To really relax in a space, people need to feel in control of it, that no one can intrude visually or acoustically without their permission—in other words, no one can see or hear them and they can’t see or hear anyone else clearly either. Some private territories are permanent or at least indefinitely owned (even the surliest teenager will [probably] eventually leave home) and others are just ours for an hour or an afternoon, but whatever the case, we need…