Harvard University had to expand and WGBH had to find a new home. What could have been a crisis for the nationally known public broadcaster was turned into an opportunity to create a state-of-the-art sustainable complex from below ground to its rooftop.

“We were a 57 year-old organization housed in a facility built in 1964 and expanded over the years to include twelve smaller buildings, none of which were very inspiring,” said Chris Pullman, WGBH Vice President of Branding and Visual Communication. “When we set about to determine our goals for the new site, we came up with half a dozen key objectives. Among them was to make this new facility as green and sustainable as we could afford to make it.”

The result is the $85 million Brighton studio complex—funded through a capital campaign, and the sale of WGBH’s property to Harvard. Certified through the USGBC’s Leadership in Energy Efficient Design (LEED^® ) program, the complex enjoys a host of sustainable features, including a greenroof and an innovatively financed, 100kw solar-energy array.

“An investor helped pay for the capital costs of the solar system in return for taking a tax credit for the next seven years, at which time WGBH would pay for the solar array and ownership would revert to us,” Pullman said. “This is an interesting way for companies to leverage the opportunity to install a system that will give them the energy payoff right away and allow them to afford it.”

Opened for operation in 2007, the pubic broadcaster’s green features have been widely recognized. It is one of, if not the first facility in New England to combine a solar-energy system with a greenroof and the greenroof is currently the largest in Boston. The building has been recognized by the city’s mayor and the American Institute of Architects (AIA) as one of the “greenest” in Boston and it has become a very popular draw for visitors.

“We’ve had more than 16,000 people through the building since we opened last September,” Pullman said.

An Opportunity and a Vision
As the new millennia began, Harvard University found itself with a growing need for space. The former WGBH studio complex was right next door and in the middle of the university’s eventual master plan.

 “Once faced with the need to move, we recognized the opportunities that this presented us,” Pullman said.

As a non-profit public broadcaster, it was important to make the new facility as accessible as possible to the public, and especially for the 170,000 people who donate to its operation every year. Accessibility had been a challenge at the previous site. That mindset evolved into discussions of how to make the new facility an example of a successful and sustainable commercial project.

Planning began in 2001 and design work on the new complex got underway in 2002. It culminated in a 345,000 square foot complex, half of which was contained in an existing structure.

The organization purchased the building, which had never been occupied due to the economic downturn early in the decade. An additional building to house studios was constructed across the street on a former brownfield site and the two were joined by a connecting 480-foot by 50-foot, two-story high structure.

With an eye on LEED certification, the new construction was completed with 90 percent recycled steel. The new studio complex features motion-sensitive office lighting, UV-filtering glass and motorized sunshades on some windows to help conserve energy, while waterless urinals and dual-flush toilets will decrease water consumption by as much as 30 percent.

On the ground, care was taken to decrease the impact of construction on the surrounding environment. Thirty-six trees were planted around the studios and a rainwater retention tank was installed to allow stormwater from the site to slowly infiltrate the soil rather than rush into the city’s storm sewer system. Additionally, retention chambers were installed under plants and ground cover to further enhance stormwater collection and infiltration.

On the roof, initial plans went in several directions.

“To start off with, we wanted a greenroof and we wanted solar,” said Dave Norton, WGBH’s Physical Plant Director. There were also discussions about wind energy generation.

“We produce television and radio programming about the state of the environment and new energy technologies — so this was a way for us to put our money where our mouth is,” Norton said.

Financing the Plan
The primary challenge to achieving the rooftop combination was financial. Neither the solar energy system nor the greenroof were included in the building’s budget, so Norton helped find the funding. A $57,000 grant from National Grid covered the cost of the greenroof, but the greatest expense was the solar array.

A quarter of that component was provided by a $250,000 matching grant from the Massachusetts Technology Collaborative. The organization had turned down the request when it was first approached in the early days of the project, but later changed its position.

“One of the reasons, I think, is that solar is one of the most proven of modern energy technologies. We were able to get them to give us one of their largest grants last year,” Norton said.

The next challenge was to come up with the remaining 75 percent of funding. Norton tapped into an experience he had two decades ago, when he was able to work with a utility company to build a new mechanical plant for the station. The arrangement allowed that utility to own the plant for the first six years, and pay for it through depreciation and shared operating costs.

“In California, third-party ownerships are very popular because there are some very good tax incentives from the state,” said Norton, though such incentives are not on the books in Massachusetts. “However, you can get some federal tax credits and accelerated depreciation from the IRS, if you have a system that is large enough to make it worthwhile for an investor group to become interested.”

An investment group in California, which was involved in such solar energy systems, agreed to back the project and initially own the array.
“They had to take possession of it before we had an interconnect with the local utility. It had to pass all the scrutiny of an IRS audit,” Norton said. “They own it. They maintain it. They service it. We are just the host of the facility.”

The financial arrangement spans 25 years, but the key component is that WGBH will buy back the array in seven years.

“We lease it from them, pay them a pre-negotiated, set-amount per kilowatt hour, and we guarantee that we will use all of its power, which is not a problem,” he said.

Putting it all Together
The rooftops of the new WGBH complex span 25,000 square feet. Of that, approximately 4,000 square feet is covered with solar panels which are surrounded by a total of 5000 square feet of greenroof. A 60mi. rubber roof membrane spans the entire roof surface.

Portions of the roof structure had to be reinforced to accommodate the added weight load. The planting media for a greenroof is much lighter than natural soil, but still accounted for approximately 53 tons of additional weight. The effect of wind on the solar panels was also an issue to be addressed.

“It’s not a tremendous factor, but you are adding something to the roof that the wind could conceivably get under, pick up and pull off,” Norton said. “We actually have two types of solar panels on our roofs. On the upper roof, which was not reinforced, the panels lie flat because of the concern of wind. On the lower roof, they are at a 10-degree angle. We could support them and secure them to the roof differently.”

Both of these factors were primarily issues for the new connector roof.

“It was designed just for snow load, so we had to deal with five-pounds per square foot of additional loading factor which also had to take the weight of the panels and the wind shear factor into account,” Norton said.

The greenroof surrounds the solar array. It starts approximately a foot from the edge of the roof and covers another nine to ten feet to the perimeter of the array.

Bordered on the outer edge by blocks and perforated edging, the soil is two to three inches deep. It is blanketed with cuttings of drought-resistant succulents. The bed is then covered with a water-permeable and bio-degradable fabric similar to burlap, which keeps the cuttings in place as they establish themselves.

“They will grow to be between three and four inches tall. We do not want to block off the solar panels,” Norton said.

The greenroof system is patented by Philadelphia, Pennsylvania-based Roofscapes, which franchises it to local landscape companies, which do the installation. For the WGBH project, Apex Green Roofs did the work and will maintain it for two years as the greenroof gets established.

“These succulent plants are very low maintenance. They don’t require a lot of irrigation. The plants are very hardy in the summer. It’s more like a wild field,” Norton said. “We actually do not have irrigation up there for them. You hate to pour water on a roof if you don’t have to.”

Installed in May, the cuttings are taking hold and are expected to turn greener through the fall months. Architects wanted to make sure that the view of the roof was accessible for employees as well as visitors.

“The roof is right out from our cafeteria and everybody can see it when they go for lunch,” Pullman said.

Long Term Benefits
WGBH was not able to gain any LEED credits for its solar array because it generates less than one-percent of the broadcaster’s total power needs, which are huge considering the electricity demanded for its studios and offices. The system can produce up to 100kw per day, while the facility’s 24/7 demand is 973kw. The array needed to generate a larger percentage of the demand to be included in the LEED certification.

“In our case, the solar array serves a small percentage of our need, but it’s just that much more energy we won’t have to buy off the grid,” Pullman said. Meanwhile, the station will benefit from locked-in rates with its power company because of the solar system.

As for the greenroof, there are a host of benefits. It will produce a substantial savings in heating and cooling costs over the course of a year while collecting 70 to 80 percent of stormwater runoff. What rainwater does make it off the roof will travel to a buried retention tank, which can hold up to an inch of rainwater runoff to be slowly released into the soil.

“Everybody is really proud of the building. It’s working well for us,” Pullman said. The plans are to expand the greenroof in the future, as funding sources are identified. The project was made possible through funding from the sale of WGBH’s property to Harvard, and a successful capital campaign. No state or federal tax money was involved.

“We hope to find individual or institutional grants that are available to support new green features,” Pullman said. “Going forward, we’ll be open to getting more green features into the building.” SLDT