Differential movement in extension

[Jilly]

The main building is made of block with 600mm foundations, (external insulation and weatherboard), the  extension has to be piled (trees and clay).

 

I'm struggling with the decision of whether to continue with block (which seems logical) or to use  timber frame.  I'm wary of the differential movement and had assumed timber will be more forgiving. We are planning to use a compressible material, but are there other things I should be considering? Is insurance more straightforward if the building is all the same construction?

 

CHIMNEY floorplan copy.pdf

[PeterW]

Timber will move on it’s own as it dries so it’s either a quick way to cracking (timber) or a slower way if the piles do move (blocks)

 

I would go blockwork. 

[Mr Punter]

With 2 different foundation systems and on clay there may still be some differential movement.  Perhaps design in some movement joints between the existing and extension.  Stick with blockwork.  Maybe use cement based weatherboarding?

[tonyshouse]

I always like to see non but joins, internal corners, 20mm steps forming internal corners , non mortar slip joints