I'm a bit confused by the questions. Are you wanting to make cob and wrap a house with it? Not sure that would do much to help with the cold as it isn't very insulated but functions off of thermal mass. Also, you won't want to use sand, cement and wood chips for making cob. The cement and sand would most likely just make really crumbly cement and the wood chips would make it worse. The purpose of clay is to act as mortar for the sand and the straw acts as a fiber that binds the mass together like re-bar. If i were to wrap an existing building I would use straw bale or just build new altogether.
Yeah I think I need to do some more reading on cob before asking questions.
Thanks Daniel. It won't be for this season.
I was asking because the house needs some major repair. And there is a lot of wood chips and sand at hand. I was thinking of redoing the exterior with cob. The wooden frame has to be replaced too.