The former Towie star, 33, and his wife, 32, bought a £1.3 million farmhouse in Essex late last year.
They have now submitted documents requesting planning permission to demolish the building and erect their dream home in its place.
The new building will be a grand Georgian-style mansion compete with columns framing the front door.
According to the plans, obtained by Mail Online, they couple claim the current four-bedroomed property is not functional for their family’s needs and want to build a new home they have designed themselves.
They also say the new home will be of similar size to the existing building on the site, but will featured a ground floor bar, gym, TV room, study and an outdoor swimming pool.
The most telling addition to the build is a playroom, which could suggest the pair are finally planning to start a family.
It also comes shortly after Michelle quit her long-running role in hit drama Our Girl.
They married in 2015, and Mark has admitted work commitments have previously got in the way of their plans to have a baby.
Mark spent many months working as an entertainment reporter in Los Angeles, while Michelle has jetted around the world filming her TV show in locations such as South Africa.
Last year, Mark told The Sun: “We say we’re going to try [for a baby] every year but something comes up with work,’ the presenter said.
“So it’ll be Michelle filming in South Africa and then I got the job in Los Angeles – so we think, right, we’ll try next year.
“It’ll be around December or January, we’ll talk about it and we’ll go from there.
“With kids, I used to want three or four. But now, I’m 31, we’re not having kids any time before 32. I think we could have two or three. Twins would be great because you’re getting two out of the way at once!
“Triplets would be even better! And if we have quadruplets we’d be laughing because we’d have them all in one go!”
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