Sustainable Classic
The Empire State Building was a marvel when it debuted as the world’s tallest building in 1931. Built in 18 months, the 102-story building kicked off a race for urban construction heights that continues today.
It’s only fitting that a recent $4.6 million fit-out in the building may set the benchmark for what it costs, what it takes, and how much can be saved in the long haul by creating a LEED CI Platinum office in an existing building, much less a landmarked skyscraper. That’s because the 32nd floor is not just home for Skanska USA’s New York office – it’s also meant as a showcase for high-end yet achievable sustainability.
“There are a lot of clients that say, ‘I’d love to build green, but it costs too much,’” says Steve Pressler, executive vice president and area general manager of Skanska New York. “But we have kept meticulous records to show them that we could build it for not much more than a regular class A space, to prove to people that in dollars and cents they will save more in the longer term.”
Skanska decided to pursue the top LEED status from the United States Green Building Council even before it picked the tower for its new home last year, moving over from Madison Avenue. The construction company had lined up its design team early to hash through the LEED checklist, and it became clear any existing space would do, Pressler says.
But the Empire State still offered several advantages. “Its original design was inherently green, thanks to how it relied on daylight and natural ventilation,” Pressler says. It also helped that the building’s owner, W&M Properties, became a booster.
The proof is in the finished product – a 24,400-sq-ft space yielding 44 LEED points, more than enough for Platinum on the 57-point scale. Pressler says the construction effort clocked in at $210,000 more than regular Class A office construction, or a “Platinum premium” of 4.7%. But the net present value of savings from 46% lower projected energy costs over the 15-year lease adds up to $556,436. After accounting for the premium and a green projects grant the team won, Skanska gains net savings of $368,380 over the lease term. And that’s using conservative energy savings estimates, Pressler says.
Skanska is already logging energy savings over its prior 15,500-sq-ft space, which housed only two-thirds of the current 80 staffers, he adds.
Pressler says the marketplace still shows “interest but hesitancy” about green construction, in some cases because of completed projects that have come up short in energy savings. He says most cases involve owners not properly using their green building systems.
Hitting high sustainability goals was of utmost importance for Skanska in order to prove the value of sustainability to clients, says Rick Cook, partner at Cook + Fox, an architecture firm whose own offices became the first LEED CI Platinum project in New York several years ago. He says the key is to maximize advantages you have and to stay committed.
“You try to harvest the best qualities of the original space, and only bring healthy materials inside, and apply the...
...best of modern technologies to the workplace,” Cook said. “It became a very interesting challenge to see if they could do the healthiest of workplaces in a Jazz Age skyscraper.”
Pressler says so far, the space completed a year ago has secured several leads, including an invitation to bid on the fit-out of a large tenant moving into the Empire State Building.
Fast and Functional The fit-out showcases not only Skanska’s green goals but the team’s efforts to build the space quickly, create a practical space, and salute the classic building’s stature.
Pressler says the lease contract’s six month rent-free period offered a carrot to work fast. Planning began immediately, featuring an early day-long charrette bringing together all of the design team to figure out which sustainable goals were possible.
The tight timeframe and strict budget were among challenges addressed in the charrette, organized by Terrapin Bright Green, says Jason King, a project manger at the design consultant, which is affiliated with Cook + Fox.
King says charrette ideally take place early in the design process, allowing the team to consider all green options. It’s hard to go back and try to incorporate green goals in a completed design, he adds.
Another key goal for charrettes is to have as many project participants present, including engineers and subcontractors. “And it helps to have clearly stated environmental goals at the outset,” King adds. “Then you can get into the details of the green strategies, and they stay in the mind of the whole team as you go along.”
The Skanska charrette delved into the possibilities of alternative HVAC systems, says Scott Ceasar, senior v.p. at Cosentini Associates, an M-E-P engineer in New York. The discussion ultimately ruled out the newer concept of “chilled beams” that radiate coolness to an interior space because of humidity control concerns caused by the building’s height and limestone façade, not to mention the higher cost. The charrette members also deeply discussed the eventual choice of a raised-floor air distribution system, including challenges posed the by the older building’s lower window heights and a topping slab that reduced floor-to-ceiling heights.
“It was a complete blue sky exercise,” King says.
Pressler says the construction effort began not long after, and ran 11 weeks, a month shorter than a typical effort. The team also managed to get New York City Landmarks Preservation Commission approval for design modifications to the building’s exterior to help install the HVAC systems.
“Probably the biggest challenge for us was the construction frankly,” Pressler says. “Even though we had ordered a lot of things early, they were coming late.”
The end design builds around orienting concepts of the classic tower, such as the core’s 67 elevators in different banks flanking central corridors. The team won LEED points by not stripping down this space but instead reusing most of it with a “racetrack-style” hallway configuration.
The design also used the four larger useable spaces at each corner of the floor to create a thematic connection to the city by points north, south, east, and west.
“You’ve really connected the interior space of the Empire State Building with the city that it’s part of in a way that hadn’t existed before,” Cook says.
Each quadrant houses workstations for entire teams, such as the southeast corner’s base area for the...
...marketing team or the northwest section’s space for the corporate commercial development unit Skanska recently brought to the U.S. Along the corridors connecting the quadrants are 21 private offices for senior executives.
The space also includes conference rooms stacked alongside each other with glass walls, with shades for privacy, as well as a kitchen, training rooms, private telephone nooks, and other functional spaces throughout. Most rooms have glass walls to maximize daylight exposure.
Green to the Core The project’s Platinum LEED status owes to a host of water, energy, sustainable material, air quality, and other innovative design features. Probably the biggest contributors were lighting and air management schemes.
The lighting systems take advantage of the giant windows. Pressler says over the years, many tenants installed HVAC systems in overhead ductwork, which also led to adding dropped ceilings blocking out the top fifth of the windows. The new space removed these elements to regain full window exposure with exposed ceilings.
That helps daylight reach 90% of the office, including interior corridors, and gives 99% of employees an outside view – both of which add LEED points.
Skanska then installed a high-end lighting system that uses 35% less energy than ASHRAE standard minimums. It features sensors for individual light fixtures to monitor daylight levels and adjusts bulbs accordingly, so on most days fixtures closer to the windows can run dimmer. The system also features motion sensors that turn off lights in empty offices and automatic, timer-set low-voltage motorized window shades that maximize natural light but also control heat and sun glare. Pressler says the systems have manual overrides.
The HVAC system features four air towers, one in each quadrant, that take in chilled water from the building as well as exterior air. Those towers distribute pressured air through the raised floor plenum to the workspaces. A LEED-friendly feature are individual diffusers, or vent control covers, allowing users to regulate how much air comes into their workstations, and therefore control temperature. The diffusers, built into the carpet tiles, can be moved easily.
Cosentini’s Ceasar says the raised floor system took special planning because of the building’s already low floor-to-ceiling heights and the topping slab. The solution was choosing a 10.5-inch height instead of the normal 12 in, while digging trenches into the topping slab to run conduit for most electrical wiring and cabling. He says four-tower system is unconventional but more efficient than pushing air from a central unit to the whole floor.
Ceasar says floor-based systems are more efficient because in the cooling season you can pump air at 63 to 67 degrees Fahrenheit that will rise upward. Overhead systems instead force down air at 55 degrees just to reach occupants against the natural upward flow of warmer air.
Pressler says the raised floor is accessed by stairs and ramps lowering to the base floor level at the core...
...for access to the elevators, bathrooms, and central lobby.
Other energy-saving features in the space are waterless urinals, hand-sensor faucets, and low-flow toilets in the bathroom that reduce water usage by 40% below Energy Policy Act standards. And the space has submeters for electric, chilled water, and steam usage to help Skanska track usage.
Other sustainable elements that helped Skansa hit the mark are:
• low-VOC paints, adhesives, and finishes for better air quality
• cork for flooring and paperstone – recycled, compressed paper that forms a durable surface – for kitchen tabletops and workstation furniture
• Forest Stewardship Council-approved wood-based materials
• recycling of 80% of construction waste
• procurement of 28% of materials from manufacturers within 500 mi.
Pressler says the experience has sparked interest by the building’s owners, who believe Skanska is using less than a third of the standard 6W per sq ft of electricity called for in most tenant contracts. “That could really reduce the need for extensive electrical infrastructure,” he says.
And in the bigger picture, Skanska is contributing to “marketplace transformation,” Cook says.
“Somebody has to take a leadership role and do the hard work to be the first, the second, the third,” he says. “At some point these become standard practices.”
Key Players:
Tenant, Construction Manager: Skanska USA, Parsippany, N.J.
Architect: Cook + Fox Architects, New York
Programming Architect: Swanke Hayden Connell Architects, New York
M-E-P Engineer: Cosentini Associates, New York
Lighting Design: Arup, London
LEED Charrette Coordinator: Terrapin Bright Green, New York
Building Owner: W&M Properties, New York
