In 1731, it is recorded that he was paid £112 (£18,900 in 2022) for his work on Norwich Gaol.[3] From then, he appears to have worked regularly as the surveyor to the Justices (the contemporary local authority) on public buildings and bridges throughout the 1740s. Projects of his dating from this time include the remodelling of the Shirehouse in Norwich,[3] the construction of Lenwade Bridge over the river Wensum, repairs to Norwich Castle and Norwich Cathedral, as well as the rebuilding of much of St. Margaret's Church, King's Lynn, which had been severely damaged by the collapse of its spire in 1742.[2] His work on the Shirehouse, which was in the gothic style and showed a versatility of design rare for Brettingham, was to result in a protracted court case that was to rumble on through a large part of his life, with allegations of financial discrepancies.[4] In 1755, the case was eventually closed, and Brettingham was left several hundred pounds out of pocket—several tens of thousands, in present-day terms—and with a stain—if only a local one—on his character. Transcripts of the case suggest that it was Brettingham's brother Robert, to whom he had subcontracted and who was responsible for the flint stonework of the Shirehouse, who may have been the cause of the allegations.[5] Brettingham's brief flirtation with the Gothic style, in the words of Robin Lucas, indicates "the approach of an engineer rather than an antiquary" and is "now seen as outlandish".[1] The Shirehouse was demolished in 1822.[6]