Thanks Leo, Seagull, Twofort for your replies.
The guy actually apparently has a degree in Civil Engineering and is in IEI, and seems to have been in practice for 14 years, but really got so many basic planning rules wrong, and there was so many compliance issues, issues that contravened building regulations - it's hard to believe that he has escaped this long without being sued - it's such a mess, drainage issues, everything.
Currently looking at suing builder for breach of contract and engineer for negligence. Just wondered how can he keep promising Certificate of Compliance and not give it - final inspection was last Sept - I have ancillary certs on Opinion on Compliance for him for Radon, Damp Course, Foundations (builder supplied Cert and also Cert re no pyrite), RECI, REGI, Insulation, but not the Cert of Compliance for whole house.
Apart from huge mistake he made on planning which means we had to go for retention. He didn't alter the drainage of the original house - leaving it still with foul and rain water together - this is apparently against building regs, but most old houses apparently had combined systems like this, but he should have altered it, and it was a condition of retention that he supply map of drainage and explanation of why he did this, but has not approached Council at all, and the date is fast approaching for submission of this information.
A complaint has been made to his professional body - people like this should not be allowed to practice.