Designing the PerformanHceigh- Classroom
By G.Z. Brown, Dylan Chavez and Terry Blomquist
The high-performance classroom project began as a
research initiative funded by
the Northwest Energy Efficiency Alliance and the University of Oregon. The goal
was to create an energy-efficient design for
a K- 12 classroom, at lower first cost than
that of typical classrooms. We were willing to challenge common assumptions
about energy efficiency and cost.
Aspects of the high-performance classroom design have been successfully used
in several projects here in Oregon, notably
the Mt. Angel Theological Studies Building in Mt. Angel, the Da Vinci Arts Middle School in Portland and Canby High School in Canby.
For a typical classroom, up to 28 percent of the construction cost
is for systems, with the remaining cost covering the envelope and
structure. If we can reduce the loads on those systems to zero or
near-zero, then no systems are needed and no energy is used. And we
save much of the cost of buying and installing the systems.
Energy-efficient design has traditionally been evaluated by look-
Basic Principles of the
1. Use high insulation values and a tight enve-
lope to reduce system load.
2. Use daylighting and passive thermal strategies
to reduce system use.
3. Downscale systems to reduce first cost. Use
simpler systems where appropriate.
4. Be flexible about schedules for building use,
to improve energy efficiency.
ing for an “optimization point,” typically R19 for wall insulation and R30 for the
roof. Beyond that level, the cost of further
efficiency typically results in minimal
increases in energy savings. Our approach
goes further: We calculated that at R30 for
walls and R60 for the roof, we could eliminate mechanical heating and cooling
systems. While the additional insulation
is expensive, the elimination of mechanical systems and their long-term operating
costs more than paid for it. In place of
mechanical systems, we use climate as a
resource rather than a liability.
Daylighting: Since most classrooms
are used during the day, we rely on daylighting for illumination,
thus saving the cost and load of electric lights during daylight hours.
After reviewing data from central and northern European countries,
the Illumination Engineers Society (IES) and the Collaborative for
High-Performance Schools (CHPS), we arrived at a minimum target
illumination of 20 foot candles, which is below the 30-100 f.c. recommended by the IES but within the 19-100 f.c. range of international
Canby High School
The high school got a 10,000-square-foot addition, completed in
March, including four classrooms and a large multiuse area. The
budget was part of a $3.8 million restoration of the entire building, so
cost per square foot can’t be calculated. The site is at sea level, about
10 miles south of Portland, Ore.
The new classrooms serve a set of unconventional programs, so a
key design goal was to achieve a flexible environment. Architect Heinz
Rudolf of BOORA Architects made use of glass internal walls. Bus traffic passes close to two sides of the building, so operable side windows
are set high for sky views only. Most of the light comes from large
south-sloping skylights with light-control louvers set between two
polycarbonate panes. Louvers can be set manually or automatically
with stepper motors buried in the ceiling structure for silent operation.
BOORA ARCHI TEC TS