Green on the inside
GSA uses 3-D, 4-D modeling and automated systems to improve buildings' energy efficiency
THE GENERAL Services Administration is
the country's largest landlord. It manages
more than 300 million square feet of space
in 8,600 buildings owned or leased by the
government. It is also one of the most efficient
landlords: Its cost to operate those
buildings is 9 percent less on average than
that of the private sector.
GSA began focusing on energy efficiency
about 30 years ago. Since 1985, it has reduced
energy use by 30 percent per square
foot and the government's energy bill by
about $60 million a year, said Kevin Kampschroer,
director of GSA's Office of Federal
High-Performance Green Buildings.
Information technology is playing an increasingly
big role in conservation efforts,
as both a target and a tool, he said. IT typically
makes up the largest portion of a
building's energy use and therefore represents
a significant potential for savings. Replacing
CRT monitors with more efficient
flat screens can shave off as much as 3 percent
of an office's energy use, he said.
Officials are also using computer technology
in the design and operation of buildings
to increase their efficiency.
'There is a significant improvement in the
quality of the information' being used in
building design, Kampschroer said. 'We're
looking for more information on how the
building will perform earlier in the process.'
To that end, in fiscal 2007, GSA began requiring
the use of Building Information
Modeling in the planning process for all
buildings. BIM covers a range of computer-aided
design technologies, including 3-D
and 4-D computer modeling of construction
projects. Time, the fourth dimension,
represents the phases of a project. That additional
information allows more detailed
planning and better estimates of how a
building will function.
'Critical to successful integration of computer
models into project coordination,
simulation and organization is the inclusion
of information to generate feedback,'
GSA's program materials state. 'As a shared
knowledge resource, BIM can serve as a reliable
basis for decision-making and reduce
the need for re-gathering or reformatting
information.'
BIM technology can also analyze energy performance to monitor and improve
operational efficiency during the lifetime
of a building.
Before BIM, engineers had only broad
sets of data that related to a building's
core or periphery, said Charles Matta, director
of GSA's Center for Federal Buildings
and Modernization. Now, they have
access to detailed datasets on all components
of a building, which they can use
to create multidimensional models.
Before the 2007 BIM mandate, officials
used the technology in nine pilot
projects involving new construction,
seismic retrofitting of existing buildings,
and renovation of historic buildings
in Washington; New York; Los Angeles;
Houston; El Paso, Texas;
Portland, Ore.; and at the U.S./Canadian
border. They are now using it in
more than 35 projects.
Furthermore, IT is a component of
automated systems that operate a
building's lighting, heating, ventilation,
air conditioning and other physical systems.
Sensors monitor conditions and,
by observing occupancy and behavior,
determine optimal conditions so energy
is not wasted. Sensors and individually
controlled light ballasts can reduce the
cost of lighting an office by as much as
30 percent, and systems that monitor
occupancy and adjust lighting and air
conditioning can reduce costs by another
3 percent, Kampschroer said.
Effectively controlling lighting is a primary
way to save energy. Most buildings
were designed without computer
monitors in mind, and lighting levels
are often unnecessarily high, Kampschroer
said. Sensors and controls that
keep lighting at appropriate levels offer
considerable savings.
A technology that is showing great
promise is advanced metering, which
GSA is adopting in a handful of major
cities to monitor electricity use in buildings.
Administrators can view the resulting
data via the Web to gauge how
adjustments are affecting energy consumption. It is a necessary tool in cities in
which the government pays a lower rate for
electricity if it agrees to curtail energy use
during periods of peak demand.
About 60 government buildings in Washington,
D.C.; 67 in Texas; and a handful in
New York City use advanced metering. In
summer 2007, Washington avoided several
brownouts by being able to reduce energy
consumption on exceptionally hot days,
Kampschroer said, adding that GSA officials
want all major government buildings
to use the system by 2012.
When it comes to retrofitting buildings to
increase energy efficiency, the job is easier
with structures built before 1940, Matta
said. 'They have better efficiency than buildings
that were built decades later,' he said.
'Availability of energy was limited when
these historic buildings were built,' said Martin
Weiland, a senior mechanical engineer at
GSA. They were designed to make the best
use of the energy available. Windows were
used for light and ventilation, and smaller
zones within the building took advantage of
those features. Massive walls helped stabilize
temperatures.
By the 1950s, when air conditioning and
steel frame construction became common,
designs changed. Large floor areas and
windows fused shut became the norm.
'These are much more energy-intensive facilities,'
Weiland said.
Nevertheless, automated tools for monitoring
and adjusting building controls are
still maturing, he added. Systems are often
more sophisticated than users can handle,
which means that much of the capability
goes to waste.
'There is a real need for a crossover field'
of IT developers and programmers who understand
buildings' mechanical and lighting
systems, Weiland said.
In other respects, the technology is not sophisticated
enough. 'We still have a lot of
problems with interoperability,' Kampschroer
said. 'We're not at the point where
you can go out and get a comprehensive
building control system. We are still working
with multiple control systems.'