Hollin Hills Windows
 
What every Hollin Hiller should know about replacement windows.

Hollin Hills houses were originally built with single pane glass in all of the windows.  Those of us that live in the houses know from our heating and cooling bills this is neither energy efficient, nor comfortable.  Not only is the single pane glass energy inefficient, but humidity condenses on the interior of cold glass, often covering the window with condensation, and causing water to pool on window sills.  In extremely cold weather, the condensation on the interior face of the window freezes, resulting in a layer of ice on the inside of the window.  Many find this “Dr. Zhivago” effect to be uncomfortable. The solution is to change the single pane glass to insulated glass, often referred to by the brand name Thermopane®.  Insulated glass leads to a more comfortable room, both in summer and winter.  In addition to lowering energy bills it also reduces, and in many cases eliminates, the condensation problem.

left side-single pane glass with frozen interior condensation right side, new insulated glass, no condensation. Feb 2008 Click image for larger view.

R-value and insulated glass
R-value is the measure of the insulating value of a material.  A single pane of plain glass has an R-value of less than one.  A double pane window with plain glass has an R-value of about two.  A double pane window with low-e, argon filled glass has an R-value of around 3.5.  Low-e glass has one interior surface covered with an invisible film of metal.  This layer acts as a heat reflector and reduces the amount of heat that flows through the glass.  Argon glass in the void between the two panes further increases the R-value of the glass.  The additional cost for low-e and argon is only a few dollars per window, and adds nothing to the installation cost.  An additional benefit of the low-e coating is that it helps filter UV light, which is the primary cause of fading in furniture.  Any new windows should be low-e, argon glass.  As it is difficult to identify low-e, argon glass by looking at it, it is vital that the homeowner knows what he or she is getting before signing a contract. 

Spacers

The two panes of glass in an insulated window are separated around the edge by a spacer that seals the space between the two panes of glass, and acts to separate the two panes to create the void between them.  The spacer needs to provide at least a half inch space between the panes.  A smaller space provides less insulating value.  Originally the spacers were made out of metal, either stainless steel or aluminum.  However, as metal is an excellent conductor of heat, these metal spacers reduce the insulating efficiency of the window by increasing the conductivity around the edges.  Insulated glass windows with metal spacers often have condensation form around the perimeter of the window because the inside surface of the glass is so much colder at the edges than in the center of the glass.  That constant dampness can lead to peeling paint and mold on the interior of the sill.

Example of window with foam spacer. A premium paint job by Fina Construction makes windows sills look like new.  Click image for larger view.

Metal spacers can reduce the overall R-value of the window by up to 20%.  Windows with this obsolete, inefficient, technology should be avoided whenever possible.  Metal spacers may be identified by their shiny chrome color.  The current technology uses a foam spacer that is far more insulating than the metal spacer.  An added benefit of the foam is that it makes the seal at the edge of the windows flexible, rather than rigid, and therefore less likely to fail with the repeated expansion and contraction of the glass caused by daily temperature changes.  The foam spacers tend to be grey or dark grey.  Most, if not all, of our competitors are still using the obsolete, inefficient metal spacers. Fina Construction uses foam spacers wherever possible.  (click for more info on foam spacer technology)

Warranty
Insulated glass manufacturers provide different levels of warranty, including no warranty at all.  It is important to have the warranty period stipulated in your contract.  We offer a blanket warranty on our glass and installation for a period of five years. The maunufacturer we use warrants the glass against seal failure for fifty years. Hollin Hills houses tend to move around due to soil conditions.  Warranties will not cover damage to the glass caused by shifting of the house.

Triple pane 
The next step up from double pane glass is triple pane.  This is an insulated unit that has a thin layer of glass centered between the two outer layers. Triple pane glass with a low-e coating on two of the surfaces and argon gas in both voids brings the unit R-value up to about 5. The downside of the double low-e glass is that the greenish tint and the reduction in transmission in visible light become noticeable.  In terms of maximizing R-value per dollar, the triple pane, double low-e unit offers the best value.

Glass thickness
The building code mandates a minimum thickness of glass for any given size, but it is a minimum. The larger the pane is, the thicker it must be to not deflect or break.  The minimum thickness I recommend is ⅛ inch glass (double strength), and 3/16” or ¼” glass may be required in larger windows.

Operable windows
The discussion above focuses on fixed glass, but many of the windows in Hollin Hills houses are operable.  The original metal casements, sliders, and awnings not only have a low R-value, but as they rarely close tightly, there is actual air infiltration around the window.  The advantage to the old operable windows is that they have a fairly small frame and thus don’t interrupt the clean line of the Hollin Hills window module.  Unfortunately, from an esthetic standpoint, these windows are no longer available.  The typical replacement operable window these days that is approved by the DRC is a wood awning or casement, usually with an exterior cladding of vinyl or aluminum.  This cladding obviates the need for paint and prevents rot.

Example of a custom operable window.   Click image for larger view.

While there are a few stock window sizes that fit Hollin Hills openings, usually it is necessary to have the window custom made to fit the opening exactly.  This minimizes the amount of window trim necessary, and makes the window fit with the line of the Hollin Hills window module as closely as possible.  A window that is even an inch too small for the opening ends up looking heavy and out of place.   Our competitors often use stock sizes, rather then a custom size that fits, so often in their installations unsightly heavy trim is tacked on around the operable windows

Exterior trim
Hollin Hills houses were originally built with a metal flashing over the top of the window frame to divert rain water from the top of the window frame, and keep it from penetrating into the house, or rotting the top of the frame.  In areas that are exposed to the weather, and when new trim is added, new flashing needs to be added to prevent the water from running down between the frame and the new trim.  We have developed custom flashing details over the years for the different models of houses and window conditions.  Few, if any, of our competitors bother with this important detail.

Frame repairs
Often the wood framework in which the glass is set is has water damage, particularly in the flat roof model houses.  As the window frames support the roof, knowing how to replace the frames safely is important.  We specialize in this type of repair. 

Lead Paint

New Federal regulations designed to reduce lead paint hazard to homeowner and their families require all window replacement to be carried out by an EPA certified contractor. Fina Construction is fully certified, and our crews fully trained for EPA lead paint compliance.  Click here for more lead paint information.

Insurance
Removing and installing glass is a fairly hazardous endeavor.  Homeowners should confirm that their contractor carries liability and workers compensation insurance.  Otherwise, if anyone is injured, the homeowner may end up being liable for medical bills and disability of injured workers.  Legitimate contractors can provide a certificate of insurance. Fina Construction is fully licensed and insured. 

Design review
The Hollin Hills design review guidelines require approval for replacement windows.  If the windows are done right, DRC approval is typically fairly routine.  The problems start with contractors who are unfamiliar with the Hollin Hills design esthetic and try to install what they have to sell, rather than what will fit, both physically and esthetically.  Since Hollin Hills is so architecturally unique, and the windows are such an important visual feature of the houses, it is vital that window replacement be done in an architecturally mindful manner. (link to DRC)

 

Fina Construction has been specializing in Hollin Hills for over twenty years and we have replaced thousands of windows.  To see what some of our customers have to say about our window replacement, click here.

Questions and comments are welcome at 703-718-0804 or email us for more information.



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