Because I thought I was on the Llansannan site.
However, where I live in Anglesey, The local archives have all the House Rates back to 1745. I have used these to find all the houses in my parish to this point and beyond. In 1608 every house /field was taxed. these can be found in the Public Record Office. Also, there was the Tithe Rate Assessments in 1910 and the Tithe Rates abt 1840. also you can find closer to date on the 1939 Register. Best of luck, however if you are in Llansannan, Denbighshire I am researching that area.