By 1730, Brettingham is referred to as a surveyor, working on more important structures than cottages and agricultural buildings. In 1731, it is recorded that he was paid £112 (£ in ) for his work on Norwich Gaol.
By 1730, Brettingham is recognized as an expert in designing larger buildings, surpassing the scope of simple cottages and agricultural facilities. In 1731, it is recorded that he was compensated £112 (£ in ) for his role in building Norwich Gaol.