A home fit for the future is on offer in the Cumbrian countryside – but you have to build it.

The unique expandable home could be built at Cotehill after planning permission was granted on a building plot which has now gone up for sale.

Not only has it been designed to evolve as family-life changes, but also uses the latest eco-friendly technology to make it affordable to run and build.

The plot costs £115,000 and Carlisle architects Black Box estimate the Grand Designs- style house could be built for as little as £85,000.

Stephen Fox, who owns the land and lives next door, said: “It is a very interesting building – very new age and eco friendly. It has a timber frame and solid walls.

“It’s unique. It looks over the Settle to Carlisle railway line so it has good views.”

The plot, known as Netherdoodle, is on the market with Cumbrian Properties.

The particulars say: “The Grand Design -type property has been thoughtfully designed to take advantage of modern technologies and laid over one floor to appreciate the location and excellent views.”

Architect Malcolm Wilson explained: “It is a prototype house, not your generic house type, and it can have two, three or four bedrooms.

“You can expand it to suit a growing family or reduce it for a smaller family.”

It is designed so that internal walls can be moved into alternative positions, to change the number – and dimensions – of rooms.

The energy-efficient house would have no cavities, but a high performance membrane roof with timber cassettes. Its solid block walls give shelter and a robustness.

Mr Wilson added: “It is built in an L-shape [and] you enter in the middle of the house.

“It is very economically built and the plan is flexible. It is very similar to a post-war prefab.

“It would take about four months to build – a lot of the work would be done off site in the joiner’s workshop.”

Mr Wilson added that the house would be “warm” because it has a high thermal capacity.

“It would suit a growing family or a retired couple. There are no stairs to worry about as it’s all on the one level,” he said.

Mr Wilson praised city planners saying they had been “great”.