Lighting designer Nancy Clanton is justifiably proud of her firm's involvement with the Empire State Building's ambitious green makeover. The $20 million budget for sustainable projects—part of the building's major $550 million restoration that began nearly four years ago—is designed to turn the 1931 Art Deco, 102-story icon into a modern LEED Gold skyscraper that has been nipped, tucked, and tweaked enough to achieve an annual 38 percent overall reduction in building energy use by 2013.

Clanton, founder and president of Clanton & Associates, a sustainable lighting design firm based in Boulder, Colo., and her project team tackled the Empire State Building's lighting work, which included creating guidelines for lighting strategies within leasable commercial office spaces, as well as in hallways, bathrooms, and other common areas. Amazingly, though, all the lighting work accounts for just 5 to 8 percent of the building's annual energy use reduction.

If that figure sounds surprisingly low it's because the 2.6-million-square-foot building's biggest energy drain isn't its lighting, which was updated in the early 1990s to more-efficient T8 fixtures, but its inefficient double-hung windows and outdated climate control systems. All of these are being replaced and rebuilt as part of the sustainable makeover.

However, it's impossible to talk about this massive project and single out one sustainable element—be it the lighting fixtures or the 6,500 new, custom-operable windows—because they're all intrinsically linked. “The project wasn't about line items,” Clanton says. “It wasn't about switching out lights or replacing windows, it was about how changing one thing affects everything.”

Changing everything and anything was part of the challenge handed down by building owner Anthony E. Malkin, president of W&H Properties, who asked the team to go for “pie-in-the-sky” during their brainstorming sessions, “There were no sacred cows,” says Paul Rode, project executive with the Manhattan office of Johnson Controls, who oversaw implementation of the building's lighting strategies, alongside heating and cooling projects. Malkin wanted to show the world how an existing building—especially a landmark building—could be transformed, so he encouraged the team to think big. Malkin placed no restrictions on what could be tinkered with to boost the skyscraper's sustainability (although changes affecting the building's aesthetic had to be approved by the Landmarks Preservation Commission), so the team considered more than 60 sustainable strategies before narrowing down the field to eight sustainable focus areas, lighting included. “It took us a year in development to finally get the right combination of things,” Rode says.

The building draws heavily on natural daylight, now that new windows are going in and the intrusive drop ceilings are coming out. This daylighting will be augmented by a mix of direct, ambient, and tasklighting; fixtures with lower power density for reduced energy loads; and glare-reducing LEDs on the observation level.

For leasable tenant space, Clanton and her team prepared lighting packages for prospective tenants that outline what options they will have during fit-out. “Many people put into their rental agreements that they need ‘x' amount of watts per square foot,” Clanton says. “But in reality they never use that much and it's a waste of energy and infrastructure.” Instead, Clanton designed a layered lighting program for them that relies heavily on tasklighting, a combination of indirect and direct lighting, and lighting controls. Her firm's first strategy takes advantage of daylighting by using photo sensors to control ceiling fixtures nearest the windows.

Additional direct and indirect pendant fixtures throughout an office are on dimmers, and the fixtures can be switched off to give tenants direct control over their spaces. Individual tasklighting provides employees with most of their workday lighting, and the fixtures and other nonessential loads are on sensors that switch them off when a workspace is vacated for an extended period of time. Every single light and outlet is monitored by an energy management system integrated into the office furniture so tenants can get feedback on their lighting and plug loads. Not all tenants are submetered, but Rode says that tenants who are submetered are especially receptive to the energy-saving program.

As for the building's corridors and bathrooms: “Gone are the days of lights being on all the time,” Rode says. A Johnson Controls survey of the building showed that during weekends and on weekdays after 7 p.m. the corridors and bathrooms were hardly used. This presented a huge potential savings. In fact, “Most of the energy savings from lighting comes from the hallways,” Rode says. “People don't like it when the elevator doors open and the lights are just clicking on,” he says, so they reached a compromise: both corridor and bathroom lighting is dimmed 5 to 10 percent with sensors bringing the lights up to full brightness when spaces are occupied.

Lighting on the building's 102nd-floor observation level was upgraded to LEDs and tungsten systems that eliminate glare on the windows. Clanton said the previous lighting setup caused so much glare that it often interfered with views of Manhattan—views many thousands of tourists pay good money to see clearly.

What's not being upgraded at the moment is the Empire State Building's exterior lighting—a collection of huge metal halide flood-lights that seem a bit outdated but aren't huge energy drains. (Color filters need to be inserted manually when the building changes its lighting schemes.) “We developed a long-term plan for what exterior lighting they should be replacing,” Clanton says. “I see them eventually going with our recommended LED system, but there's a lot of additional costs. And as for energy goals, exterior lighting was low on the priority list.”

While the lighting packages have all been worked out, the project team is facing another challenge that's preventing them from breezing through the retrofit: access. “What we thought would be a massive lighting retrofit turned out to be something that we have to implement over time as tenants move out and new ones move in,” Rode says. The work is invasive—especially since the new lighting and controls necessitate rewiring of the entire building—but Rode is carefully choreographing all the work. “I've gotten enough done that I'm able to sleep at night,” he says.

Jay W. Schneider is a Chicago-based writer with more than 15 years covering the AEC industry for numerous publications. He has also served on the Construction Writers Association board since 2009.

Shedding Light on Skanska's New LEED Platinum Office The lighting design for Skanska's office on the 32nd floor of the Empire State Building was pretty straightforward: Harness as much daylighting as possible and then augment the natural light with energy-efficient fluorescent ambient lighting and LED tasklighting. And for a bit of whimsy, throw in a few decorative lights (yes, incandescent) over the reception desk and in the kitchen of the 85-person office.

Matt Franks, a senior lighting consultant at Arup, and his team created the layered lighting plan for the 16,600-square-foot office with energy efficiency as their primary goal. Currently, the Empire State Building offers prepared lighting packages for tenants. When the Skanska project began in June 2008, those green requirements had not yet been established, so the building team—which, in addition to Arup, includes design architect Cook+Fox, architect of record Swanke Hayden Connell, engineers Cosentini Associates, and Skanska, which served as contractor for its own space—worked out its own LEED Commercial Interior Platinum program, with lighting playing a key role.

“The space isn't very deep, so there's a ton of natural light and no one is too far from a window,” Franks says. In fact, 90 percent of the office receives natural light thanks to both the removal of the drop ceiling (an update that's happening throughout the high-rise as part of its sustainability renovation) and a floor plan that places glass-front offices at the core of the space and open seating at the four corners. Because the office gets so much daylight, fluorescent overhead lighting levels are low—sensors maintain levels at 25 footcandles—and individual workspaces are equipped with LED tasklighting. “Sometimes there's so much daylighting that lights are shut off completely,” he says. To keep the environment comfortable, windows are outfitted with solar-control shades.

The team only encountered one small challenge during installation. Removing the drop ceilings exposed the building's structure, so the team had to work around massive concrete beams—although they didn't have to work around mechanical ductwork, as the office utilizes an underfloor air system. “Those beams made it a challenge to get lights were we needed them,” Franks says. The solution involved installing more fixtures than would normally be used and spacing them about 6 feet apart, but outfitting each energy-efficient fixture with only one lamp each.

Skanska moved into its new office in January 2009, and the annual energy savings when compared to its former space on Madison Avenue are significant. Their electricity costs per rental square foot now average $1.51 for an annual cost of $36,760, compared to $3.49 for an annual cost of $85,039 at their prior location. Their energy consumption is also down significantly: 141,383 kWh compared to 326,595 kWh.

DETAILS Project Empire State Building Energy Retrofit, New York

Owner Empire State Building Co., New York

Project Advisor Clinton Climate Initiative, New York

Project Manager Jones Lang LaSalle, Washington, D.C.

Energy Service Company Johnson Controls, Milwaukee, Wisc.

Design Partner and Peer Review Rocky Mountain Institute, Snowmass, Colo.

Operations Reviewer Empire State Building Operations, New York

Photographer Bilyana Dimitrova

Project Size 2.6 million square feet

Project Cost $550 million