Simon Baker, 52, sold his one-bedroom flat in London to buy an abandoned Eryri cowshed in the Machno Valley, north Wales.

Investing all his savings into purchasing the land, Simon admits it was a “huge gamble” as the shed had no planning permission.

But he doesn’t regret having to spend cold nights camping in the back of his Ford Focus while the old stone building was renovated.

And the now modern hangar – which probably dates from 1760 – was a finalist in the BBC A Wales House Show of the Year.

Simon said: “When I saw the shed I fell in love with it – it was a heartfelt decision. Everyone in my family thought I was crazy.

“I always wanted to do a construction and restoration project. And I saw that this property had been put up for auction in 2013.

“It was for sale without any planning permission to convert it. I saw it online and thought it looked like a project that might be a good thing to do.

“With the right support and a bit of luck, I was able to make it happen. I bought it before the auction and then some of it fell off, which was a bit worrying.”

Prospects for renovation did not look promising as the shed did not have planning consent and was subject to a National Trust restrictive covenant – which required their consent.

And the building was an abandoned and ruined stable, never inhabited, with no access or services.

But after carefully preserving the surviving elements of the old stable, Simon incorporated some clever interior design tips – and Welsh roof slates from the Cwt-y-Bugail quarry, just 2 miles from the stable .

He also worked with a number of people locally to understand how best to restore it.

“There was no point in loving the place and completely changing it. I wanted the stone to be visible in all directions in the barn,” Simon said.

“I had a fantastic local builder who I managed to convince to join me on this journey. They have worked in these types of buildings all their lives as they tend to do it true to tradition.

“It was quite difficult to fit everything in and I realized that the best way to use the space is to have a curved staircase. And once I realized that was the best way to do it, everything the rest had to be installed on curves.”

He explained that although he was “a little scared” by the construction task, it was an “extremely rewarding process” to live in a space designed by himself.

Simon said: “It fits perfectly with my lifestyle and is extremely rewarding.

“The land was affordable by today’s standards. I took a huge gamble in purchasing the land because I had to invest all my savings into purchasing the land up front.

“And it was a huge risk because there was no authorization.

“When I bought this I was living in a flat in south London – it was a big change. It was a big step to get the project started – which presented its own challenges.

“I was a little scared. Building it is quite interesting because you start at the beginning with control, then somewhere in the middle you lose control and you have to finish, otherwise you risk losing everything and you have to keep moving forward .”

Where possible, the old beams of the hangar have been preserved. And from the outside, the shed looks a lot like it would have looked in the 18th century.

He added: “I have done many conversions and have always been interested in the design of buildings. I owe a lot of that to my father who was a handyman – my father was probably my inspiration for doing that. “

In order to thank those involved in the renovation of the shed, Simon decided to apply for BBC Wales House of the Year Awards.

And reached the final which will be broadcast in December.

He said: “I’m not interested in publicity. I wanted to pay tribute to the local people here who have worked so hard for this.

“The wonderful thing about doing a self-built project is that you feel like you’re part of the community.

“You buy all the materials from local people and many of those who worked on it are very close friends. The builders are grazing some sheep in my last field.

“It’s my forever home. I loved living in London and I still have to go there from time to time. I’ve always loved having contrast in my life.”

Simon, who works for Network Rail as an incident manager, says he is even learning Welsh at the moment to be part of the community – as it is their first language.

He added: “People in the village remember milking cows when it was a stable. The National Trust told me it dates from 1760 – it is quite old but the reason it became derelict is that it is too small for modern agricultural needs.

“I can look around the valley here and they are in different stages of disrepair. Once the roof collapses with the strong winds and the pieces of stone start to be reused, they just disappear.

“I felt like I could save the life of this humble little barn and preserve it for future generations.”