A perfect storm of building regulations, smaller lot sizes, and HOA restrictions creates worries and additional costs for homeowners
By Deborah Goonan, Independent American Communities
In the past year, several local television news stations have highlighted consumer headaches caused by energy efficient windows.
According to several reports, including an official educational statement written for National Association of Home Builders (NAHB), the intense heat reflected from Low-E windows are causing warping and blistering of vinyl siding on neighboring properties.
Low-E windows reflect heat
Low-E windows are manufactured with two panes of glass separated by air, or, sometimes, argon gas. The glass is coated with a special “low-emissivity” film that allows light to pass through the glass, but, at the same time, prevents heat transfer through the window.
That’s how Low-E windows save energy: in summer, the windows reflect the sun’s heat away from the house, keeping the interior of the home cooler. Then in winter, Low-E windows, especially those with argon gas between the double panes of glass, prevent heat loss by reflecting heat back into the home.
Sounds like a great way to save money on heating and cooling your home, right?
But there’s an unintended consequence to heat reflection. The drastic temperature difference between air inside and outside a home creates uneven air pressure on each side of the window. That can cause one or both of the panes of glass to bow slightly, creating a magnifying glass effect that concentrates a beam of heat and light onto adjacent surfaces.
Research has found that those concentrated reflection beams can reach more than 200 degrees Fahrenheit.
Standard vinyl siding begins to melt at temperatures above 165 degrees F, prompting thousands of reports of warped siding over the past decade. Other consumers have complained of damage to plastic trim on their vehicles.
Even more frightening, WABC7 (New York) and WRAL (North Carolina) documented instances of fire caused by heat generated from intense reflections of sunlight from Low-E windows. As you’ll see in the videos linked below, some homeowners have reported burns in the cushions of their outdoor furniture. In another case, a homeowner says that heat from low-E glass reflections triggered a fire in a layer of wood mulch in her yard. And a New York Fire Chief has expressed his safety concerns as well.
No one willing to take responsibility
NAHB dismisses the idea that heat reflections from Low-E windows can cause a fire, stating, in its report:
…there have been no reported instances of fires, and the temperature readings for focused reflected sunlight (less than 250 degrees F.) are well below the combustion temperature of wood – 451 degrees Fahrenheit. The possibility that reflected sunlight poses a fire hazard has been investigated in several states, including Massachusetts and North Carolina, but ultimately discounted.
Likewise, the window manufacturing industry contends there are “other contributing factors” causing damage to vinyl siding or burning of wood or other materials in the path of heat reflection beams.
The vinyl siding industry admits its standard product begins to warp and break down at 165 degrees F. A few manufacturers offer a more heat-resistant CPVC product (up to 220 degrees F), but the more durable material increases the cost of production, making it an impractical alternative for most home builders.
Vinyl siding manufacturers have also adjusted their warranties to exclude claims for damage caused by heat sources, including Low-E window refelctions.
That means homeowners end up paying to replace warped vinyl siding or other property damaged by their neighbors’ Low-E windows.
Building codes play a role
Local building codes often mandate Low-E windows or argon filled windows for new construction, as well as approved permits for window replacements. Many municipalities have been doing so for years. Therefore, the use of Low-E has become widespread in the past two decades.
In this case, local governments cite energy savings as the reason for the mandate. But one can also argue that local mandates of a specific type of window results in an artificially high demand that benefits certain manufacturers and suppliers.
And when local government officials also mandate or heavily promote housing density, decreasing space between individual homes, their policy increases the likelihood that reflective heat from Low-E windows will come in contact with a neighbor’s vinyl siding.
Can the hazards and property damage be prevented?
Some window manufacturers produce windows with capillary tubes — small air passages that help to equalize air pressure. This feature appears to prevent the window from producing heat reflection beams. Capillary tubes are mandated by code for homes at high elevation levels, mostly in western states. But, in most states, capillary tubes are not required, even though the added cost to include them is nominal.
Manufacturers, home builders, and window installation companies are not inclined to offer free replacement of Low-E windows. And most homeowners aren’t willing to absorb the cost of replacement either.
At this point, it appears that the most practical way to prevent property damage is by inserting a window screen or installing an awning over a Low-E window. Experts believe either option prevents the reflection of concentrated, hot beams of light.
However, if your neighbor won’t cooperate by adding screens or awnings, you’re usually on your own to figure out another solution.
That often involves screening out heat reflections with carefully placed landscape plants or a non-combustible fence, both of which can be expensive to install.
Quite commonly, a homeowners,’ condominium, or cooperative association is responsible for maintenance and repair of exterior surfaces, including siding. And since home builders and manufacturers are unwilling to replace damaged siding, the repair work becomes an added expense for all homeowner members of the HOA.
Unfortunately, a homeowner often has little control over if or when the association will make necessary repairs. The HOA may delay taking action until it can figure out how to ensure that homeowners take steps to prevent future damage. Or your HOA board may waste time seeking ways to recover the association’s costs before beginning the project.
If the HOA is not responsible for providing exterior maintenance of homes, the matter becomes a dispute between two neighbors, with most HOAs avoiding direct involvement.
In other words, the problem is not easily resolved in favor of homeowners.
Meanwhile, window and vinyl siding manufacturers, as well as home builders, reap millions of dollars in profits with virtually no accountability to housing consumers.
12 additional homeowners report melting issues due to Low-E windows
Posted 6:45 p.m. July 4, 2018
RALEIGH, N.C. — WRAL Investigates recently looked into the issue of Low-E windows and how they are melting home siding and starting fires. Now, other viewers who saw the story have additional complaints and concerns.
In May, WRAL spoke with a Massachusetts-based forensic scientist who is looking into why Low-E, or energy efficient, windows are starting fires.
So far, no much data exists, but Curt Freedman wants to spur change.
Freedman said, based on the overall safety and health concerns, he believes Low-E windows are the next asbestos.
7 On Your Side: Energy efficient windows posing fire hazard for some homeowners
By Nina Pineda
Monday, July 31, 2017
HASTINGS-ON-HUDSON, New York (WABC) — Billions of low emission (Low E) windows are installed each year. But, some homeowners are saying these energy efficient windows are causing a significant fire hazard.
One homeowner’s vinyl siding dimpled, then blistered and warped into waves. But the homeowners could not figure out why it was happening until their research turned up some scary video.
The problem? Energy efficient or “Low E” windows that reflect the rays of the sun like a magnifying glass.
In California, a homeowner says her Low E windows reflected the sun, burning and blackening her patio furniture cushions.
In North Carolina, a homeowner blamed a neighbor’s windows for igniting dried mulch. Her surveillance video capture creeping flames that almost engulf a propane tank. Luckily landscapers stamped it out.
Do Your Windows Have the Power to Melt the House Next Door? (Houselogic.com)
Sunlight Reflected from Double-Paned Low-E Windows, and Damage to Vinyl Siding and Other Materials (National Association of Home Builders)