Looking at the final results, it’s hard to believe that more than 75 percent of the exterior structure was saved in this renovation of an industrial building. While architecturally dramatic, the transformation is equally impressive for its emphasis on sustainability.

Built to accommodate light manufacturing in the 1970s, the original building in the Southern California town of Irvine was made of concrete and had tiny clerestory windows. When the property came on the market at the end of 2007, The Koll Co., a local real estate developer, saw the potential to transform it into premium office space. Despite its antiquated architecture, the two-story structure had underground parking, a prized amenity in Irvine’s sunny climate.

“We had already made the decision as a company to go green because it’s the direction development should be going,” says Scott Meserve, Koll’s development manager. “We didn’t think it was going to help with the prices we could command, but we certainly saw it as a way to distinguish ourselves in a crowded market.”

For its first foray into sustainable development, Koll brought in LPA, a Southern California architecture firm with extensive experience in LEED buildings. The decision to seek LEED Silver Core & Shell certification was fairly easy. Before any architectural interventions, the building had LEED-friendly attributes such as a location close to bus lines and subterranean parking to reduce the urban heat island effect.

To bring the rest of the puzzle together, LPA knew that the existing architecture would have to change pretty dramatically. Making the switch from industrial to office space meant that the architects had to take the building’s existing 62,000 square feet down to 40,000 square feet in order to meet the city’s parking space requirements. The second story was an obvious candidate for removal. Working with the remaining square footage, however, would require thinking outside of the box.

“The building was square, which is not good for an office. Ideally you want a thin, rectangular floorplate, so you can bring daylight in,” says LPA architect Keith Hempel. The remodeled building, now the Koll Airport Professional Center, has an H-shaped floor plan, with open-air entry courts that have been carved out on either side. The two resulting rectangles, which can be divided into as many as four individual suites each, are daylit by exterior windows as well as the entry courts’ glass wall. In the center of the building, the original restroom core was retained and modernized.

The design team kept costs down through strategic choices of design and materials. The key new elements, the entry courts, are covered by aluminum canopies. The canopies’ louvered fins shade the sun coming into the glass-walled suites, reducing heat gain. These same canopies supply cross-bracing, so structurally the building functions as a single unit. “Normally when you cut into a building, you have to add steel to stabilize it along the new edges,” Hempel says. “So that was one way we were able to save money.”

The design team also found ways to open up the exterior of the building without using lots of expensive steel. “When retrofitting a concrete tilt-up panel with windows, you used to have to work around the rebar or put a lot of steel around the perimeter of the window to give back the strength,” Hempel says. “Using carbon-fiber mesh to reinforce the concrete [after cutting through the existing rebar], we were able to achieve those big openings in a cost-effective way.”

To bring in light but minimize heat gain, the large glass windows have deep insets and, in some cases, vertical sunshades. Because the morning and late afternoon sun are both quite strong, the vertical shades block the sun at lower angles on the building’s western and eastern exposures. Low-E glass, a white PVC cool roof, and high-efficiency lighting all are part of the building’s strategy to exceed California’s benchmark-setting Title 24 energy code by 17 percent.

“It was a very exciting project for us,” Hempel says. “Someone who went for a more conventional approach would have put a lobby on one side and connected everything up with an interior corridor, and that would have been it. But the spaces would have been dark and uncomfortable for people on a day-to-day basis. So it was great to be able to improve the structure by maximizing daylight for all the tenants, leading to an architecture that is really unique.”

Lydia Lee writes about design and architecture from Menlo Park, Calif.

Green team

Architect, structural engineer, landscape architect: LPA Inc., www.lpainc.com
Client/owner: The Koll Co., www.koll.com
Mechanical engineer: TKSC Engineering, www.tkscengineering.com
Electrical engineer: Konsortum 1, www.konsortum1.com
Civil engineer: Walden & Associates, www.waldenassociates.com
General contractor: Pacific Construction Group, www.pacificconstructiongroup.com

Materials

Adhesives, coatings, and sealants: Mer-Krete Systems, www.merkrete.com; Dow Corning,  www.dowcorning.com; 3M, www.3m.com; Design Polymerics, www.designpoly.com; DAP, www.dap.com; NewLook International, www.getnewlook.com
Concrete: Robertson’s Ready Mix, www.rrmca.com
Flooring: Arizona Tile, www.arizonatile.com
Glass: Oldcastle Glass
Gypsum: CertainTeed, www.certainteed.com
HVAC: Trane, www.trane.com
Insulation: Certainteed
Lighting control systems: Watt Stopper, www.wattstopper.com
Lighting: LSI Industries, www.lsi-industries.com; Sistemalux, www.sistemalux.com; Liton, www.liton.com; B-K lighting, www.bklighting.com
Masonry: ORCO CMU, www.orco.com
Metal louvers: Airolite Co., www.airolite.com
Mechanical screen: Metecno-Morin
Paints and finishes: Frazee Paint
High-performance coating: PPG, www.ppg.com
Plumbing and water systems: Symmons; Sloan Valve Co., www.sloanvalve.com; Kohler; Mueller Industries; Tyler Pipe, tylerpipe.com; Rheem, rheem.com; Zurn