If you go down to St Johns Wood this week, you’re sure of a big surprise. Taking over two enormous mansions on Hamilton Terrace, the annual Holiday House has finally transferred to London, celebrating its 10-year anniversary with its first edition outside of the US.

For those still unfamiliar with the New York initiative, Holiday House is an interior design exhibition with a difference. Similar to its NYC forerunner Kips Bay Decorator Show House (which was started in 1973 and raises funds for underpriviged youths in the Bronx area), the Holiday House invites top interior designers and brands to each transform a single room of a dedicated house, according to the theme of past holidays or experiences that have a personal meaning to them. More than that, Holiday House strives to make a difference, with proceeds from all ticket sales raising crucial funds (well over $1million so far) for the prevention and cure of breast cancer.

Founded by breast-cancer survivor and philanthropist Iris Dankner and co-chaired by interior designer (and now UK creative director) Rachel Laxer together with philanthropist Joyce Misrahi and marketing chair Grant Pierrus, it’s a stellar list of talents participating in the London properties. Visitors can flit up and down the sweeping staircases taking in the imaginative flair of everyone from Nicky Haslam to Fiona Barratt-Campbell. Twenty five rooms have been decked out by the likes of Patrik Lönn Design, Justin Van Breda London and Nina Campbell. Sophie Paterson Interiors, Natalia Miyar Atelier and Taylor Howes are all there too.

Personal highlights include the Think Tank by New York designer Catherine Weinstock – featuring pieces by Doshi Levien alongside sculpture by Simeen Farhat and African hardwood chairs by Babacar Niang; the Hermès by Dedar wallpaper-lined Travel Writer’s Den by Patrik Lönn. The lovely Invisible Collection, which commissioned Bismut & Bismut to create their space, complete with handcrafted wallcoverings and a Very Hairy Chair in deep plum, is another must-see.

With 2017 marking 20 years since she has been cancer free, Danker has made it her mission to raise funds for research and to support women fighting the disease. “I vowed throughout my treatment that I would do whatever I could to help find a cure for breast cancer and help other women,” she says. “So I started fundraising, and after 10 years of that I realised that there were no fundraisers in my own industry that benefited any women’s issue. I came up with the idea to do a designer show house… It was just a dream I had. It’s grown beyond my wildest imagination.”

Laxer, who is based in both New York and London, is largely responsible for making this anniversary edition a reality. The trio were keen to find a property (or indeed, properties) that would be both inspiring for the designers and interesting to the public. “I thought they were perfect,” says Laxer. As Holiday House is about the celebration of life, each day treated with the same reverence as a holiday, both houses – one themed along more contemporary, international lines, and the other more “English with a twist” – reflect an upbeat, positive mood.

Dankner, Laxer and Misrahi are understandably over the moon with the talent they’ve managed to pull in for the event. “We’ve received so much enthusiasm from UK-based designers and brands. And it has just snowballed – you know, we called a friend and then they all pulled out their contacts books, and now we have this incredible community and everybody has been so kind, and really come together.”

Every room has “a wow”, says Mishari. “This is an opportunity for designers to express their creativity without having a client directing them. It’s pretty interesting.”

Art is playing a significant part too, says Danker. “It’s one of the things that’s been hugely influencing the interior design scene in New York and I see the same thing happening in London.” As the art galleries began to become involved in holiday house, she decided to put together an auction. Works donated include a Bronze Painting by Pierre Bonnefille and Her Majesty by David Yarrow.

For those who don’t manage to pick up a piece in the auction, or decide to take home a dressing table, console or chandelier from one of the rooms, this year also marks the launch of the book. Holiday House: Ten Years of Decorating for a Cure is a gorgeous tome documenting Holiday House’s history from Pointed Leaf Press. Or there’s always the houses themselves – both are now on the market for around £23m from Savils and Knight Frank.