As Hurricane Irene threatened much of the U.S. East Coast Friday, Wells Fargo home-building analyst Adam Rudiger assessed the impact the storm could have on the big public builders. His conclusion: The most exposed were NVR (NYSE:NVR) and Toll Brothers (NYSE:TOL).

In a research alert to investors, Rudiger said all builders who operate in areas affected by the storm would likely face declines in traffic this weekend and perhaps physical damage to inventory. "Hurricane Irene will have a negative impact on orders, in our view, as weekends tend to be higher traffic days for builders and poor weather is likely to deter prospective buyers," he wrote. "That said, August is not traditionally peak selling season, although we do note, as measured by non-seasonally adjusted new home sales, over the last 10 years, August was the seventh most important month of the year."

Regarding physical damage, Rudiger said the greatest impact could come via construction delays made necessary by efforts to repair any damage that might occur. "With high winds expected in many coastal markets, any unfinished inventory could be vulnerable to wind damage or destruction. We believe builders have insurance, however, so the financial risk should not be significant, in our view. That said, if any material damage does surface, it could have the adverse effect of delaying completion and could push closings out, thereby delaying revenues."

Rudiger estimated that among the company's in his coverage universe, the most exposed would be NVR, which he said had 62% of its inventory in areas expected to be hit by the storm. Toll Brothers was next at 42%, followed by Hovnanian (NYSE:HOV) at 32%, and Beazer (NYSE:BZH) at 28%. On the lower end of exposure were KB Home (NYSE:KBH), with 9% of inventory in harm's way, and Lennar (NYSE:LEN), with 15%. Meritage Homes (NYSE:MTH), he said, was least exposed with no communities open in markets likely to face the storm.