How to Select Replacement Windows

• By David H. Martin
• 01/01/00

As one might imagine, with the major capital investment required to replace all or most of the windows in an institutional building, the window selection process is neither simple nor swift, as there are many issues that need to be addressed.

Tim Davis of Aluminum Resources, Inc., of Cincinnati, has found that most window replacement projects must address one or more of four typical issues. “Energy, maintenance, security and vandalism are key concerns with many officials,” he says.

To help ease the replacement process, Davis developed a Window Selection Guide (see box on p. 43) for administrators. He recommends that the guide be used as “talking points” for an initial discussion with all concerned parties in the window selection process.

In addition, here are 11 points administrators should be aware of when replacing windows.

1. Project timeline: Davis says the selection process can take two or more years from the time administrators are first aware of a window problem. And, often, the window replacement program is part of a larger renovation package that might require even more time while funding issues are resolved. However, the good news is this, he says: “The actual window replacement component can be completed in four to six months from go-ahead to installation.”

2. Project responsibilities: Your local commercial window dealer (like Aluminum Resources, which represents Graham Architectural Products) is the primary contact representing the manufacturer and has the responsibility of furnishing and installing the windows. The manufacturer provides appropriate warranties for all products provided.

3. Developing requirements: Bill Wilder, Graham technical services manager, agrees with Davis that a “shopping list” of requirements must be created and prioritized. Sometimes compromises are necessary in the window selection process. “While the architect or administrators may share a strong desire to ‘replicate what was there,’ often their concerns for cost control or enhanced thermal performance will evolve to other solutions,” he says.

4. Keep original frames: Whenever possible, to facilitate window replacement and minimize construction costs, it pays to avoid removing the original frames. Commercial replacement systems often include historically accurate panning and trim systems to cover up the pre-existing frame and minimize the tear-out process.

5. Energy payback: Sometimes, says Wilder, an architect will ask that an “estimated energy payback” be calculated to justify costly thermal glazing upgrades. You, too, may want to consider asking for this.

6. Aesthetics vs. practicality: Sometimes aesthetic considerations give way to practical limitations. It may be necessary to replace True Divided Light (TDL: windows with small, individual panes) with windows with applied muntins that create the illusion of TDL, while offering far better thermal performance in a modern insulating glass (double pane) system. While the egress code might dictate the use of one sliding window in place of a double-hung, sometimes the slider can be “disguised” to look much the same as the double-hungs surrounding it!

7. Performance considerations: These are not limited to thermal issues. Air and water infiltration ratings and wind deflection requirements are also factored in. Tinted glass may be used to control heat gain in warm climates. Break-resistant polycarbonate may be chosen for security and to prevent vandalism. Tempered glass may be chosen for the same reasons.

8. Hardware considerations: Local egress codes may dictate one operating system over another, in order to facilitate rapid evacuation in the event of fire. Hardware decisions can also be dictated by local codes limiting travel of the bottom sash. Pole hardware may be necessary for the upper sash to permit effective ventilation. Window washing hardware may also be required.

9. Projecting windows: While double-hung and sliding windows offer excellent ventilation, projecting windows may provide a feeling of security in classrooms with computers, where theft is of major concern. On the other hand, some administrators rule out projecting windows because of the potential for bumped heads and other injuries that might occur outside of the building.

10. Double-hung windows: Ease of operation may be a closely defined issue with double-hung windows, advises Wilder. “Some administrators specify that the sash must operate with no more than 20 to 45 lbs. of force.”

11. Installation strategy: In an ideal world, all windows would be replaced in the slow summer months when classrooms are empty. In the real world, windows are often installed only at night or on weekends. Wilder reports that some contracts require that window installation in any one room “must be completed within 24 hours,” as partially completed installations raise questions of security as well as additional disruption.

David Martin is a freelance writer and partner with Lenzi Martin Communications, Oak Park, Ill.