For investors, "home" is no longer a four-letter word.

The real-estate sector, for the first time in years, is serving as a beacon of relative strength in an otherwise weak economy. Standard & Poor's on Tuesday reported that home prices in its S&P/Case-Shiller 20-city index rose 0.9% in May from the prior month, after adjusting for seasonal trends, and have risen 2.6% since bottoming in January.

Some of the world's smartest investors, including Warren Buffett, are taking notice, placing big bets on a continued recovery in the housing market. Other kinds of real-estate investments—including real-estate investment trusts that own shopping malls, apartment buildings and hospitals—also have been among the best performers this year.

For ordinary investors, the rebound serves as an opportunity to rethink how much of their portfolio should be in real-estate investments—and to participate in the rebirth of a sector they once left for dead.