tiny house RMH plan recommendations ?

A rocket mass heater, doubling as a cooking appliance (stove + oven) and why not add hot water for the bathroom in a tiny house where space is ... tiny. Any plans available for such a multi-function RMH in a tiny house ? We really like the idea of a multi purpose RMH, but perhaps that is not dequate for our setup and you have other heating/cooking suggestions ?

4 * 3 meter (13*10ft) inside footprint with a 2.2 * 3 meter (7*10ft) mezzanine at 2.2 meter (7ft) high, and flat roof at 3.3 meter (11ft) from ground floor. (ft rough conversion)
In summer we get spells of 30°C (86F) and winter we can get -10°C (14F) weeks at a time with night time dips to -17 (1F) not uncommon, usually with snow cover. The in between season has temps all over the place.

Hello Star,   Not sure if you've seen Matt Walkers cook stove before:   Cookstove  Not sure if he's worked in a method of heating water with it as well (except in a pot on top) but I know many people have been happy with it and he has been very generous with his time to help you with your build.