Legal Advice on Construction Builder Lawyer

Require legal advice from a construction lawyer or retired construction lawyer before formal appointment to prepare legal letter. Would like to know our position especially termination of HIA contract. Budget depends on experience and what you can offer as I am not sure what is required. For general advice, would consider retired solicitor. For termination of contract, would need someone who is licensed. Please provide quote for everything you can do including letter of termination or issue of breach of contract if applicable. Signed HIA contract with builder. Paid up to lock up stage. Discovered multiple major and structural defects. However the biggest concern is that surveyor and builder are in collusion. 1. Permit was issued stating performance solutions report have been receieved to comply with BAL 12.5. No report exist. Surveyor rubberstamped permit. 2. No dts item was not listed on permit. Surveyor did not mandate builder to provide solution report. Issued permit without this. 3. Surveyor advised no photo or notes for the prepour stage and frame stage. Only gave certificate of competition. 4. Frame stage approved in early July. We have photos with medata 2 weeks after approval that frame in some area was not even erected yet. Damaged frame from fire not replaced. 5. RBS added notes stating frame in pergola will be inspected at final stage. Then realised this is a damning evidence, so rbs altered permassist record, took the whole link OFF the public, remove that notes. I have screenshot of this. I emailed RBS photos of defects and questioned his conduct. 2 hours after he sent termination of engagement and also issue form 13 to stop building works despite i asked for direction to fix. I have lodged complaints with BPC. But i need legal advice if i need to issue breach of contract to the builder so this was I can minimise financial losses, including potentially claim for rental, inflation, etc