Sofie Allsopp's homing in on big sister Kirstie

After all, how many people called Allsopp can fit on the small screen, telling us what's right or wrong about our dreary, unsellable homes?

It's only natural, then, that first thoughts probably turn to Kirstie, the Channel 4 "Location" shows she co-hosts with sparring partner Phil Spencer, she who is currently on our screens revamping an old property's jaded interior using handicrafts and dying skills and – of course – she of probably the most desirable shoe collection of any television presenter.

Snapping at those stiletto heels, however, is another Allsopp.

Sister Sofie, it transpires, is a slightly younger model who bears the same surname and same fascination with property. She even speaks with a definite twinge of the "Kirstie" drawl.

With a BBC property show of her own, she is definitely shoehorning her way right into her big sister's Manolo Blahnik heels.

Edinburgh-based medieval history graduate Sofie, 28, can currently be seen fronting daytime homes show Unsellables – a 30-minute romp around a house that has stagnated on an already fairly static property market, picking over the reasons why it hasn't sold.

It might be a recipe for a sisterly showdown, but Sofie insists big sister Kirstie, 35, has supported her from the minute she sailed through a screen test – for what should have been her own sister's presenting job.

"Kirstie was pregnant and they wanted someone to fill in for her on a show with Phil that looked at the ten best and ten worst places to live.

"I was asked if I wanted to do a screen test. I worked in property and I knew Phil and most of the crew anyway from having visited Kirstie while she was working, so it went well.

"I got the job and while, OK , I was probably given a foot in the door because of Kirstie, I like to think it was on merit."

She certainly found her sister's shoes a perfect fit. "I really, really enjoyed it," she nods. "Everyone was great, they helped me a lot, so I found being in front of the camera a really comfortable experience.

"And Kirstie has been brilliant. She said at the start that I should just be myself, try to be as confident as possible.

"People would love to think that we're fighting all the time but, honestly, we're not!"

She clearly made a big impact with a rival production company pulling together a new homes show for Canadian television. They saw her

Turning housing nightmares into dream homes

confident performance and swooped to sign her up to join them in Quebec, filming Unsellables there.

Sofie was well into filming the mammoth 26 episodes when news came from the BBC in London that it , too, was keen to buy into the Unsellables concept – with her at the helm.

"The whole idea for the show is helping people to make their homes ready to sell – it's about making the best of whatever property you have, decluttering, painting, getting rid of smells or things that don't look so good," she explains.

"We all become too familiar with our surroundings – you don't see things the way a buyer does."

All of which is of vital importance for anyone attempting to sell during these days of recession – but even the best touch-up job can't make someone buy if they're not in the mood.

Even Sofie admits her own househunting has had to go on hold until the rollercoaster property market finally levels out.

"I was househunting in Edinburgh, but gave up. It was too expensive," she laughs. "Actually, we reckoned that it wasn't really the right time to buy, and instead thought we would just wait and see what might happen with the market.

"So now we're renting a Georgian house in Stockbridge.

"It's a lovely house but if it were mine I'd be knocking down walls and doing a bit of work," she adds. "It's a little bit scruffy but, yeah, I suppose you could it 'shabby chic'."

The "we" she talks of is her and new fianc, freelance writer Rob Fletcher, also 28. The couple met while at university and announced their engagement last month. The plan is to marry this winter amid the rather more substantial surroundings of her parents' English home – her father is Charles Henry Allsopp, 6th Baron Hindlip, an art historian and former chairman of Christie's.

Of course, that's assuming Sofie can fit planning a wedding around a gruelling filming schedule across the pond that involves travelling around Quebec, crew in tow, advising demented sellers on how to declutter, neutralise the paintwork and just plain clean up their homes if they actually want to clinch that property deal.

"It's a hectic year," she grins. "I'm having a break in Jura then I'll be in Canada filming, then trying to organise a winter wedding!

"My carbon footprint is rather bigger than I'd like. But it's been brilliant."

The Canadian show has propelled her presenting skills to an entirely different audience from big sis Kirstie. "They seem to like the fact I've got this English accent telling them what to do," she chuckles.

"But the show works there as well as here – the houses might be different, but the issues are the same."

So far the BBC show hasn't taken her to any nightmare homes in Edinburgh, but she admits coming from the Capital has been handy when it comes to filming in the depths of a Canadian winter.

"We did end up filming parts of the first season during winter when the temperature was down to -27C. That's where it was an advantage to have come from Edinburgh – you're used to the wind chill living here!."

She arrived ten years ago to begin her history studies at Edinburgh University, fell in love with the castle on its rocky outcrop, the diverse city centre properties and, she adds with a wicked grin, the pubs.

There was a brief spell back in London working as an estate agent in Notting Hill before she found herself "lured back by the bright lights of Edinburgh".

"This is home for me now," she confirms. "You just have to walk out of the railway station and see the view and it's just the best thing.

"Compare it to walking out of King's Cross Station in London. You step out and think 'oh . . . NO'."

It's finally a chance to put down some roots – her childhood was spent packing and unpacking as her parents drifted from one property to the next, developing houses while she, Kirstie, younger sister Natasha, 22, and big brother Henry, 34, heir to his father's title, squabbled over who got the biggest bedroom.

"I really got on well with Kirstie when we were kids – if anything it was Natasha that I'd fight with," she giggles.

"And although not everyone appreciated moving so often, I found it exciting.

"I suppose it's because of that childhood that we've all got such an interest in property," she nods.

"It really must be in the genes!"

The Unsellables is on BBC1 on Monday at 10:45am and Tuesday to Friday at 11am.