Buildings
Mission Accomplished at Winrock International's Global Headquarters
(greensource.construction.com - 06/2006)
By Nadav
Malin
Overlooking the Arkansas River in suburban
Little Rock, Winrock International’s new headquarters
is “an abstraction of the traditional Arkansas dogtrot,”
according to design architect Kenneth Drucker, of HOK. Its
signature feature, a gull-wing roof, not only keeps the sun
at bay, it collects rainwater—an integrated solution
that resulted from a collaborative and tightly managed design
and construction process.
Winrock International is a nonprofit
organization that supports sustainable development. In a staff
of around 700 all over the world, about 70 employees are based
at Winrock’s headquarters in Arkansas, which was, until
recently, on Petit Jean Mountain in rural Morrilton. That
campus was expensive to maintain and required a lot of staff
travel, so the board decided to find an alternative use for
that facility and move its headquarters to Little Rock.
Given the organization’s mission,
making its new building green was a given. Winrock’s
president, Frank Tugwell, was familiar with green building,
having worked previously on a project with green architect
William McDonough. Winrock’s board established two key
goals for the project: that it would achieve a LEED Silver
rating and that it would do that without costing any more
than a comparable conventional building in Little Rock. The
board set the budgetary constraint not only because of the
organization’s tight funds, but because they were determined
to set an example for the local real estate market. “We
wanted to be able to tell people who come in and are impressed,
that it is something they can afford,” says Tugwell.
Before hiring an architect, Winrock contracted
with Horne Rose, one of several companies affiliated with
green developer Jonathan Rose, to serve as the owner’s
representative. Horne Rose staff facilitated the process of
selecting the design and construction team, then managed design
and construction. Sarah Haga, of Horne Rose, contends that
conditions established at the inception of a project, such
as how decisions will be made and what the schedule will be,
can affect the outcome dramatically: “Our experience
is that the best, most sustainable projects have a very thoughtful
schedule that allows time to integrate green components,”
says Haga.
By showing examples of their previous
work, principal-in-charge Bill Odell and his team from HOK
convinced the board that they could produce a high-performance
green building on a conventional budget. As soon as the architect
and contractor had been selected, all the consultants participated
with the client in a design charrette to develop the concept
design.
The 2.2-acre site was tightly constrained
by setbacks and other factors, leaving limited options for
siting the building. There was only one way to orient the
building in the available space, and it had the long axis
running north-south. “We were not very happy when we
saw the site,” admits Odell.
After working through a series of shading
studies, the team’s solution to the less-than-optimal
orientation was an oversize roof, which shades the building
through most of its occupied hours. Some large trees were
preserved nearby, helping to shade the building when the sun
is low in the sky. The narrow plan that was dictated by the
site’s constraints helps with daylighting, nearly all
of the regularly occupied spaces are fully lit during the
day, so the lights don’t need to be on.
Having the construction manager on board
during design worked well. “We were able to run budgets
on a number of design options through the course of design,”
says Stan Hobbs, AIA, of Nabholz Construction. “The whole
experience was great for us,” he adds, noting that it
isn’t always so smooth. Designers sometimes think “we’re
going to be telling them how to design the building,”
he says; on the contrary, Hobbs’s goal is to help them
figure out how to get their own design built.
Throughout the design process, solutions
were proposed and then adjusted to meet budgetary constraints,
which involved frequent negotiations between the contractor,
the owner’s rep, and the architects. “At first the
entire building was glass,” recalls Tugwell. When that
turned out to be too expensive, some of the glazing was replaced
by opaque siding. Nabholz was also helpful in figuring out
simpler ways to achieve the desired ends, which, Haga notes,
saved energy during construction: “Constructability is
looked at as a cost-saving measure, but it’s also a sustainability
measure.”
Little Rock had little if any recycling infrastructure, so reaching
the 50 percent recycling goal needed for achieving a LEED point
seemed unlikely.
The project’s mechanical engineers were willing to explore
unconventional approaches for providing comfort in a modern
office building, but only up to a point. The entire office
space has raised floors with under-floor air distribution,
including a separate diffuser for each workstation so each
occupant has control over temperature and airflow. But natural
ventilation was not adopted, nor was the idea of taking advantage
of the adjacent marina to use a water-source heat pump instead
of a conventional cooling tower.
Although Nabholz Construction had not worked on a green building
before, it took on the task with gusto. The firm sent several
people, including the on-site supervisor for the Winrock project,
to the U.S. Green Building Council’s Greenbuild conference
in Austin, Tex in 2002. Odell ran into two of them and was
amazed at their enthusiasm. “They were working that expo.
Not just picking up literature, but o the subcontractors.
Prior to Winrock’s construction, Little Rock had little
if any recycling infrastructure, so reaching the 50 percent
recycling goal needed for achieving a LEED point seemed unlikely.
But Nabholz staff catalyzed the creation of a local recycling
infrastructure and achieved a recycling rate of 75 percent,
which is worth two points in LEED, at no added cost. “That’s
something that we now do on all of our projects, whether they
are pursuing LEED or not,” reports Hobbs.
Winrock’s new headquarters has generated a lot of excitement
in the community. Together with two other LEED buildings,
the Clinton Presidential Library and the headquarters for
Heifer Project International, this project has put Little
Rock on the map as a green building tour destination. Tugwell
and others frequently find themselves giving impromptu tours
to visitors.
An extended process of shakedown and adjustments has followed
initial occupancy, so the Winrock staff has yet to begin documenting
energy performance. Among the significant changes was replacing
the cooling tower with a heat-exchange coil in the marina.
Fortunately, selling the cooling tower offset part of the
cost of this modification. Additionally, lighting controls
that were set up incorrectly are being rewired.
In the end, the most important test of a facility is whether
the occupants like it. In this case, says Tugwell, there is
no doubt that they do. “I think that they stay at work
longer,” he says. “They hang around because it is
a pleasant place.”
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