Sun reflecting off windows melts siding in Woodbury

Two years ago, Rick and Annette McWane were about to close on a new home in Woodbury when they noticed that one side of the house looked as though it had had a bad facelift. They decided to buy it anyway after the builder promised to fix the patch of vinyl siding.

They soon realized that the problem wasn't going away. Their hilltop location, a feature they loved, had also put them in the middle of a strange physics experiment. Sunlight shining on their neighbor's energy-efficient windows reflected onto their house like a magnifying glass. The intense rays, which can reach temperatures above 180 degrees, have caused the McWane's siding to warp and wrinkle.

"It started melting within a few weeks," Annette McWane said. "It even melted that winter."

Over the past two years, the builder, Pulte Homes Inc., has replaced the siding for McWane and several of her neighbors. Then the melting starts anew. While the window and siding manufacturers squabble about who is to blame, homeowners are left wondering if there will ever be a fix.

Kerry Haglund, a research fellow with the University of Minnesota's Center for Sustainable Building Research, said the high temperatures could be caused by several factors within the window manufacturing process, including a coating that is meant to increase the reflection. Window industry experts are working on adjustments that could be a solution, she said.

Vinyl siding manufacturers said they have heard of isolated cases across the country, but they don't think the problem is widespread.

Eric Younan, a spokesman for Pulte Homes, said the Michigan company sees the melted siding mostly in northern states where homes are built with energy-efficient windows that use "low-emittance" coating. He said Pulte is meeting with a new glass maker soon, and it would take two weeks to manufacture it.

"Once we receive the glass, we will ... replace the glass and the affected siding on the home next door," Younan wrote in an e-mail. "Again, we will need time to determine if this is a permanent fix."

No easy fix on the market

While the McWane home has suffered the worst damage, about 25 of 109 homes in the Fairway Meadows development have at least some sun-warped siding, according to records of the homeowners' association. Pulte has replaced the siding multiple times on some homes.

This year, Annette McWane didn't even ask Pulte to bother putting on new vinyl. She's more worried about how she would explain the problem to a potential buyer.

"I have a feeling that I would have a hard time selling, especially since they've replaced it twice and it's still melting," said McWane, who is not yet trying to sell the house.

In August, Jerry Zick, Pulte Homes of Minnesota's general manager of special operations, wrote a letter to the McWanes saying that the builder will provide a letter to any future buyer stating that Pulte is "working on this issue."

"We have tried many different formulas with the siding manufacturer along with a different brand in their line of siding to no avail," he wrote.

Jery Huntley, president of the Washington-based Vinyl Siding Institute, said reflection from some energy-efficient windows can affect other surfaces, including the paint on cars. Her organization has worked with both siding and window manufacturers to look for solutions, but so far there aren't any products on the market that will create an easy fix. She said homeowners should work with their builders to solve the problem with window shades, awnings or landscaping.

"This heat clearly exceeds normally natural conditions that vinyl siding and other building materials are normally expected to withstand," she said. "All we can do is suggest ways to avoid it and encourage more research."

The McWanes sometimes wish they hadn't bought the house on the hill.

"It was brand new so there shouldn't be anything wrong with it," Annette McWane said. "I guess you can't blame anybody, but Pulte just needs to keep working on it."