ESD design guide for Australian Government buildings: Edition 2

esd opportunities in building
OPPORTUNITY 9
water conservation
Government Buildings – Possible
Water Savings
‘The potential savings available from
Australian Government buildings
and operations are between 4,296
and 7,405 ML/year. This is based
on savings assumptions by building
type developed through the desktop
study and site assessments.
Achieving these savings would cost
between $8.2 and $14.6 million
based on cost assumptions derived
from empirical case studies in the
literature.’ 43
Figure 39: Water reduction methods 42 , ISF.
A dual flush toilet replacing a
single flush unit in an office
building will save approximately
360 litres each working day (90
kL per year) in a female toilet,
an annual financial saving from
potable water alone of about $90
or more. For a male toilet the
saving will be about 40kL/year.
For the Edmund Barton building,
with approximately 2,800 staff, this
would mean an annual saving of
more than 9 ML, or $11,000 for a
A recent study by the Institute for
Sustainable Futures showed that an
80% reduction of potable water and
90% of sewage was possible in a
commercial building
Opportunities for water reduction are
as follows (these are discussed in
greater detail below):
• management and monitoring,
• leak avoidance,
• efficient fixtures and fittings,
• water sensitive landscaping and
• source substitution.
Figure 40: Water image, stock.XCHNG.
Efficient fixtures and fittings
Water efficiency labels are being
Management and monitoring
Regular monitoring of meters
and sub-meters, either manually
or by connection to the Building
introduced for many water-using
appliances. Specification of efficient
fixtures and fittings (as noted below)
can reduce water wastage.
Management System. This is
particularly useful in establishing
base flow rates and then identifying
leaks when water use exceeds normal
variability ranges.
Toilets and urinals
• Toilet and urinal adjustment
– adjust floater to use minimal
water
• 3/ 4.5L dual flush toilets
Leak avoidance
• Urinal flush controls – sensors
• Report of leaks to building
management - building occupants
should be made aware of where
and to whom they can report any
leaks. It is important to promptly fix
any reported leakages for positive
feedback.
• Waterless Urinals
Showers
• Flow regulators – need good advice
on type as some may result in an
inadequate shower
• AAA or AAAA showerheads – made
• Regular inspections of toilets,
urinals, taps and showers.
to increase pressure so as to still
have a good shower
Taps
• Flow restrictors for taps and tap
aerators
of under four years.’
• Automatic cut-off and sensor
‘In a busy public building, the
saving from a dual flush toilet
operated taps
retrofit could be more than 1 kL per
day per toilet, or about 400 kL/year
for a building open every day of
the year. The cost of retrofitting
dual flush toilets depends upon
the plumbing changes and
redecorating that would be
required. It can range from $250 to
41 Berry T., Edgerton N., Milne G., Jha M. and White
S. (2004) Feasibility Study for a Policy on Water in
Government Operations, ISF, Sydney, July 2004.)
p. 41-42.
42 Chanan, V., White, S., Jha, M., & Howe, C. 2003,
‘Sustainable Water Management in Commercial
Office Buildings’ Innovations in Water: Ozwater
Convention & Exhibition, Perth, 6-10 April 2003.
43 Berry T., Edgerton N., Milne G., Jha, M. and White
S. 2004, Feasibility Study for a Policy on Water in
Government Operations, ISF, Sydney, July 2004.)
ESD DESIGN GUIDE FOR AUSTRALIAN GOVERNMENT BUILDINGS 031