Hi Chris and Linda, nice to have you here, we (my girlfriend and I) plan to build a natural house near Bogota, Colombia. It's in the tropics, but it's not hot: 14°C average, at 2600m above sea level, 900 mm precipitation quite well distributed during the year. Nights are usually cool year-round (5°C) and days warm (25°C). It's like a permanent central-european spring (or autumn). We want to heat the house somehow, in order to enjoy the evening reading books or playing, and to use the sun seems difficult, as we are close to the equator, and the midday sun is often vertical above the house. By the way, we have a design of the house in the cob section. So, here are the questions:
1) which natural material do you recommend, considering that we have clay and wood easily available? we strongly consider building a cob house.
2) if we build a cob house, and use a rocket mass heater to heat it, do you recommend to insulate to walls outside?
3) what kind of roof do you recommend? we strongly consider green roof.
4) is it ok to build a green roof with a 2° slope? the front wall would be 2.5 m high, the back wall would be 2 m high.
5) what is the insulation capability of a green roof? do you recommend, in our context, adding extra insulation?
6) do you think the exterior walls would support the roof alone, or should we build strong walls inside the house too? (please, have a look there:
https://permies.com/t/44551/cob/Cob-house-Colombian-highlands#353417 )
7) what is the best way to make the exterior plaster waterproof (against rain) as well as the walls where the shover is.

Is our context, would it be more easy to make a earth floor, or a wooden floor?
9) we would like to build a small storage cellar inside a hill, just outside the kitchen, any idea how deep it should be, and the best way to avoid rodents eating our food? How to prevent any moisture/water infiltration?
Wow, so many questions! don't worry if you can't answer them all

thanks a lot for you help!
I wish you all the best
greg