Thanks Glenn for your advice! Ducts, pipes, wiring..etc do not need to be in that exact spot at all. Actually, I quite like idea of using the wall between bedroom and kitchen for bell. Yes, chimney can be buried! It is suspended flooring slightly above the ground, 200mm insulation / rock wool or alternative..
We have 4 seasons, however, winters lately are quite mild.. above / below zero Celsius. Sometimes drops to -10 / -20 or even -30 However, current average this year is zero Celsius.
According to the project there might be large windows facing south, triple glazed, basically, the whole wall and about 2meter overhung to protect from summer sun. See attachment, please.
Insulation - rock wool or other environmentally friendly material 200mm (walls)on top of that 50mm fibrolite or plasterboard or timber boards or even combination of all. Roof insulation 300mm.
Upper floor is open and covers 2/3 of the total floor area, so, living area on ground floor is a huge open space up to the roof ridge on the south side... As heat rises my assumption was that there probably won't be a need for stove upstairs... except some sort of 12V ceiling fan above the living area..