When Reuben and April came across a ruined 19th-century house amid the tower blocks of Leith, Edinburgh, they saw it as their future home. They had no clear idea of how to restore it, and precious little building experience. Still, they were young and fit (they had met on Reuben’s climbing wall) and they liked a challenge. So they bought the crumbling shell and set about transforming it with their own hands.