My extension wall will be fairly tight to my neighbour's land. I had expected to construct the timber frame and then clad it in concrete block, using wall ties in the ususal manner. However he has refused access to his land so I will have to build the concrete wall first, from my side, and then tie the timber frame to the now existing wall. Obviously the frame will be sheathed with OSB and covered with building paper. So how do I tie it to the wall?