Jim Lucas and Jennifer Mole, and their two daughters, Indie, 8, left, and Tilly, 6, in their home in Coldingham, Scotland. COLDINGHAM, Scotland — The surprising thing about visiting Sunnybank, a light-drenched home in Coldingham, a picturesque village near Scotland’s southeast coastline, is that its entrance is barely visible. That detail, admits Jim Lucas, one of the home’s owners, was quite deliberate. Mr. Lucas wanted the stone facade facing the street to lend an...