The chance of a flood or earthquake event happening varies from house to house. The data that we use to understand this risk is very comprehensive, and we now understand these differences in greater detail. This includes factors like the elevation, slope, and material of the land, as well as how close your address is to rivers and other waterways.
We combine this with information about your house and other factors specific to you, like your claim's history, and your age. These factors can be highly variable, even for houses on the same street. Therefore, one neighbour's insurance might be cheaper, while another neighbour's might be more expensive.