RMH planning questions

I got a set of questions in a PM, and thought a version of my answers would be helpful for other people.

1. Is it viable in an indoor residential situation? The house I am trying to build is about 2500 square feet.
2. What about the smoke and carbon monoxide?
3. Will the insurance company accept it being built by a certified rocket mass heater builder (if there is such a thing)? Also, I know there is a certified masonry heater group accepted by insurance companies.
4. I also know about the UL-certified Liberty Rocket stove. But I believe the "mass" element is missing in this solution.
5. Lastly, do you know someone who can build it for me? and what does it cost approximately?
6.  I also do not want a cobb-looking heater. Something that can be covered with tile or brick.

To briefly answer your questions:
Yes, a rocket mass heater is quite viable for residential heating in our climate [upstate NY]. 2500 square feet is good sized, but if designed for a mass heat source can certainly work. This means a fairly compact, well insulated layout with a relatively open plan, or the heater in a dividing wall so it can radiate to multiple spaces.

There will be no smoke and practically no CO during RMH operation, only for a few minutes at startup and possibly the end of firing.

Insurance companies differ, and you would need to talk to several to find out their policies. It is important to use the term "masonry heater" rather than RMH here, as masonry heaters are explicitly in the building code and accepted in general. RMHs are a subset of masonry heater. There are not currently certified RMH builders, but a certified masonry heater builder (from the Masonry Heater Association or possibly others) could build a RMH.

The Liberator ships as a rocket stove, but it can be connected to a site-built mass to store much of the heat generated. It would probably not be the most efficient overall, but it might be the most efficient insurable option.

I am experienced and could build a RMH for you, although I do not have an official certification. Cost is an open question depending on a huge number of variables. It would likely be between $3000 and $10,000 depending on how fancy and how many brand new materials are wanted.

Any noncombustible material can be used for the outer skin, so brick or tile is easy (but probably more expensive than a plastered surface.)