A composting toilet is not an outhouse.

In a traditional outhouse — either in open ground hold or a concrete holding vault or tank, the waste collects and over time, turns septic.  Much of what contributes to odor is the waste being wet, and as a result, many people dislike outhouses.  There are great outhouse designs (see part 3 of this series) which eliminate the odor.

A composting toilet, typically separates liquid from solid waste, and layers the waste with wood chavings or peat or a combination, and through heat and natural bacterial, composts the waste into a compost fertilizer wich can be used on ornamental plants and flowers, not for human consumption.

Composting toilets, Sun Mar is one of the leading brands, are idea for both on and off grid locations in that they can operate with either 120 vAC or 12vDC.  I’ve used my Sun Mar Composting toilet since I moved onto Two Mile Ranch and have been pleased with the results.  I have rarely had an odor, and when I did, it was not more than any bathroom after use.  I have had a couple of the typical issues described in the manual (namely some slow drainage of liquids in humid months and a small fly infestation.  The liquids problem resolved easily with the addition of dish soap to break a film of grease on the surface, and the small flies were killed with pesticide.  The flies do not live — according to the literature — in the compost material, but do live in the composting toilet and once killed off, have been under control.

Like venting a chimney, it is important to vent a composting toilet high enough above your roof line.  There are users who report an odor while outside, but likley this is the result of down drafts or other drafting issues related to the exhaust of the composting toilet.

One of the best sites explaining the advantaged of composting toilets is The Natural Home Building Source ( http://www.thenaturalhome.com ).  Located in Colorado, the company offers a Website with dozens of detailed pages to help guide your choice of composting toilets and provides significant pre and post sale help.