Kevin, Zac and Damion profile five homes that are testbeds for architectural ideas, pushing the boundaries for residential design: a cool, concealed house built from glass and concrete; an uber-creative Wallace and Gromit-style house in Edinburgh squeezed onto a disused plot; a gorgeous, low-slung modern home in Cumbria camouflaged with stone; an experimental extension in London with a Japanese flavour; and an elegant house in Buckinghamshire that combines sustainability with glamour. Kevin then reveals which one has made it onto the shortlist and is in with a chance of winning House of the Year 2016.