One of those markets: renters looking for more space, both inside and out. Renters should soon see more opportunities to lease brand-new houses specifically built as rentals, while buyers of vacation homes are already flexing their purchasing-power muscles. Currently, only about 6% of all single-family houses are purposefully built as rentals, working out to about 70,000 houses a year. One, Meyers Research, has suggested that big master-planned communities should contain entire neighborhoods of rental houses. Meanwhile, second-home markets, especially those within a four-hour drive of major metro regions, are booming, according to John Burns Real Estate Consulting.