Healthcare Design - December 2015 - 35

JONATHAN HILLYER PHOTOGRAPHY

(Orlando, Fla.). "We had a vision of the experience
we wanted to create and did the research on
product development, installation, and ongoing
maintenance to select plant life and designed
around what those plants needed to survive."
Sharing a few lessons learned, Cluff says that
several of the trees specified were taller than the
design parameters of the lightning protection
system, so they ultimately had to be replaced
with shorter trees. Another misstep was failing to
install sun shading over some artificial turf that was
placed under a multistory curtainwall system. The
consequence was some of the turf melting from the
glare. "Add sun shading to any adjacent curtainwall
system," Cluff cautions.
One other challenging aspect of the Nemours
green roof project was the fact that the authority
having jurisdiction restricted reclaimed water from
entering any facility, so it was an arduous public
works process to bring reclaimed water to the roof
gardens for irrigation and to meet the intended
LEED credit.
Heads to tails
It's important for healthcare providers to understand that rooftop gardens require regular maintenance with defined protocols and a functioning
irrigation system.
Uhlmann says she often finds that internal maintenance staffs fail to adequately water and weed
the roof. She's also seen a hesitance on the part of
healthcare organizations to hire green roof professionals skilled in this type of maintenance. "While
not always a welcome addition to what are typically
lean operational budgets, regular, well-performed
maintenance is far less expensive than the cost to
renovate and restore a vegetated green roof," she
says.
At the same time, some well-considered design
selections can help lower maintenance requirements, says Andrew Quirk, senior vice president
of the healthcare center of excellence at Skanska
(Nashville). For starters, proper vegetation for the
climate-for example, drought-resistant native
material in California-is the first course of action.
"Also, tray system installations can help make the
maintenance process easier because the system
comes complete as a prefabricated element,
including the drainage material, soil, and plants." As
opposed to a regular garden in soil, the tray works
much more effectively to drain and filter the water
as it enters the soil.
Providers must also determine if the roof will be
accessible as a space where patients, families, and
staff can find respite, or if it will be what's called

an extensive rooftop that's for viewing only. While
accessible roofs more fully tap into the healing and
biophilic benefits of providing access to nature,
they do come with larger structural requirements and capital costs. "The best way to make
a selection is to balance first cost versus whole
life cost in order to achieve a desirable return on
investment [ROI]," Quirk says. "The second way to
address cost is to verify expectations for the green
roof. What does a facility want the roof to do? For
example: reduce operating costs, conserve and
manage resources, or serve as a healing garden
for staff and patients?"
Overall, Jeffrey Keilman, senior associate at
Perkins+Will (Boston), says that the decision over
which roofing system to select relates to aesthetics regarding planting choices, required maintenance, and even upfront costs with structure
and waterproofing considerations. In particular,
waterproofing relates to reliability and warranty, so
it's vital to select the correct roofing/waterproofing system, as access is usually limited once the
green roof is installed. "In my experience, one
system [accessible versus inaccessible] is not
more common than another," he says. "This is due
to each project having its own particular goals and
constraints."
Although costs will vary significantly for new
construction, Quirk offers a general rule of thumb
of $30 to $40 per square foot for an extensive roof
and $50 to $100 per square foot for an intensive,
or accessible, roof. To help owners best calculate
ROI, it's important to take into account gains from
reduced heating, cooling, and maintenance costs.
For example, a U.S. General Services Administration "Green Roof Benefits and Challenges" study
documented $14.10 per square foot of green roof
savings from reduced infrastructure improvements
and fees, and $6.60 per square foot of savings
from decreased cooling and heating energy expenses for a 5,000-square-foot green roof.

Altogether, 33 acres of
green roof, designed by
Skanska, with creeping vines,
sprawling glass, planted pots,
and water features create a
vibrant, colorful setting for
patients, family, and staff at
Nemours Children's Hospital
Orlando.

HCDmagazine.com 12.15

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Healthcare Design - December 2015

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