outlined below.
OPTION A
City Hall Renovation (24,000 SF) + Library Parking Garage $ 4,000,000 FY22-23
Planning and Design
$ 21,600,000 FY23-24
Parking Garage Construction
$ 34,300,000 FY24-25
City Hall Design/Build
City Hall Renovation will address seismic, infrastructure, and ADA upgrades. Exterior work would include roofing replacement; column demolition/ replacement; window replacement; shear walls stiffened. Interior work would include demolition and replacement of interior walls to accommodate new layout; replacement of elevator, mechanical, and electrical systems; and bathroom remodeling to increase required fixture counts and update plumbing. This option does not increase the square footage of City Hall, therefore additional office space would need to be identified and acquired to accommodate current and future staffing needs.
OPTION B
City Hall Replacement (36,000 SF) + Library Parking Garage $ 4,000,000 FY22-23
Planning and Design
$ 21,600,000 FY23-24
Parking Garage Construction
$ 54,000,000 FY24-25
City Hall Design/Build
The proposed replacement of City Hall would provide an additional 12,000 SF of space to accommodate current and future staffing needs along with conference rooms that could be used by the community. The building would be fully code-compliant building and would further the City’s sustainability goals by replacing one of our most energy-intensive facilities.
Funding Request
As stated above, staff is requesting $4 million in the 2022-2023 CIP program so that planning and design can continue. It is anticipated that staff would come to Council in early 2023 with a request to decide on: 1) City Hall Renovation or Replacement based on conceptual plans and updated cost studies; and 2) Approval to move forward with the Library Parking Garage; and 3) Proposed project funding scenarios. _____________________________________
Prepared by:
Susan Michael, Capital Improvement Programs Manager
Matt Morley, Public Works Director
Reviewed by:
Dianne Thompson, Assistant City Manager
Attachments:
A - 2021 City Hall Tier 1 Seismic Eval
B - 2014 Seismic Study Tipping Mar
C - 2012 Essential Serv Fac Analysis AKH
D - 2011 Structural Analysis AKH
E - 2006 Seismic Report AKH
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Attachment G