CHANDLER CITY HALL
ARCHITECTURAL ENGINEERING SENIOR THESIS PORTFOLIO
While great efforts have been taken to provide accurate and complete information on the pages of CPEP, please be aware that the information contained herewith is considered a work-in progress for this thesis project. Modifications and changes related to the original building designs and construction methodologies for this senior thesis project are solely the interpretation of Stephanie Romanias. Changes and discrepancies in no way imply that the original design contained errors or was flawed. Differing assumptions, code references, requirements, and methodologies have been incorporated into this thesis project; therefore, investigation results may vary from the original design.
This page was last updated on 09-11-2010 is hosted by the AE Department © 2010
Building Name: Chandler City Hall
Location and Site: Chandler, Arizona
Building Occupant: City of Chandler employees and guests
Occupancy Type: Mixed Use: Government, Office, Council Chamber, Gallery
Size: 137,692 sq. ft.
Number of Stories: 5 stories: Main Lobby, Vision Gallery, Council Chambers-1, City Clerk tower-5
Primary Project Team:
Owner: City of Chandler
General Contractor: Sundt Construction, Inc.
Civil Engineer: Dibble Engineering
Structural Engineer: Caruso Turley Scott, Inc.
Landscape Architect: GBTwo Landscape Architecture
Mechanical Engineer: SmithGroup
Plumbing Engineer: SmithGroup
Electrical Engineer: SmithGroup
Lighting Design: SmithGroup
Dates of Construction: May 2009 – October 2010
Cost: $47 Million
Project Delivery Method: Design Bid Build
In efforts aimed provide a new “urban edge” to the city of Chandler, Arizona, Chandler City Hall reflects the idea of respecting the past and acknowledging the future. The city clerk, communications and public affairs, a Vision gallery and the Council Chamber compose the majority of the building. Timelessness is the essence created within Chandler City hall by reinstating the past and expressing the technology of the future.
Connecting the single story elements of the building, the plaza encourages activity and interaction. These stone single story elements encompass the historical content and natural scale of the area. However, the Council Chambers and tower provide that link to technology driven future. Spanning the plaza and towering over the lower single story stone portions, stands a tall floating glass box. Beneath this floating glass box exists a mezzanine roof top plaza for events and socializing. These components though serve to frame and unveil the iconic Council Chambers which acknowledges a new identity and future for the City of Chandler.
Major National Model Codes:
International Building Code (IBC) with City of Chandler Amendments- 2006 Edition
Chandler City Hall’s new location resides zoning district C-2, the Commercial Community District. This site has also been named in the CCD, City Center District, and PAD, Planned Area Developments zoning districts. According to the C-2 zoning stipulations a setback of 50 feet from the main arterial streets is required and the building is permitted to occupy up to 55% of the lot area in Commercial Community District. The Planned Area Development and City Center District guidelines give the authority to the City Council overrule the height restrictions set forth by the C-2 stipulations if deemed appropriate to the building design and impact. Following review of the regulations permitted by the zoning ordinances and increases per IBC 2006 with City of Chandler amendments, the City Council has allowed for an unlimited maximum area, a maximum allowable height of 180 feet, a maximum of 12 allowable stories. Chandler City Hall stands 5 stories high 90 feet above the ground at its highest point. It occupies 54% of the lot area between Arizona Avenue and Washington Street spanning across the more pedestrian accessible Chicago Street.
Historical Requirements: Not applicable.
Stone veneer lines the lower single story portions of Chandler City Hall, creating a character and natural scale for the building. The tower portion however stands tall and transparent, encompassed by a glass curtain wall. Linearly the height of the building is expressed by stainless steel panels running down the building, then turning inward serving as a canopy ceiling before extending into the lobby as a ceiling element. Displaying the Vision Gallery and transitional spaces, glass curtain walls line the public spaces within the building. Unlike the other glass portions of the façade, the Council Chamber’s exterior provides a translucent aesthetic.
Practical, yet artistic, the west façade of the tower boasts a Ned Kahn art scrim. An array of perforated pieces of stainless steel set out from the façade overlay the glass curtain wall serving as both shading and artistic purposes. With the wind, these panels sway in creating a wavelike movement across the scrim.
Overall, the flat roof system of Chandler City Hall utilizes a PIB (polyisobutylene) single ply roofing membrane. Nearly tripling its breaking strength, the PIB membrane is coupled with a non-woven synthetic fleece backing. The white option for the PIB membrane was chosen to help mitigate the heat island effect. The PIB membrane covers the entire roofing area, however, it is topped with a concrete paver to serve the needs of public use on the mezzanine roof plaza.
Indoor air quality is significant to the building design and was also maintained both during construction and before occupancy. Water efficient landscaping went into the plaza design and sustainable efforts were made to reduce the heat island effect; essential in the Arizona climate.
Chandler City hall is comprised of several materials that contribute to sustainable design. Certified wood was used for millwork and other wood feature within the building. The stone components are golden gate quartzite which was extracted from a local quarry. Additionally, a significant amount of glazing allows for the utilization of daylight. This is coupled with a series of shading devices used to control daylight integration. Several materials used in the design are comprised of a recycled content. This includes both the glazing and steel components used in the building design.
Breaking ground in May 2009, construction process was full under swing. Throughout the construction process great efforts were taken in attempts to achieve a LEED Gold rating upon completion. Additionally, during construction, the design professionals deemed it of high importance to mockup several materials and component on both the exterior and interior of the building to verify the appropriate effect would be achieved. Chandler City Hall is still currently under construction with an estimated completion and grand opening scheduled for December 2010.
Chandler City Hall utilizes a combination of a cast-in-place concrete system in some areas and a steel framing system in others. The foundation system of the building is a 4” thick concrete slab over a 4” aggregate base course with a combination of deep caisson footings, continuous wall footings, and isolated footings where deemed structurally appropriate. On the upper floors of Chandler City Hall, 6-3/4” slabs are typical with 8” slabs at the bridging portions from the elevator lobbies, and 10” slabs at the west end of the building. Thickened slabs of 16” are used along the column lines of the upper floors. The structure for west side of the 5 story portion of the building also utilizing a concrete bracing frame in the design which doubles as a structure component and an aesthetic along the lower portion of the west exterior façade.
Utilizing a combination of variable air volume and constant volume systems air is circulated throughout Chandler City Hall. A total of thirteen air handling units are used between the north and south buildings of Chandler City Hall. Supplied by a chiller and cooling tower on the south building and parking garage a hydronic system supplies cool air to the building which is distributed by a variable air volume system as the main distribution with a constant air volume as the secondary distribution system for use in only a few spaces within Chandler City Hall.
Electricity for Chandler City Hall is supplied by Arizona Public Service. Utility owned pad mounted transformers step down the primary voltage service to a 480Y/277V system for the building. 3000A and 2500A switchboards supply power to the north and south buildings respectively. Chandler City Hall has implemented an emergency system to supply life safety loads in the case of a power outage. A 750kW diesel generator is the main source of electricity for this system. First supplying the emergency distribution panel, this panel then serves two other distribution panels that supply power to the branch circuits of the life safety systems of Chandler City Hall.
With maintaining energy efficiency in mind, Chandler City Hall has created a lighting design solution reinforcing its architectural concepts from the outside in. A range of sources including fluorescent, metal halide, halogen, and led sources are used in the lighting design of Chandler City Hall. Typical lighting loads are serviced by a 480Y/277V system. However the lighting in the Council Chamber and Vision Gallery utilize power from the 208Y/120V system. With complex lighting and control systems both of these spaces the lower voltage is used as they are fed from dimming panels. There are programmable controls for these spaces in order to have appropriate lighting scheme for a particular event that may occur. Additionally, having a glass façade on the upper office floors, plans to harvest daylight in this space through use of a roller shading system.
Additional engineered systems that supply Chandler City Hall include voice/data, and cable. The building is equipped with audiovisual capabilities in many of its areas but is particularly important in the Council Chambers where a variety of different events could potentially occur. These capabilities are also fed to office conference rooms and the mayor’s conference space.
Chandler City Hall has a security system in which surveillance cameras have been installed within several of the corridor and publically accessible spaces. Additionally, for more high security areas, doors are equipped with card readers on accessible to specific personnel.
Rendering Courtesy of SmithGroup