Fins, eaves, curbs, skylights and panels aid this facility's
By Mark Robins, Senior Editor
In the arid southwest, it is critical to reduce and reuse water
in every possible manner to protect groundwater supplies. Tucson,
Ariz., is located in the Sonoran Desert, a place rich with unique
plant and animal species and a high quality of life, but with few
natural water resources. It receives 12 inches or less of rainfall
In its new Eastside Water Facility office, the city of Tucson
has incorporated water harvesting, and passive heating and cooling
features to attain green goals. Metal is a contributing factor in
this three-building project's success.
Standing seam aids green
This self-contained satellite facility for 75 employees contains
offices and a shop area, fully stocked warehouse and an outdoor
storage yard. The center sits on a 25-acre site and the
construction design left almost 8 acres of natural, undisturbed
open space set aside.
A standing seam metal roof with a single-slope design containing
a high amount of recycled content from Star Building Systems,
Oklahoma City, and Battenlok HS Snow White roof panels from MBCI,
Houston, has proven pivotal to the building's environmental
efforts. Steadfast Structures, Tucson, is the authorized Star
Builder who brought the project to Star and played a key role in
pricing the project, and in clarification so the order could be
written for engineering and drafting to design and detail the
"The primary structural material is made up of the structural
frames produced by the EAF (electric arc furnace) process which has
a high rate of recycled material," says Franz Mutis, PE, LEED AP
BD+C, manager of engineering services at Star Building Systems.
"The engineers at Star used a tapered section for the primary
structural design. The tapered section allows for the most
economical and structurally adequate design while maintaining the
least weight design."
This type of metal roof was chosen for its long durability,
which factors into a low lifetime cost. It is also virtually
maintenance free, has a superior warranty and a wide array of cool
roof colors that are highly reflective for lower cooling costs. The
metal can expand and contract with the outside temperature and the
roof can support two photovoltaic offerings that may be applied at
anytime in the future.
In addition to these benefits, this standing seam metal roof's
single slope allows for a simplified design and efficient rainfall
routing into 12 water harvesting cistern tanks from Southern
Arizona Water and Rain Harvesting, Tucson. Their total water
capacity storage is 40,176 gallons. Based on average historical
rainfall data the potential annual rainwater yield from the
facility's roof surfaces is 157,648 gallons.
These galvanized steel tanks also double as passive shade for
the buildings' south side. They are visible from both major
roadways and promote a new community aesthetic. Metal roof panels
significantly reduce incidental particulate contamination of the
tank water, which can occur over time with other roofing
"Metal panels are ideal system to collect the water," says
Mutis. "Certain types of roofing can't do that. For instance,
asphalt shingles can't, because the water gets contaminated."
Furthermore, the single-slope roof design aids in water
harvesting efficiency since only one side of the building requires
the water tanks. The water is collected from the rain running off
the roof into the gutters flowing into the harvesting tanks from
the downspouts. The rainwater is filtered as it enters the tank. It
is kept dark and oxygenated to discourage algal growth. The tanks'
calming inlets ensure that any sediment at the bottom of the tank
does not get stirred up. This is not drinking water, but can be
used for flushing toilets, washing clothes and garden watering.
Rainwater harvesting helps earn points in the water efficiency
category for LEED. "Real time" irrigation controllers gather daily
weather data and adjust watering schedules, which help rescue
demand for the irrigation system. Also, pervious concrete ramps at
the warehouse shed water into landscaping, rather than adding to
Heating and cooling
The buildings' single-slope high side faces the north to reduce
desert sun exposure. To achieve green goals and increase energy
savings, standing seam roof panels are compatible with different
types of insulation. R38 insulation, from Therm-All Insulation
Inc., North Olmsted, Ohio, lowers the energy required to heat and
cool the facility. It increases the R-value in the roof and walls,
and reduces the heat transfer through them, maintaining the
temperature with less fluctuation.
The reduced energy use was determined prior to construction with
an energy model. Energy conservation is reflected in the Energy and
Atmosphere credits for LEED.
The facility's steel shade fins from Star Building Systems
deflect direct sunlight away from windows, allowing for natural
lighting, which contributes to the daylighting credits available
through LEED. Because the high side of the building faces north,
the east-west sun hits the sides of the shade fins.
Below eave canopies from Star supplement the shade fins. "They
allow for strategic placement of the building's fenestrations to
maximize the natural light provided by the sun, which goes toward
earning daylighting credits," says Mutis. "The canopies also
deflect the sun's rays, which heat the building, in turn lowering
the energy requirement for the building and increasing the energy
efficiency of the structure."
Seventy-five percent of the buildings' interior spaces receive
daylight from skylights from Daylighting Systems Inc., Glendale,
Ariz., and exterior clearstory windows from Geronimo Ltd., Tucson.
These increase daylight, which reduces both artificial lighting and
the energy demand.
Weathertight curbs from R & S Manufacturing and Sales Co.
Inc., Newbury Park, Calif., position these skylights on the roof's
low slope where roof penetrations are typically not recommended.
The skylights attach to the curb, which is attached to the roof
panels with materials provided by the manufacturer.
Tucson Water and its project contractors worked with nearby
residents and businesses throughout the various phases of the
entire design and construction to achieve as best a fit as possible
into the natural surroundings of area. The green/low impact
development was such a success three more satellite facilities are
Eastside Water Facility office, Tucson, Ariz.
Architect: Albanese-Brooks Associates, Tucson
Authorized builder: Steadfast Structures, Tucson
General contractor: Lang Wyatt Construction, Tucson
Landscape architect: ARC Studios, Tucson
LEED consultant: Architectural Fusion, Tucson
Clearstory windows: Geronimo Ltd., Tucson, www.geronimoglass.com,
Insulation: Therm-All Insulation Inc., North Olmsted, Ohio, www.therm-all.com, Circle
Metal building system, shade fins: Star Building Systems,
Oklahoma City, www.starbuildings.com,
Metal curbs: R & S Manufacturing and Sales, Newbury Park,
Metal roof panels: MBCI, Houston, www.mbci.com, Circle #49
Skylights: Daylighting Systems Inc., Glendale, Ariz., www.daylighting.com, Circle
Water harvesting tanks: Southern Arizona Water and Rain
Harvesting, Tucson, www.southernarizonaraingutters.com,