From the National Association of Home Builders: "Construction of attached single-family housing (townhouses) is increasing both in terms of total units and market share. Per second quarter 2012 Census data, total townhouse construction increased significantly in recent months. However, market share remains lower than in past years. "Using a one-year moving average, the market share of townhouses now stands at 11% of all single-family starts, up from 10.4% for the first quarter of 2012. The peak market share of the last two decades for townhouse construction was set during the first quarter of 2008, when it reached 14.6%. This peak was set after a fairly consistent increase in share since the early 1990s.
"Despite the drop in market share during the Great Recession, I expect the share for townhouse construction to increase in coming years. The prospects for townhouses are positive given larger numbers of homebuyers looking for medium-density environments and urban villages that offer walkable environments and other amenities." Full post here and previous predictions here and here.