See how Postgreen Homes may be interested in the Net Zero Water Project and read some dicussion on the topic here

As always, feel free to leave suggestions in the comments anywhere on this site, as every bit of information is helpful.

Responsible site selection is listed as the first prerequisite.  Of course it’s important to respect our environment, and it is also important not to interfere with any naturally-occurring systems such as wetlands or prairies.

Energy is obviously an important one here, as well.  All energy must come from the sun, and the building is required to be net zero energy, which means that it produces more energy than it consumes.

Material selection is also a major factor in LBC projects.  There is a “red list” of materials that is supplied with the challenge, and none of the listed materials may be used in any way during the construction.  These materials include CFCs, cadmium, Neoprene, HCFCs, formaldehyde, PVC, lead, mercury, pthalates, petrochemicals, and more.

Location and distance traveled of services and goods to the project must be kept to a minimum.  There is a radius around the site that builders/developers are allowed to draw their resources from.

All on-site construction waste must be managed and recycled.  There can be no waste produced from building a LBC certified building.

Of course, net zero water is a factor, and probably the one that most people tend to shy away from.

There are more aspects to a Living Building, but this post just serves as a general overview.  If you’d like to get a more comprehensive look at the LBC challenge, you can view a pdf of the LBC in its entirety here

The amount of rainwater available to a property varies heavily on the climate of where the property is and the time of the year.  In our region of Philadelphia, rainwater falls at a pretty even rate, but still fluctuates depending on the month.  Here’s a list of average rainfall for the Philadelphia region:

Treated rainwater will be primarily used for potable purposes, mainly the kitchen sink and dishwasher, as well as showers and bathroom sinks throughout a household.  If there is an overabundance of rainfall during a certain period of time, or a lack of greywater being produced and treated, “raw,” or lightly treated rainwater can be used for purposes such as irrigation, toilet flushes, and washing machines.

Living machines, which mimic natural wetlands, are used to naturally treat greywater.  This is accomplished through a series of stages involving plant and animal life.  The effluent of a living machine is clean enough to be used for a variety of things, but with some sterilization it can be used to drink.  After treating greywater through a living machine (which requires little energy due to gravity-fed compartments and natural systems of filtration), the water can be returned to the system for toilet flushes, fire suppression storage, washing machines, and irrigation purposes.  As I mentioned, it can also be further sterilized and used for kitchen sinks, showers, dishwashers, and other potable water users.

Here’s a conceptual model of how a living machine works, from a past project of mine:

Source: Achieving Water Independence In Buildings via International Living Building Institute

The key players in the system that produce blackwater are toilets, kitchen sinks/ garbage disposals, and dishwashers.  Anything that contains organic matter contaminates the wastewater produced with bacteria, viruses, and pathogens.  Good practices in the kitchen can limit the amount of blackwater to be treated by the system, but there will always be people eating and producing waste in the system, and these things require the presence of an MBR.

At this stage the water is not potable, but it is clean enough to be used for a variety of other things.  Once treated, the water output from an MBR can be used to refill toilets for flushing, irrigation needs, washing machine water, and to supply fire hydrants with water.

In Portland, OR, a group of professionals have banded together to work on a Net Zero Water project, the Pearl Family Development.  Although still conceptual, this project is well on its way to realization.  A non-profit organization called Central City Concern (CCC) provides affordable housing to low-class families in Oregon.  The CCC noticed rising costs of energy and water utility bills, and they set out to reduce such expenses.  They joined forces with SERA Architects, Interface Engineering, and Gerding Edlen Development to achieve net-zero water in the upcoming Pearl Family Development project.

This team of organizations is trying to achieve this goal for their project, of course, but they are also selflessly transparent with the information they garner about making changes and getting this system in place.  A lot of the research I’ve collected so far was informed from this team of people, as they are far ahead in achieving Net Zero Water.  Since this group’s coming together, enough research was gathered to make proposals to Oregon’s governmental bodies to get regulations and laws changed, paving the way for water independence.  Oregon residential and commercial buildings are now allowed to use rainwater for irrigation, toilet flushing, and clothing washing, and treated greywater is allowed to be used for flushing of toilets and urinals.

Portland is a great start, but what about the rest of the United States?  What about the rest of the world?  I live in Philadelphia, and I’d love to see Net Zero Water in Pennsylvania.  What will it take to get PA laws changed?  The Central City Concern, SERA Architects, Interface Engineering, and Gerding Edlen Development have drafted and released a “water roadmap” that explicitly lays out where each regulation or mandate comes into contact with a Net Zero Water system.  This is a huge help, and they are providing a great service to other people who want to do projects similar to theirs in different states.

Source: Achieving Water Independence In Buildings via International Living Building Institute