Page 206 - The Green Building Bottom Line The Real Cost of Sustainable Building

184 CHAPTER 6

fan motor and CO sensors were installed, and electronic fresh air dampers were
2
added. The largest investment was rebuilding the chiller, a project that needed to be
done on weekends to avoid a negative impact on our tenant partners. The chiller
rebuild totaled $15,420. The new fan motor, CO sensors, and fresh air dampers were
2
an additional $5,147.
The building’s heating and air conditioning system was retrocommissioned—a sep-
arate process done by a commissioning agent that guarantees a system operates as the
manufacturer specified—at a cost of $7,128. Although it’s not possible to directly cal-
culate if retrocommissioning has saved money, we do know that maintaining the sys-
tem properly helps it work more efficiently and affords better control of air flows,
increasing tenant comfort and reducing complaints.

WATER EFFICIENCY
All the restrooms were retrofitted with low-flow toilets (1.6 gallons per flush), touch-
less faucets with aerators, and (in men’s restrooms) waterless urinals in 2005. Break
room sinks have faucets with low-flow aerators. Water use dropped by over 20 percent
after we upgraded the restroom fixtures in the building (by changing the toilets and
urinals) and made changes to the landscaping that reduced the need for outdoor irri-
gation. Per-day water usage dropped from an average of nearly 3,000 gallons per day
to 1,600 gallons per day in 2007, a reduction of almost 50 percent. Dollar savings during
that same six-year period ranged from $240 to over $4,700 per year. (See Table 6.4.)
That drop in consumption is in part due to the installation of the reduced-flow faucets
with aerators in the restrooms and break rooms. Also, because of Georgia’s continuing
rainfall deficits and drought, we made changes to our landscaping plans to reduce
annual plantings and reduce water used for irrigation. In the summer of 2007, when
the ban on outdoor watering was enacted, we stopped all landscape irrigation, which
further reduced our annual water usage.
The building contains six sets of restrooms (one set per floor, plus men’s and women’s
facilities in the fitness room). The public restrooms were original to the building and
in need of updating. The restrooms were fully deconstructed, floor tiles and counter-
tops were recycled, mirrors and partitions were reused, and new floor and wall tiles
and countertops were installed. Plumbing improvements were a portion of the reno-
vation project and totaled $20,567 of the $100,000 spent for restroom renovations.
Water rates increased by only a moderate 7 percent annually from the base year to
2007, with savings of $10,985 during the sample period. For our accounting purposes,
the payback is calculated from the period it was expensed, indicating an average sav-
ings of $1,465 per year and a payback of fourteen years. Water usage and savings can
be seen in Table 6.4.
We do still use paper towels for hand drying in restrooms. Because of the location
of the restrooms, electric hand dryers are simply too noisy, and their operation would
result in sound transference to adjacent offices. The paper towels and toilet tissue we
use are 100 percent recycled content, of which 30 percent is post-consumer.