The Grand Designs presenter sets out on a mission to find out if a simpler existence really can make people happier, beginning by travelling to a desert island in the south Pacific archipelago of Tonga to meet a British family who have quit the rat race. Karyn, Boris and their three children live in an off-grid property, with no fresh water or electricity and face regular threats from hurricanes and tsunamis. Kevin finds out how they cope with these challenges and the psychological trials of having just one another for company.

The Grand Designs presenter travels to the foothills of the Andes in Chile to meet a family of five from south London who quit the daily grind to build a new home in the shadow of an active volcano. Kevin arrives at the site on horseback to discover that Jago and Lucy are still in the process of constructing their new home using bags filled with soil and timber from the local forest, which they transport by oxen. He is impressed by the structure, but troubled by one key question. Why choose to live next door to a highly volatile volcano?

Kevin travels to Central America to meet British family-of-five the Atkinsons, who have quit London to live a simpler existence in the rainforests of Belize. As he attempts to understand their motivations for the move, he suffers from the heat, is attacked by swarms of biting insects and shares his mud hut with a large scorpion, but begins begins to appreciate the rewards of a simple jungle life, one in which they've constructed a two-storey building entirely from recycled rubbish.

Kevin heads toward the Arctic Circle to meet Richard and Claire Rees, an intrepid Welsh couple who have given up their jobs and former lives to reside in a basic wooden cabin in the snow-covered forests of northern Sweden. Living completely off-grid, with no electricity or running water, and facing temperatures that can go as low as minus 30°C, simply surviving is a challenge. Kevin helps with the arduous, repetitive daily tasks of chopping wood and collecting water from under the ice, learning that a cup of coffee can take an hour to make.