Designing a wood heater (product design degree)

Hi everyone!
I am currently doing the last year of my product design degree.
I have chosen to design an eco friendly heating solution that utilize local material and can efficiently warm up an unmodified domestic setting using industrial and agriculture biomass waste as fuel.
The idea is to design a stove skeleton that has a low transportation footprint and weight. The end user then is able to use locally sourced materials like cob, rocks, etc to finish the stove off and
maybe even have some degree of customization.
Just want to ask what would be your perfect wood heater? what features would you want on it?
Also if you were to build a thermal mass structure out of cob, what would you build?
and finally if you have built a heater, what did you find hard or inconvenient about the build process.

Any input and suggestions will be GREATLY appreciated!!!
Thanks all in advance!

Harry

Hello Harry, welcome to permies!

You might get some ideas of our favorites, and building styles of them,in the rocket stove forums.

https://permies.com/forums/f-125/rocket-stoves

Take a look at http://dragonheaters.com and http://walkerstoves.com
(products)