Insuring a home with a rocket mass heater

My county mutual will insure a manufactured, UL listed wood burning appliance, which most insurance companies won’t touch.  However,  a wood-burning home-made appliance is another matter!  In fact, he sees the heat-absorbing thermal mass as a bug, not a feature, as he equates cool exhaust with creosote buildup and chimney fires and claims for replacing houses, which both of us want to avoid.  My Dad’s childhood home burned down at -40F, leaving them living in the barn, so I know what he means.

So if someone could point me to the truth of the matter, and an insurance company that will insure a house with a rocket mass heater, that would be most helpful.—Marv

The truth of the matter is that a properly built RMH (following published guidelines such as found in _The Rocket Mass Heater Builder's Guide_ by Ernie and Erica Wisner) will have zero creosote in the exhaust, as it all burns up in the combustion core.

As for insurance, I have heard that there are some enlightened companies, but more that won't touch it. A critical tip for getting the best possible consideration is to leave out any mention of "rocket" and talk about a masonry heater. RMHs are a subset of masonry heaters. Traditional styles of RMH with a barrel will in realistic terms need to follow wood stove code for the barrel and masonry heater code for the rest.

What a fabulous set of information, thank you!

Years ago my parents bought a house from my grandparents. When they brought their insurance agent in, he saw the manufactured woodstove, got it's dimensions, and called it a "Wood burner." But in a different room in the house there is a janky wood stove insert that my Dad built as a high school welding project. My parents gave the insurance agent a rough description. He sent me with a tape measure to get it's dimensions, and he called it a wood burner. He didn't even look at it himself. He sold my parents a home insurance policy through All State Insurance (if I remember correctly) and that was that.

I have lived in several homes with wood heat, one with propane. I haven't had an insurance company do anything other than send someone out to inspect the stove - but I have heard of some requesting a copy of the permit info for the stove.

A rocket mass heater can be permitted in some jurisdictions as a masonry heater.  I'm in an area still using 2012 IRC as the building code.  Here is the Chapter that applies to masonry stoves:

Chapter 21 of 2012 IRC -Scroll down to section 2112 for Masonry Heaters

Please note that you need to scroll down on this page to get to the Masonry Heaters section.

In that section, it then says that a masonry heater will be installed either according to the manufacturer's guidelines, or using ASTM E 1602, which can be bought here:

ASTM E 1602 - Standard Guide for Construction of Solid Fuel Burning Masonry Heaters

Technically, people building masonry heaters are supposed to be experienced - or guided by an experienced installer.  I think this is where if someone wants to attempt building an RMH and having it be successfully permitted, getting consulting from one of the awesome RMH builders (who have dedicated their lives to this work in a most amazing way), could be a path to success.  Nowadays, that could be done virtually.

Is there a clause in your home's insurance policy that says you must call them if you add a wood burning store?

If so like Glenn said tell your agent that you are adding a masonry heater.

I feel that once insurance companies learn more about RMH they will be more lenient and accepting.

This is where this thread will help:

https://permies.com/t/191709/people-rocket-mass-heaters

The more people that know about RMHs then the more that will be adding them to their homes and that way more insurance companies will know about them.

Let's get the word out.