Thanks Ravima and DirectDevl for replies. We did not know there was a difference between periodic site visits and supervision. The fee was 11k. We also did not know the difference between Opinion of Compliance and Cert of Compliance. The engineer in question never informed us of these differences. The new engineer, a Chartered Engineer, who would be well known and thought of in engineering circles said that the fee we paid, 11k is far more than would have been considered for periodic site visits, and that the fact that the original engineer designed and tendered for the project as well as stating in many correspondences that he was the supervisor of the project, the administrator of the building contract and that all design changes and cots had to go trough him, the building contract also refers to the engineer as the supervising engineer, and this meant that though the original contract said periodic site visits, the implied contract was supervision. The engineers professional body thinks he wasn't less than diligent in his supervision as he was making periodic site visits, and that he has no case to answer re supervision, but did have case to answer on other issues, e.g. CPD, competency etc. though there was 80k of remedial work required, including insertion of two lots of steel supports to make the structure safe, among many other issues. We also never obtained the correct certification for him. Re. our planning cert, he wasn't able to give us that as he was not a Chartered Engineer. We still do not have full certification for the house. The new Engineer says that the original engineer should have supervised the renovation at key points, foundation, blockwork, roof and attic conversion/supports.