Builders nationwide started slightly fewer homes in October but submitted plans for a wave of apartments, a mixed sign for the struggling housing market.

Builders broke ground on a seasonally adjusted annual rate of 628,000 homes last month, down 0.3 percent from September. That’s roughly half the 1.2 million homes that economists say must be built to sustain a healthy housing market.

Building permits, a gauge of future construction, rose nearly 11 percent. The increase was spurred by a 30 percent increase in apartment permits, which reached its highest level in three years.

New-home construction and sales are in the midst of one of the worst years in history. Demand for new homes is weak, and historically low mortgage rates and plunging home prices have done little to help.