The top 10 companies on the most recent Builder 100 strengthened their hold on the new homebuilding market in 2010 by figuring in nearly 25% of all the single- and multifamily homes sold that year, Builder's latest survey finds. That's roughly five percentage points more market share than they had in 2009.

The entire Builder 100 accounts for 43.42% of the 354,000 home closings that took place in 2010. It's the highest share occupied by the top 100 since 2006. One side note: Habitat for Humanity is now the sixth-biggest builder in the U.S., with 6,032 closings in 2010.