David Balt

I suggest you use on site soil and amend it if you need to. You can always add lime or a very small portion of Portland cement that will really help improve the structure of your plaster. A few shovelsful of Portland will improve the plaster enormously without making it totally impermeable. My friend used soil "straight" after screening out most of the rocks, and 1/10 Portland. It dried nice and hard and has held up well.

I constructed a double-bell masonry heater in my new home as the only source of heat.  The house is 2000 sqft, and I live in an area where the temps get very low.  I also have two cantilevers in the design where the heat cannot directly reach the exposed portions.  Simply put, a masonry heater can keep an entire house very comfortable.  You simply build the right size heater for your heating requirements, and then you insulate until the house is comfortable with that amount of heat.  This season I am adding more insulation to the attic area to help with the coldest days.  I would advise anyone who likes the idea of heating with wood to strongly consider a masonry heater; the best part is that you are not feeding a fire all day, while still heating with a sustainable resource.  I also have an integrated oven, it's my favorite way to cook everything and a total joy to have.

What kind of regulations did you have to contend with in constructing this system? And do you get hard freezes where you are located?  I'm guessing not in CA?

It's really not a good idea to use greywater in this way.  You should never store greywater in a tank for any amount of time.  If you end up using the sink a few times per day and not using the toilet, or say you wash your hands then leave for a weekend, you will come back to foul, sinky water in the tank and possibly pathogens.  The rule for greywater is simple -- put it outside, right away, on the surface of the ground.  Never store, never pump, never hide.

I have just burned my brand new Masonry Heater for the first time ever... so I can give an example.  It is currently 10 deg. F outside, and the interior temperature is about 60.  After burning about 25 lbs of firewood in the heater for two hours, the exhaust temperature is about 60 deg. F.  I expect this will rise as the mass begins to saturate with heat, but quite simply put I am dumbstruck!