Denver’s GE Johnson Construction Co. is well under way with the transformation of the César E. Chávez Memorial Building in Denver into a state-of-the-art, high-performing green building—one with an entirely new skin over its 1982 bones.
The $37.4-million project, funded by the 2009 American Recovery and Reinvestment Act, completely replaces the exterior skin on the 10-story, 147,156-sq-ft office building that houses five federal agencies, including the Social Security Administration, Dept. of Agriculture, Government Accounting Office, Dept. of Justice and the Dept. of Education.
The building, which has frequently been dubbed one of the ugliest structures in the city by various media outlets, is getting a facelift to be “more responsive to the urban context and the local community in which the building resides,” according to design-build team member Tryba Architects of Denver. The new façade will balance the traditional design principles of proportion, massing and scale with the modern expression of program, structure and enclosure, designers said.
The project, which also includes an HVAC upgrade and a new parking garage just north of the building, is being done while the building is fully operational, under the watchful eye of the owner, the General Services Administration.
“At GSA, we're constantly looking for ways to streamline processes and reduce the cost of construction projects to benefit both our federal agency customers and the American taxpayer,” said GSA Rocky Mountain Regional Administrator Susan Damour. “The team's unique approach for replacing this building's exterior skin enables the nine agencies and nearly 350 building tenants to remain operational during this extensive modernization. That’s ‘money in the bank’ when you consider that most projects of this magnitude require tenants to move into temporary space during construction.”
Allowing tenants to remain in the building during construction is saving more than a $1 million in relocation costs, Damour said.
Phase 1 of the project is more than 50% complete and includes replacement of the adjacent parking garage. The new seven-story, 293-stall garage will feature one of the project’s sustainable features, a solar sculpture capable of producing 115 kW of renewable energy, offsetting both the building’s energy consumption by 5% and reducing domestic hot water grid energy by 30%. The new garage has better sightlines, cross ventilation and easier navigation that includes occupant-sensor lighting and online maintenance updates, architect David Tryba said.
Replacing the building’s exterior skin marks Phase 2 of the project. An energy-efficient, custom curtain-wall system has been designed for each façade. Based on sun and solar studies and simulations of all seasons, the new curtain wall will reduce heat gain from sunlight. The combined system will reduce energy consumption while providing a protective and distinctive exterior for the building.
The new façade is comprised of prefabricated, 15-ft-wide, two-tone aluminum panels that meet new federal standards for waterproofing, energy efficiency and blast resistance, said Mark Sheldon, project manager for Tryba Architects.
“This project sets an exciting precedent because of the lessons that will be learned from deconstructing the old skin while sequentially constructing the new one,” Tryba said.
“We are constructing a temporary barrier wall system inside the tenant spaces that allows for the construction team to remove the existing façade from the exterior,” added Dan Seib, construction manager for GE Johnson Construction. Even the temporary barrier wall system is more energy efficient than the existing building façade, he said.
Approximately 50% of the building’s temporary barrier walls have been installed, allowing for exterior skin demolition on the north side of the building, with crews moving from east to west. Deconstruction will take about six weeks per side with another six weeks per side to install the new façade.
Sheldon said that the project schedule calls for all four sides to be completed in about seven months.
The modernization project also incorporates state-of-the-art, energy-efficient variable air volume-based mechanical systems with full digital controls, new electrical, lighting and water-saving plumbing systems. When complete in late 2012, the modernized building is expected to cut its building energy use by 30% and produce 5% of its energy through on-site renewable-energy technologies.
Interior upgrades include an expanded and fully redesigned building lobby and a new security entry. Other project elements involve: