Builders in the U.S. have looked over their shoulders for several years, wondering if the threat of a foreign housing invasion was rumor or reality. Would homes start streaming into East and West Coast ports like so many Volvos and Hondas? Would innovations abroad and changing world economics take work away from small and medium-sized builders at home? Experience to date has proven otherwise. Foreign investment in building is increasing rapidly, bringing a welcome infusion of capital to the construction industry. But foreign housing manufacturers remain reluctant to set up U.S.- based factories. A few early attempts that went sour taught foreign manufacturers that differences in land prices, buyers' preferences, and building codes can pose a formidable barrier to housing exports. To