Pasadena City Hall Upgrade & Rehabilitation

From afar, Pasadena City Hall appeared to be aging gracefully, but closer inspection revealed that the structure was at-risk due to a large number of deep cracks and considerable damage to two stair towers and the lantern in the building’s ornate dome. It also had extensive water damage, and a number of its architectural elements needed repair in order to comply with the Americans with Disabilities Act. Additionally, the outdated mechanical, electrical, plumbing (MEP) and life safety systems needed to be replaced.

Structural upgrades included the installation of a base isolation system, which permits building movement during an earthquake, new shear walls, and a “moat” to isolate the perimeter. The seismic isolation process involved removing the original basement slab, installing a new foundation, placing a new floor transfer system, and installing 240 friction pendulum isolators between the foundation and basement level. Subcontractors had to perform this work in very tight spaces with limited access, but the team found creative solutions to the unconventional challenges.

Pasadena City Hall also required a complete interior rehabilitation, including new MEP and fire protection systems and major renovations to building’s plaster ceilings and elevators. Innovative solutions were devised to ensure the historic features were not impacted during the installation of shear walls and upgraded MEP and fire safety systems. Exterior renovations included the refurbishment of cast-stone elements, plaster, and copper cladding.

Safety

The type of construction involved in the retrofit of City Hall was riddled with potential hazards. The basement work, which required moving heavy steel and bulky equipment, had an extremely confined space and tight corners and limited access for multiple trades. The basement slab was a honeycomb pattern of holes and structural openings. As a direct result of Clark's extensive safety program, the Pasadena City Hall project was completed without one single lost-time injury over 540,996 man hours.

Sustainability

Although the project wasn’t originally slated to include green features, the City of Pasadena adopted a Green City Initiative and Sustainability Ordinance and decided to pursue LEED Gold certification for the project. Environmentally-sensitive elements incorporated into the project include an energy efficient central plant, water efficient fixtures, the use of low VOC construction materials, increased bike parking, and employee showers and the purchase of 100 percent green power. Clark implemented a recycling and waste management program for construction debris as part of the green building effort.

Involving the Local Community

Utilizing local residents and businesses on the project was a priority. At the project's onset, Clark and the city established aggressive local workforce and local business utilization goals. The goal of hiring 50 local businesses was surpassed by 32. Similarly, Clark exceeded expectations by awarding $768,000 in local contracts and purchasing $718,000 of locally-sourced materials.

To foster local workforce development, Clark put together a team to develop apprenticeships and seek out local participation for the project. This initiative produced outstanding results with 31 apprentices employed and mentored during construction.

Clark also was mindful of the impact construction can have on residential neighbors. The team regularly communicated with the neighboring church to coordinate construction activities around church events and met personally with residents to address concerns. Clark maintained construction under specific work hours and noise restrictions to minimize disruption of the surrounding community.