We’ve seen all sorts of things being built on Grand Designs, from a sliding house on railway tracks, to a home made of wood that is 100 per cent sustainable.

Ham & High: The exterior of the contemporary box-shaped houseThe exterior of the contemporary box-shaped house (Image: Paula Beetlestone (Channel 4 images must not be altered or manipulated in any way) CHANNEL 4 PICTURE PUBLICITY 124 HORSEFERRY R)

Many of these projects cost an astronomical amount of money, but one London couple recently managed to design and build their dream home in Muswell Hill at the same time as saving £400,000.

Penny Talelli and Mark Edwards, who were featured on this week’s episode of the hit Channel 4 show, were originally told by builders that it would cost them £1 million to build a house on a plot of land they bought with an old Victorian gatehouse - which in itself cost £725,000.

Ham & High: A music roomA music room (Image: Paula Beetlestone (Channel 4 images must not be altered or manipulated in any way) CHANNEL 4 PICTURE PUBLICITY 124 HORSEFERRY R)

As they only had £600,000 to spend, the neurologists decided to do the project managing, and much of the designing and building themselves. As a result they shaved £400,000 from the cost of the project.

Their plan was to restore the gatehouse, that sits on a steep hill, and add a modern, zinc-clad black box onto the back of it. In the end however, they decide to knock down the gatehouse, and rebuild it alongside the contemporary box.

Ham & High: The main bathroomThe main bathroom (Image: Paula Beetlestone (Channel 4 images must not be altered or manipulated in any way) CHANNEL 4 PICTURE PUBLICITY 124 HORSEFERRY R)

The episode provides viewers with an in-depth look at the build, which took two and a half years in total, and shows how the couple face various problems and delays, often due to issues arising from the steep slope. But, through typical ‘Grand Designs’ determination, they finally see their dream home realised.

On the show Mark said: “It shows you what is possible, I think, by doing it yourself. We’ve invested so much time and thought into all the different bits in it that when you see them it does something good for you inside.”

Ham & High: The original Victorian gatehouse was taken down and rebuiltThe original Victorian gatehouse was taken down and rebuilt (Image: Paula Beetlestone (Channel 4 images must not be altered or manipulated in any way) CHANNEL 4 PICTURE PUBLICITY 124 HORSEFERRY R)

“It has an internal consistency because it’s the story of us, the story of both of us…somehow it’s all in here.”

Watch the episode here.