building commencement

Hi all, FTB here. Ive had an offer on a house accepted, the surveyor acting for the mortgage advisor has been unable to value the house, on the basis that he has noted that there is structural movement in the form of cracking to masonry, and rhay i now need to get a structural engineer or...

I know it sounds self explanatory, but are there ways to 'commence' building works in a very small way? here's the situation: we live in a terraced house, been waiting to build our approved two storey extension for over a year. We are having delays due to one side who won't sign a party wall...