Hi. What number did your ancestor live at? My great grandparents lived at No.3 Clara Place, Topsham during the 1930s-60s. They were Wallace & Annie West. I've been told that the landlord couldn't afford to keep the house in proper repair, and that they rented the property for 2/6d.
No.3, as far as I remember my mother showing, was in the left hand corner. The numbering you are referring to is likely a modern renumbering of the houses done for postal purposes and standardization of addresses. Renumbering houses in official records often happened throughout the country as more houses were built, the postal system expanded and new road layouts were developed.
Clara Place used to be the site of the old workhouse, and the memory of that lingered on for many local people. Living in Clara Place was looked down upon by some.