Ms. Gross said traditional home offices used to have lots of sturdy bookcases and heavy furniture, but some people today have fewer books because of the prevalence of e-readers.
"Some people need to accommodate one to three employees and need a conference space, perhaps with a private entrance, where they can meet clients," Ms. Gross said. "Other people just want a reclusive, private space where they can relax. In some households, a two-person office is required so that each spouse can have a personal desk."