posted 7 years ago
If structural load is your main issue, and the basement below where you would want the RMH is not finished living space, it is totally possible to build piers or other foundation to support the heater on the main floor. This obviously adds to the work and expense, but the typical RMH load is spread out enough that there is not a major point load like you would have with a traditional masonry heater. In fact, for some RMH installations, it is possible to spread the load over existing floor joists with no or minimal reinforcement. In your case, you would want a larger system which would likely require dedicated support.
The heating effectiveness of a system in the living area, and ease of tending it, will quickly repay the effort of building supports.
Another possibility is what I am planning for my best friend's house. It has a tiny 200-year-old core with no space for firebox or barrel clearances, but a large 1950s fireplace/chimney mass near the center, and a basement below. I am going to build a batch box combustion core to minimize tending, and a two-story masonry bell which will bring the hot zone up into the center of the living area adjacent to the existing chimney mass. This only requires a new spread footing on the basement floor and a hole cut & framed in the main wood floor.