For six years, Ashleigh Kaneski rented a sunny studio in Park Slope, Brooklyn. “I was looking at fixer-uppers, cabins, flipped places,” said Ms. Kaneski, who works as a user-experience designer in Manhattan. I am more of a minimalist and thought, ‘I can’t buy five mattresses.’” So she switched her focus to one-bedroom Brooklyn co-ops, and realized she could afford to …
