Grand Designs - Season 19 Episode 3 -

Gallery owner Elinor and fitness entrepreneur Born set themselves the task of creating Britain's first hypoallergenic house in a leafy back garden plot in south west London. Driven by the need to alleviate their two young sons' life-threatening allergies, their new part-submerged, shed-inspired home, will be constructed using low toxin materials and deploy cutting-edge filtration systems to clean the air they breathe. Will their innovative new house deliver the benefits Elinor and Born are hoping for?