Given that I know nothing about the housing market in the UK, why would a house in a new suburb necessarily not be rented? Also, what is the numbering scheme that would put #11 next to #4? And are you assuming that the houses were new when the Dursley's moved there because of a detail in the book, or because it is indicative of the type of people that they are?

Sorry if this is bombarding you with questions - I wandered back to think about this, and realised there are so many things that I have no idea about.