2023-022 City Hall Building Expansion March 3,2023 Report No. 2023-022
INFORMAL STAFF REPORT
TO MAYOR AND CITY COUNCIL
SUBJECT:
City Hall Building Expansion
BACKGROUND:
On February 16, 2023, Council Member Jesse Davis inquired about a possible expansion of the
O'Neil Ford-designed City Hall building. In the February 24, 2023 Friday Staff Report, staff
provided information related to the construction of City Hall and the probability of the addition of
a second story, including a brief overview related to a preliminary 2013 structural assessment of
City Hall.
As part of the Friday Staff Report, staff indicated that a more in-depth study would be required to
analyze all structural systems to determine if the building's original design would comply with
current code for resistance to seismic and wind load effects, as well as the condition of the entire
building, foundation system, and the building's weathering to evaluate if there may be potential
structural deficiencies. In addition, staff stated that an Informal Staff Report (ISR) was being
prepared, addressing the renovations and analyses conducted by the City over the years in regard
to O'Neil Ford's City Hall
DISCUSSION:
Denton's City Hall was designed by O'Neil Ford and Associates, with the support of structural
and mechanical engineers, Feigenspan & Pinnell and D.W. Torry & Associates in 1967. The
building was constructed as a cast-in-place concrete structure with a concrete pan and joists
foundation over a crawl space. The first-floor columns were constructed of reinforced concrete,
supporting a 10-inch-thick concrete flat plate sealed by rigid insulation and built-up roofing.
Over the years, City Hall has faced constraints due to a demand for public meeting space, limited
and inefficient office space, decentralized service delivery, and increased maintenance cost with
the aging facility. As such, several renovations and analyses has taken place from the 1980s to
2018, which are shared below.
Previous Renovations to City Hall
In the mid-1980s, due to a need for additional administrative space, City Hall was expanded
approximately 5,000 square feet (sf) at its west end. The expansion was a pier and beam
construction, differentiating from the City Hall's 1967 construction as a cast-in-place concrete
structure.
In the 1991 Facilities Analysis Report completed by Corgan Associates Architects, it was reported
that there were limitations for a future one-story addition due to the location of City Hall on a flood
plain and the current parking limitations of the area. Additionally, it was reported that the roofing
had recently been replaced, along with hallway and Council Chambers lighting upgrades.
March 3,2023 Report No. 2023-022
From 1996 to 1998, City Hall underwent additional renovations, split into Phases I and II. These
phases included but were not limited to the removal and replacement of plumbing, relocation of
electrical outlets, removal and replacement of walls and flooring, and upgraded HVAC systems.
In addition, these renovations included furniture layout plans.
Previous Facilities Analyses of City Hall
From 2000 to 2018,the City undertook seven studies related to city facilities,including the current
City Hall.
The following information is related to those seven studies.
August 2001 to January 2002: Facilities Master Plan, Volumes 1-3
Beginning in August 2001 and ending in January 2002, HOK, a global design, architecture,
engineering,and planning firm,assisted the City in the creation of a three volume Facilities Master
Plan. In Volume 1, HOK focused on the present issues with City Hall and discussed potential
options for the expansion or creation of a new City Hall building. The report listed several
constraints with the present City Hall,such as the need for open space preservation of Civic Center
Park(now Quakertown Park); sensitivity to O'Neil Ford's original design intent for City Hall and
the park; and limited opportunities to expand and limited parking development areas.At that time,
HOK provided a series of options for City Hall, included but not limited to building a second story
or horizontal expansion of the current building; acquiring opportunity sites or buildings nearby;
and enhancing McKinney Street by the extension of other development, including redevelopment
or infill of existing commercial establishments along its southern edge.
By January 2002, HOK had determined the need to increase City Hall by an additional 33,000 sf,
with the expansion being constructed on the same level as the existing building or above it, with
no addition allowed above the Council Chambers. The disadvantages that came with this
suggestion was the possible reduction of open space in the park, more traffic congestion on the
site,and would require high sensitivity to O'Neil Ford's original design.Ultimately,the committee
at that time determined that City Hall would remain the administrative center for the City, but no
expansion would be allowed, only simple renovations.
January 2013: Building Facilities Briefing
On January 29, 2013, staff provided City Council with a general overview of the main city public
facilities, reviewing current challenges and space needs, and sought Council direction and
feedback on short-term and long-term facility planning needs. At that time, City Hall's challenges
pertained to the high cost to renovate the building due to architectural integrity, space limitations,
public meeting constraints, parking limitations, flood plain restrictions, and community concern
centered on the building's history.
Discussion took place around O'Neil Ford and Associates four-story tentative expansion that was
produced, but no true clarification was given pertaining to the possibility of the current structure
being able to support additional stories. The only note made was that the additional stories were
not found in O'Neil Ford's drawing specs. There was also the continued argument that parking
would remain limited.
March 3,2023 Report No. 2023-022
As a result of the briefing, City Council instructed staff to perform a space needs study to evaluate
the City Hall structure, identify options and strategies for short-term and long-term space needs,
evaluate City Hall West and the old Fire Central for long-term status, and develop a property
acquisition policy. Another consideration included the consolidation of core city services through
a signature City Hall and Justice Center.
December 2013: City Hall Preliminary Review
In a letter addressed to David Robinson, AIA of Kirkpatrick Architectural Studios from EIKON
Consulting Group, LLC regarding City Hall, EIKON stated that a study of O'Neil Ford and
Associates original Structural Roof Framing Plan indicated that the structure was designed to
accommodate a future second floor of approximately 15,000 sf. In addition, they completed a
limited structural analysis of the concrete and reinforcement, including the pier design and
confirmed that the areas outlined in red in Figure 1 could carry a second story and a new roof
structure, assuming the second floor would be constructed with steel columns and a steel roof
system in lieu of a reinforced concrete system.
n _ .
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= AREA OF FUTURE -
a SECOND FLOOR
I Li
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DENTON CITY HALL-LOCATION OF
FUTURE SECOND FLOOR AS INDICATED
ON THE ORIGINAL PLANS
Figure 1: Preliminary Evaluation by EIKON Consultant Group,LLC
EIKON, based on the drawings, indicated that there did not appear to be any areas indicated for
future stairwells and elevator shaft; therefore, these would need to be additions adjacent to the
existing building or modifications made to the current City Hall. However, EIKON did not
perform a study of the existing mechanical and electrical systems to see how the addition of the
March 3,2023 Report No. 2023-022
second story would impact these systems. Additionally, EIKON stated that they would need to
perform a more in-depth study to investigate the stability of the entire structure after the
installation of the new second story but did state that a"quick review of the original design also
accounted for that issue (increased wind and earthquake loads due to the higher structure and the
need for proper stability to resist these loads)." Staff estimates the in-depth structural evaluation
is likely to cost close to $100,000 to determine existing conditions, connections, and compliance
with current structural codes.
November 2016 to May 2018: Facilities Master Plan Update
From November 2016 to May 2018, the City's HOK Facilities Master Plan was updated.
Performed by Nelson + Morgan Architects, Inc., the plan presented five options to the City in
relation to the expansion or creation of a new City Hall. Each of these options took into
consideration the flood plain constraints, the possible impacts to O'Neil Ford's City Hall, and the
concerns with a proposed detached City Hall Annex.
Below are the five options presented over the year and a half study.
• Option 1: Construct new City Hall southeast of existing City Hall
• Option 2: Construct addition southeast of existing City Hall
• Option 3: Construct new City Hall on northwest corner of Bell Avenue and McKinney
Street
• Option 4: Construct new City Hall on southwest corner of Bell Avenue and McKinney
Street
• Option 4b: Construct new City Hall on southwest corner of Bell Avenue and McKinney
Street, with a new parking garage constructed on the parking lot to the west
• Option 5: Construct new City Hall along S Woodrow Lane just south of the Denton
Facilities Management building
On May 22, 2018, the City Council's consensus was to proceed with Option 1 with an RFQ for
funding for a preliminary design. Based on City records, no RFQ for Option 1 was completed.
STAFF CONTACT:
Cameron Robertson, AICP
Historic Preservation Officer/Principal Planner
cameron.robertson@cityofdenton.com
(940) 349-8532
REOUESTOR: N/A
STAFF TIME TO COMPLETE REPORT: 3.5 hours
PARTICIPATING DEPARTMENTS: N/A