WASHINGTON – U.S. builders started work on more single-family homes in May and requested the most permits to build homes and apartments in three and a half years. The increase suggests the housing market is slowly recovering even as other areas of the economy have weakened.

The Commerce Department said Tuesday that builders broke ground on 3.2 percent more single-family homes in May, the third straight monthly increase.

Overall housing starts fell 4.8 percent last month to a seasonally adjusted annual rate of 708,000. But that was entirely because of a 21.3 percent plunge in apartment construction, which can be volatile from month to month.