Cutting out fuel bills and the cost of mains water and sewerage will save him at least £1,000 a year, he calculates. That roughly translates into a before-tax income of around £1,500 - which translates, again, into less work, more time with the family and more scope for his favourite hobby, surfing.
"Nowadays, there seem to be fewer people in jobs doing more work and the result is stress. The families taking part all feel they would like to step back from this, from the business of careers and promotions. They view it as a way of taking greater control of their lives and of the services they need, of slowing down life a bit and getting more fun from it."
The Martins - Nick, his wife, and two children - are one of five families who will shortly be selling up their houses to move out to a gently-sloping but otherwise ordinary-looking field on the outskirts of Hockerton where their new earth-sheltered homeswill be built. Two of the other families have children.
The adults include a teacher, a social worker, sculptors, a clinical psychologist and a public relations consultant. Several are keen organic gardeners. All expect to work more from home, and will be required - by the rules of their co-operative - to putin about 16 hours a week on the project: growing food, for example.
The project will cost about £500,000 - about £100,000 per house, slightly less than the cost of a conventional, three-bedroom house with the same amount of space. Families will buy a lease from the trust - of which they are also members - ensuring that the houses can only be occupied by like-minded people and will not be "yuppified".
Hockerton is thought to be the UK's first underground "village" - most earth-bermed houses have been built singly, for wealthy enthusiasts.
Mr Martin does not believe the co-operative will intrude into people's lives - "it's just like any other row of houses" - and sees it as a "shift in balance" rather than a radical change of lifestyle.Reuse content