A house extension turns space you already own, a side return, a rear garden strip, a footprint over a garage, into heated, insulated, everyday living space. In most Cannock and Staffordshire homes that means one of three things: a kitchen-diner that the whole family can sit in at once, a ground floor bedroom and wet room that lets someone stay in their own home, or a first floor bedroom and en-suite that stops a growing family having to move.
The comparison people are really making is not extension versus no extension. It is extension versus moving. Once estate agent fees, stamp duty, conveyancing, survey costs and removals are added up, moving takes a large sum of money and returns none of it to the property. An extension spends the same kind of money on the house you already like, in the street you already chose, near the school you already use.