The San Fernando Valley housing market continued its rebound in February as prices reached a five-year high, according to the Southland Regional Association of Realtors. The median price for a single-family home rose to $422,000, 18.9 percent higher than a year ago and the highest monthly median since August 2008, the Van Nuys-based trade association said. Condo prices rose 30.1 percent to $260,000, the highest February condo median since 2008, though the price fell from a month ago. The increase was driven by higher demand but sales were constrained by a limited supply of homes. A total of 381 homes changed hands last month, just 0.3 percent more than a year ago. The association said there were 1,033 active listings in the Valley at the end of February, down nearly 50 percent from a year ago. That represented just a 1.9-month supply at the current rate of sales, well below the five- to six-month supply considered to be the sign of a healthy market. The lack of listings is primarily driven by the estimated 20 percent of buyers whose homes remain underwater despite the recent rise in prices. More homes are expected to come on the market, though, as homeowners gain more equity in the rising market. Association Chief Executive Jim Link said market demand would be higher but even borrowers with “stellar credit, ample savings and an excellent income” are having difficulty qualifying for mortgages. He urged lenders to return to “fair yet secure” underwriting standards.