BUILDER's premier list of the top 100 builders in the country, the BUILDER 100, is set to be released next week. In light of that, we are counting down each day with some facts and figures gleaned from the data. 

Today we examine one of the fastest-growing sectors of the home building industry, active adult housing. Many firms in our list of the Top 200 builders in the country experienced increased closings of these types of units, which are targeted to buyers aged 55 or older.

In fact, active adult sales volume increased by 56 percent last year, from 8,687 in 2012 to 13,565 in 2013. Sixty-six companies reported building this type of housing, including Columbus, Ohio-based M/I Homes and Epcon Communities; Robson Communities in Sun Lakes, Ariz.; and Grand Rapids, Mich.-based Eastbrook Homes,

NEXT WEEK: A look at the fastest growers on our list.

Learn more about markets featured in this article: Columbus, OH.