Many lenders require a 10 year structural warranty policy on new build and renovated projects. Without a warranty you may be limiting your potential market of buyers. A fairly recent court case highlighted some of the problems associated with reliance on architects certificates. They are an extension of the architects professional indemnity cover and as such you will need to be able to prove they were professionally negligent. Additionally, if the architect is no longer in practise or fails to renew their cover it can often lead to no protection. For more information: https://www.thenbs.com/knowledge/court-of-appeal-provides-clarity-on-architects-certificates