Water remains my favorite and most important issue when addressing green building
concerns. It is certainly not the most important topic when looking at the
various certification checklists, like the USGBC LEED rating system. It finally
received a prerequisite in the last update, but is dwarfed in the overall point
scale by considerations for energy and materials.
Energy indeed has gotten a lot of attention in the last few months, especially the
concept of net-zero energy. The net zero concept is very appealing by taking
advantage of the existing infrastructure rather than having to create a full
independent power storage unit. Typically the consumption averages out to zero
over the term of a 12 month period.
The same concept can be used for the consumption of water; essentially creating an onsite
water filter systems. Water will not be able to quite be net zero, due to
evaporation and other environmental factors that are undoubtedly part of the
cleaning process. But a recycled water loop will probably be about 95%
effective. The remaining 5% can easily be made up by rain water or a well,
depending on the geographic location of the project.
The interesting part to me is the energy that is required to move and clean water.
By bringing this aspect of water use directly to the project, much energy can
be saved on the moving of water to and from the project and the reality of net
zero energy and water is much more realistic to attain.
Considering now, that in California for example about one third of the state’s energy is
used to clean and transport water, it does seem a little like putting the stick
before the carrot…
I am grateful to be part of a cutting research project at the University of Miami
that is addressing this very topic: The net zero water dorm. This project will
have move students into a retrofitted hall to be the live users of on-site
cleaned water – all water, from sinks, showers and toilets.
What can you do for your own project? Continue to focus on water reduction in daily
use and install conservation features in your renovation and new construction.
Dual flush toilets or even composting toilets are readily available. Low flow
shower heads and faucets are standard for all manufacturers and a rain
collection system such as simple rain barrel can be installed in any project.
Use the best suited system for water heating, be it on demand, solar or
conventional tank with a PV panel to power it. By using water intelligently,
the use of energy can also be reduced. Why not be the first house to clean your
Start your own water conserving project with http://www.SebastianEilert.com
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