In this show, a couple in Sheffield want a modern extension on their 1930s home, but they're told they must make some compromises; and a couple of architects are also forced to change their plans.The Singhs in Coventry have totally gutted and rebuilt their period home, and they're delighted with the results.All three families believe that ultimately their extensions will substantially increase the value of their properties.Three ambitious projects, three very different households, and three different sized budgets. So who will get planning permission? And who will get the most additional space for their money?