Builder confidence continues to grow, rising to its highest level in more than six years.

The National Association of Home Builders/Wells Fargo Housing Market Index hit 40 in September, the best reading since June 2006. It was a fifth consecutive monthly gain.

South Florida builders have been saying for months that business is picking up. GL Homes, Standard Pacific and Toll Brothers, among other companies, have announced new projects or started construction in Broward and Palm Beach counties.

Builders are bullish on sales, future prospects and consumer foot traffic, NAHB Chief Economist David Crowe said in a statement.

But Crowe added that lack of building lots in certain markets is a concern, as is the rising cost of building materials. “Given the fragile nature of the housing and economic recovery, these are significant red flags,” he said.