I will be having a 3 bedroom timber frame house with a brick facade built on the side of my parent's 1930s semi detached house.
There is a main sewer on the edge of the plot running diagonally across the rear section of the proposed house which is why the new house will be attached to my parent's, to keep the load away from the sewer.
In view of this a SE has designed the raft and pile foundations as well as the structural design of the house.
We have a build over agreement with the water company to go ahead with the build.
The design includes the construction of a new block gable wall between the existing and new houses which will be tied into my parent's exterior wall using resin bonded ancon teplo ties.
The new block wall will be constructed off the new raft foundation slab.
My concern is that if there is movement in the new foundations then my parent's house will be damaged.
Should I pay another SE to check their design or is this a standard method when joining existing and new buildings?
Should there be a movement joint between existing and new foundations? A piling contractor mentioned dowling into the existing foundations??
Also should the roof have a movement joint where old and new meet?
The design appears to be very comprehensive with a 130 page document as well as additional pages but I do not want to damage my parent's house, or their attached neighbours!
Thanks in advance for any advice.
Sam