Investing.com -- Housing starts in September fell 9% on an unadjusted basis to a seasonally adjusted annual rate of 1,221,000 units, according to Truist. The figure came in below the consensus estimate of 1,305,000 units.

The shortfall appeared to stem entirely from the multi-family segment, which dropped 28% year-over-year. Single-family housing starts showed stronger performance, rising roughly 2% compared to the same period last year on an unadjusted basis.

The South and Midwest regions led in performance, with increases of 7% and 1% respectively. The Northeast and West both recorded declines.

Total permits on an unadjusted basis decreased about 4% year-over-year. The decline came from a 6% year-over-year drop in single-family permitting, ending several months of modest gains through the summer. Multi-family permits remained roughly flat compared to the prior year.

Total completions fell about 14% year-over-year. Both single-family and multi-family completions were weak in September, declining 11% and 21% year-over-year respectively.

The housing starts data affects building products companies such as Builders FirstSource (NYSE: BLDR) and James Hardie (NYSE: JHX), construction materials companies including CRH (NYSE: CRH), Vulcan Materials (NYSE: VMC), and Martin Marietta Materials (NYSE: MLM), and homebuilders such as D.R. Horton (NYSE: DHI), Lennar (NYSE: LEN), PulteGroup (NYSE: PHM), NVR (NYSE: NVR), Toll Brothers (NYSE: TOL), Meritage (NYSE: MTH), and KB Home (NYSE: KBH). Completion numbers impact Installed Building Products (NYSE: IBP).