Hitchhikers guidee to the galaxy setting

In the book the Hitchhikers guide to the galaxy by Douglas Adams the setting of the story takes place on the planet Earth. The main character Arhtur Dent lives in a house looking over the West country farmland. His house is in a small village/town. But then aliens destroy the Earth and everyone on it, except of course the main character Arthur, and his best friend Ford. They escape the Earth by hitchhiking a ride on the Vogon ship that blew up the Earth. The setting then changes into being on a Vogon ship traveling across the galaxy.