Grand Designs revisits Born and Elinor's self build project to see whether the house designed to maiximise air quality helped with their hypoallergenic children
The house used high specs to make sure it maximised air quality(Image credit: Channel 4)
In the latest episode of Grand Designs, a South West London couple set out to build a house like no other, a home designed from the ground up with one purpose: to create a safe, low-allergen environment for their children.
Born, a fitness entrepreneur, and Elinor, a gallery owner, took on a bold self-build project in 2017 after buying a back garden plot tucked down a narrow alley just 200 metres from a hospital.
With their children facing a range of serious allergies – from dust and nuts to wheat and cats – the couple prioritised air quality, natural materials, and low-toxin finishes. The result: a single-storey home with a sunken basement, described as a "beautiful garden shed."
A house designed to provide clean air
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Timber cladding and grey zinc were used as well as low toxin materials(Image credit: Channel 4)
The tiered garden gave the couple's three children the space to play and build their health(Image credit: Channel 4)
The family's top priority was health. The children’s multiple allergies and asthma meant every detail of the build had to support clean indoor air and minimal irritants.
“We knew it might end up looking like a shed,” Born joked, “but we were building it to give our kids a healthy and happy life.”
“We were constantly worried about allergic reactions – even life-threatening ones,” Elinor explained.
The home was built using timber panels and insulation, toxin-conscious materials and solvent-free, eco paints.
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To manage air quality, the self build was fitted with an airtight membrane and a mechanical ventilation heat recovery (MVHR) system enhanced with additional filters. These features help maintain air circulation and reduce airborne allergens – something the family hoped would make a real difference to their daily life.
Construction wasn’t easy. The narrow access to the plot meant diggers couldn’t get through, so the couple had to negotiate access across borrowed land just to start work on the 700m² basement.
Terraced garden that 'doubles the space of the house'
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Each of the three bedrooms connecting to the tiered garden(Image credit: Channel 4)
The underground home was built by digging 700m2 of dirt(Image credit: Channel 4)
Rooflights were used to bring light downstairs(Image credit: Channel 4)
Once past the striking grey zinc roof and clean lines of the home, visitors are welcomed by tiered and sloped gardens full of plants and life that Kevin said "doubles the space of the house".
Each of the three bedrooms opens onto the mature terraced garden, softening the structure with greenery and offering plenty of natural light – a feature that, despite being below ground, creates a surprisingly bright and airy living space.
“It softens and elevates the building,” Kevin McCloud observed, calling the home “a little slice of the Mediterranean.”
Elinor also filled the home with greenery. “We’ve had so much fun with plants,” she said, explaining they even bought an olive tree to celebrate their tenth wedding anniversary. “The power of green space is just phenomenal,” Born added.
The outside space flows into the home, including into the kitchen, where green space plays both a functional and decorative role. Plants are everywhere, even including an olive tree planted to celebrate the couple’s 10-year anniversary.
Family claim the self build improved their health
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Elinor filled the house with as many plants as she could(Image credit: Channel 4)
The bathrooms were also built underground(Image credit: Channel 4)
Seven years after they first began, the family has now fully settled in - and they believe the home has had a positive effect.
The design’s focus on air purity and allergen reduction has given them peace of mind and a space that feels safe.
Their GP noted a reduction in hospital visits, and the home’s low VOC (volatile organic compound) count impressed on inspection. The family also installed air purifiers on lower floors and continued to monitor airflow and environmental quality inside the house.
Elinor described the project as life-changing, emotionally recalling how far their children had come. “I didn’t think it was possible for them to be this healthy,” she said. Born added, “The house loves the kids as much as we love the kids.”
As Kevin McCloud put it, this is more than just another Grand Design, it's a place where “the family can really, really thrive.”
News Editor Joseph has previously written for Today’s Media and Chambers & Partners, focusing on news for conveyancers and industry professionals. Joseph has just started his own self build project, building his own home on his family’s farm with planning permission for a timber frame, three-bedroom house in a one-acre field. The foundation work has already begun and he hopes to have the home built in the next year. Prior to this he renovated his family's home as well as doing several DIY projects, including installing a shower, building sheds, and livestock fences and shelters for the farm’s animals. Outside of homebuilding, Joseph loves rugby and has written for Rugby World, the world’s largest rugby magazine.
