With tight inventory stifling a full housing recovery in many markets and foreclosures slowing down, builders are responding by ramping up plans to put new homes on the market, according to an analysis of U.S. Department of Housing and Urban Development data by RealtyTrac. During the first quarter, single-family housing permits  -- approvals given by a local authority to start construction -- were up 27 percent from a year ago, to the highest level since the first quarter of 2008, RealtyTrac reported. The majority of building permits issued in the first quarter -- 64 percent -- were for single-family homes. Houston, Oklahoma City, Austin, El Paso and Fort Worth topped the list of cities where the most single-family building permits were issues, while Texas, Florida, North Carolina, ...