This week, the designers arrive in Brighton and find out it's time to work solo.

Michelle tells them to get into the spirit of the staycation, as they're off to north Wales to a glamping site. With a chance to showcase their individual abilities, they'll each have a shepherd's hut to transform into a boutique bolthole in the tranquil Welsh countryside.

With only five designers remaining, competition is getting tough. Before they get going, Michelle gives each of them a bespoke brief and tells them their client is a brand new business, so they need to work their magic. They'll be designing their smallest spaces so far, so practicality is key, but they must also be sympathetic to their surroundings. With so little to choose between them, she tells them that she wants to see hands-on skills – as well as maximum creativity.

The designers arrive on the Llyn Peninsula near the Welsh coast and are impressed with what they find at the site. The newly built huts are a blank canvas, with one designer worried that they might ruin what's already a lovely space. With briefs ranging from rustic chic to romantic, each designer takes a different approach to turning these tiny spaces into luxury living accommodation, with the challenge of an ensuite shower room and an outdoor space thrown in for good measure.

As the challenge comes to an end, the storm clouds roll in, as do the judges, Michelle and the legendary Laurence Llewelyn-Bowen. Two huts strike them as pitched perfectly at the target market, but they are less sure about the other three, questioning whether the designers have taken the right approach for the rural surroundings.

It's semi-finals week, and the remaining three contestants are aiming to deliver their best designs to date, in the hope of winning a place in the big final.

Michelle reveals that for their next project they will be working solo. Each has a luxury holiday lodge to upgrade, including an open-plan kitchen, living and dining space, as well as an outside terrace. These beige lakeside lodges in the heart of the Cotswolds may be luxurious, but design-wise they are the epitome of bland, so Michelle asks the designers to make their mark and really impress her with some design flair.

With individual themes to work to, each designer takes quite a different approach. One goes against their natural instincts and opts for a bold primary colour scheme, drawing inspiration from a classic 80s movie. Another competitor ignores colour completely, hoping that their sophisticated monochrome scheme will appeal to their 'friends' getaway' target market. And for the third lodge the designer picks a nautical theme, using Cotswold stone, wooden panels on the walls and luxury linens on the sofas.

On hand to help Michelle this week is guest judge and queen of dark and moody Abigail Aherne. After a strong showing from all the semi-finalists, Michelle must make a difficult choice as she announces who will be leaving. After a competitive seven weeks, one designers' dream is over, but the final two now have a shot at winning their first commercial contract.