Rocket mass heater plans are available at Richsoil.com and via various links provided by the website. Richsoil also sends out an email about permaculture topics approximately every week, and many of these emails contain plans or other information about rocket mass heaters.
A rocket mass heater is a type of home wood heater that has a reputation for being extremely efficient and environmentally friendly. These heaters produce a fire that can heat a home for an entire day using up to 80 percent less wood than conventional wood heaters. They are designed to create a convective current that keeps smoke and heat inside the heater, reducing the fire's exhaust to mostly carbon dioxide and steam rather than smoke.