The space between the outrigger and garden wall was so small it was decided not to move the soil stack onto the external wall insulation as this would reduce the space and put it in a position where it would obstruct the view from the back windows.
Locally grown larch boards, sourced from Treestation.
Larch board installed around cill
An air admittance valve was fitted to a shortened stack, then EWI installed leaving a space around the drain inlets and soil stack. This was separately insulated and covered with a UV resistant water barrier, covered with local grown larch boarding from Treestation. This deals with the soil stack and breaks up the expanse of white render, adding visual warmth
Further information is available in the Retrofit Pattern Book