Alderman Simpson was sometimes described as the maker of modern Harrogate. His development of the Duchy Estate, the chief residential quarter, accounted for a considerable portion of the increase in the rateable value of Harrogate from £200,000 () to £420,000 () between 1901 and 1925. He always aimed at dignity and variety, and the preservation of amenities, holding that it was these features in development which gave character and distinction to a town.
