WASHINGTON (AP) _ Despite icy weather in the Northeast and Midwest, construction of new homes jumped 3.8 percent in January to a 12-year high, extending the building boom of 1998 into the new year.

Builders started construction of houses and apartments at a seasonally adjusted annual rate of 1.80 million, the most since December 1986, the Commerce Department said today.

During 1998, they started 1.62 million units, an 11-year high, and economists had expected January would mark the start of a modest decline during 1999.

However, the conditions that drove homes sales and construction in 1998 _ low mortgage rates, plentiful jobs and high stock prices _ continued into 1999.