“Small, simple, affordable, beautiful.” That’s what Halifax couple David Black and Heather Scott wanted in a cottage. The busy professionals—she’s a doctor, he’s a professor—purchased 3½ acres of oceanfront just south of Lunenburg, N.S., in 2005, and five years later, figured it was time to build before their teenaged children were launched. The couple wanted a true “retreat”—there’s no Internet, TV, or phone in the off-grid 720 sq. ft. cottage. The design, dubbed “the Shed Retreat” and created by Solterre Design in Halifax, is uncomplicated. The floor, wall, and roof assemblies are built in standard 2x6 stud construction and rest atop an insulated concrete slab that doubles as flooring. The exterior, clad in cedar shingles and medium-density fibre-cement board, boasts an uncluttered aesthetic. It’s a design to suit its purpose.…