Roofing: Strategic Advantages of Green Roofs on Campus
now, many American educational campuses have had their first
green roof installed. The ability of a green roof to reduce
high summer rooftop temperatures, absorb rain storm water
and to improve the life cycle of the waterproof roofing
itself has convinced institutions to accept a change to the
sort of low-slope roofs that they had installed for decades.
While most American facility administrators are becoming
familiar with the basic issues regarding this emerging
technology, there are a series of strategic advantages for
educational institutions associated with green roofs that
deserve some discussion.
Green Roofing adds valuable green space and is both
functional and enjoyable.
Conceal Parking For many educational institutions, the need
for ample parking results in vast expanses of asphalt
surface lots and concrete parking structures. While the cost
of installing underground parking is significant, a
ground-level green “roof” can add valuable green space that
beautifies a campus. Instead of parking lots and ramps
pockmarking the campus landscape, the greening of a campus
through underground parking with lawns and gathering spaces
on top provides a more picture-postcard campus experience
that can be treasured by students and alumni alike.
At the University of Wisconsin-Madison Education Building, a
surface parking lot lay between the facility and Lake
Mendota, ruining the view. Even worse, a major campus
pedestrian path also leads students to walk right through
the parking lot to enter the building on the lake side.
During a recent renovation and expansion, the parking area
was lowered and covered with a green roof and plaza. The
major campus path now crosses this landscaped plaza, and the
Education Building appreciates a vista of Lake Mendota
without an unsightly surface lot in view.
Green Roofs Become Valuable Recreational Open Spaces
As many American campuses continue to build out their
remaining open space, they are finding themselves landlocked
by neighborhoods with a shortage of high-quality outdoor,
open campus spaces for students, staff and faculty. Green
roofs on buildings offer an opportunity for new construction
and recreational open space to co-exist.
Planning for Discovery World at Pier Wisconsin—a water
resources education and science center on Milwaukee’s
lakefront—was challenged with siting a 200,000 square foot
facility in a politically sensitive location. A “tip of the
iceberg” approach was the solution. Several large aquariums,
water education facilities, a catering kitchen, loading
docks and a 200-car garage were all placed underground. On
the roof of the underground construction an open lawn was
designed, which looks like part of the adjacent lakeside
park. Today, families enjoy picnics, children play Frisbee,
and students study on the broad expanse of green—never
knowing they are on a green roof.
Green Roofs Ease Approvals
Building Discovery World on Lake Michigan was controversial
and would not have occurred without deploying a green roof
as a critical strategy to construct and conceal a large
expanse of square footage and parking. The green roof
allowed the project to receive the community support it
needed to go ahead.
Similarly, the plan for Cambridge Commons, an off-campus,
undergraduate residence hall for the University of
Wisconsin- Milwaukee, initially encountered resistance from
the Milwaukee River Work Group. The environmental group was
opposed to having the hall built on the hilltop site
overlooking the Milwaukee River. The solution
was a LEED (Leadership in Energy and Environmental Design)
Gold building on the former urban brownfield, with green
roofs on the north and south wings. Native plantings on the
roofs absorb rainfall that would otherwise run off into the
river. The project’s highest roof also channels rainwater
into an underground, 20,000-gallon storm-water tank, where
stored water is slowly released to irrigate plantings around
The key to community approval was a LEED building with green
roofs; once the Milwaukee River Work Group enthusiastically
endorsed the project, the city alderman voted for its
Green Roofs Contribute to LEED Certification
If higher education campuses are sandwiched between the
neighborhoods around them, frayed relationships can become
contentious when a college or university needs to expand
into an adjacent neighborhood. Successful institutions work
with neighborhood groups to get their support and acceptance
for new construction before zoning changes and political
approvals are needed.
Because a large percentage of grassroots community
organizations are highly interested in green buildings and
LEEDcertified structures, they often object to traditional
construction but are willing to support sustainable
architecture. Green roofs can be a key element in such an
approval process, as they are a visible symbol of a
community or institution’s commitment to green design and
development. They also contribute points to LEED
Educational institutions across the country are, in fact,
adopting LEED guidelines to demonstrate their commitment to
sustainability. Green roofs contribute points related to
mitigation of the “heat island” effect and storm water
retention. The increased roofing insulation value that green
roofs provide reduces energy usage, which adds more LEED
Green roofs were an integral part of the overall
sustainable-design strategy that resulted in LEED Platinum
certification for the renovated and expanded Education
Building at the University of Wisconsin-Madison. Underground
parking was concealed with plazas and green spaces, and a
third floor roof over an atrium became a green roof with a
deck for students and faculty to lunch and meet outdoors.
Green Roofs Help Restore Lost Natural Habitats
Additional LEED points are possible through innovation in
increasing the biodiversity of roof gardens and plantings.
Research into such possibilities is critical, because on
most education campuses today, every last vestige of the
native ecosystems that once stretched across a site—whether
prairie or meadow, woods or wetland—have been replaced with
buildings, parking lots and high-maintenance lawns.
Intensive green roofs on new buildings, with soil deep
enough for carefully selected native species, offer the
opportunity to restore at least a part of such lost flora.
On-campus expertise provided by students and faculty from
the biology or landscape architecture departments could
result in a rooftop biodiversity showpiece unique to the
Green Roofs: Environmental Education and Research
Green roofs are a growing field of research and development,
with new information on technological approaches to
installing and sustaining diverse plant communities
occurring annually. Colleges and universities could become
part of this effort, partnering with industry to conduct
in-depth research into technical assemblies, maintenance,
plant materials and ecosystems appropriate to specific
regions, temperature mitigation, storm runoff data, and many
other areas pertaining to green roof development. An
on-campus green roof project is an excellent forum for
educating students in a developing technology and involving
them in related research efforts.
The Zoological Society of Milwaukee’s Conservation Education
Center has a roof covered with sedums. During heavy
rainfall, the plants soak up excess runoff. Sensors embedded
in the roof provide researchers with a data stream comparing
the roof’s temperature with that of a conventional roof.
Typical data from a hot summer day indicates the center’s
roof is cooler than the traditional roof, and cooler than
the ambient air temperature. As a case study, the center’s
green roof provides an excellent example for other
Green Roofs: Zero Storm Water Discharge Zone
Storm water remains a significant problem for many campuses.
Traditional roofs are impervious surfaces and shed all
rainwater to grade or into storm sewers, where a rapid
influx of water and debris can contribute to flooding and
sewage discharge problems, which plague many communities.
Green roofs hold rainwater in place, allowing it to be
absorbed into the soil, used by plants and evaporated in the
atmosphere over time. Green roofs can contribute
substantially to storm water control on a campus.
The University of Wisconsin-Milwaukee campus is pursuing the
goal of becoming a zero storm water discharge zone, using
rain gardens, storm-water retention ponds and green roofs.
The green roof on Cambridge Commons, for example, was
designed to control storm water and improve the water
quality of the river below the building. These initiatives
also contributed to the project achieving LEED Gold
Educational campuses are increasingly being asked to control
the runoff their buildings and other impervious surfaces
generate. Green roofs are a key component of transforming
campuses into zero storm water discharge zones. At that
point, the open space, LEED points, research and development
opportunities, biodiversity and native habitat that green
roofs also provide become an integral part of a
comprehensive system for campus sustainability.
James Shields, FAIA, is a design principal in the
Milwaukee office of HGA Architects and Engineers, and an
Associate Professor of Architecture at the University of