Builders are hammering away at more new houses than at any time since before last decade’s foreclosure crisis, and the construction boom is driving up lumber prices. Lumber futures are up more than a third from lows reached last June. …In December, U.S. housing starts surpassed a seasonally adjusted annual rate of 1.6 million. …Residential building permits are being issued at the highest rate since 2007. Mild winter weather has extended the building season in much of the country. …Random Lengths ended January with a seventh consecutive weekly gain, to $388 per thousand board feet. …On Monday, lumber prices declined after the Canadian government said U.S. trade officials had indicated that tariffs on exports into the U.S could be significantly reduced later this year/. Marty Juravsky, finance chief Interfor, told a gathering of investors… that lumber prices should be $50 higher given supplies and the booming housing market. [a WSJ subscription is required to access the full story]