Design Considerations

Section Contents:

Product characteristics. Vinyl windows and glass doors offer many of the performance characteristics that specifiers rely on from windows made with traditional materials, with added benefits of low maintenance and durability. Vinyl windows and doors are impervious to rot, rust, corrosion, blistering, flaking and infestation by termites or other insects. Vinyl window and door profiles are typically white, gray, brown or tan, and the uniform color is extruded throughout the product to ensure homogeneous color and lasting color retention. Colors can also be custom-made to meet the needs of individual projects, in which case the color is co-extruded or layered in a thin coat onto the exterior surface. Vinyl windows are manufactured with ultraviolet (UV) inhibitors for improved weathering and stabilizers to protect the frames from cracking, splitting, pitting, peeling or chalking.

Designers accustomed to using traditional window framing will find just as many, if not more, design options with vinyl. Nearly all shapes and styles of windows and glass doors are available with vinyl framing, and vinyl windows can also be customized to meet the size requirements of an individual project or design. Grids or panes for vinyl windows and doors range from standard to custom to enrich the appearance of an architectural or design theme.

Vinyl windows and glass doors perform extremely well in comparison to alternative framing materials in energy and thermal efficiency ratings. Energy-efficient windows mean lower heating and cooling costs for a home or building owner, as well as environmental benefits (see "Environmental Considerations"). Vinyl as a material is not a conductor of heat and cold, and hollow chambers within the frame provide thermal barriers that further block heat transfer.

Technical data. All windows and glass doors must meet minimum requirements for design pressure (windload), structural test pressure (structural load) and water resistance test pressure according to industry standards. The type of building, elevation, wind zone, exposure, terrain and proximity to the coastline, as well as local code requirements, determine the window performance parameters. In general, vinyl windows and glass doors meet the minimum test requirements for the following performance classes:

  • Residential uses, such as in one- or two-family dwellings.
  • Light commercial uses, such as in low-rise multifamily dwellings, low-rise professional offices, libraries and low-rise motels (up to three stories).

Vinyl windows and glass doors are not suitable for some applications such as high-rise office buildings with severe windload resistance requirements. However, vinyl windows and glass doors can be used in most commercial settings, such as industrial buildings, factories, hotels, retail stores, hospitals, schools and other buildings. More technical information is available from the trade associations and manufacturers listed under "Resources" to assist in proper window selection.

Installation. Regardless of the framing material, proper installation is absolutely critical to the optimum performance of a window. Windows that are improperly installed will be less energy efficient and will not provide the quality performance life for which they’re designed. Some of the possible installation mistakes on vinyl windows and doors include creating openings that are too large, improper flashing, improper choice of anchorage or too much space between fasteners. These mistakes can be found in the installation of all types of windows.

To improve the quality of window installations, the American Architectural Manufacturers Association (AAMA) has developed an Installer Training Qualification program for vinyl, wood and aluminum windows and doors. Once installers have taken the training course and passed the final exam, they will be issued AAMA installation certification. This will allow builders to assure their clients that professionals accredited to do the work have installed the windows.

Cost. The installed costs and lifecycle costs of vinyl windows and glass doors are competitive with those of other framing materials, and in most cases vinyl is the most affordable alternative. For example, according to R.S. Means 1999 data, a double-hung solid vinyl window of average quality with insulated glass costs between $166 and $234, depending on size. The same quality of window with wood framing ranges from $199 to $289. In higher-end windows, the differences are even more dramatic. Premium vinyl windows with insulated glass range from $184 to $256, also depending on size. The same quality metal-clad wood window ranges from $224 to $380, while the vinyl-clad wood window ranges from $296 to $665.

Maintenance requirements. Very little maintenance is required with vinyl windows and glass doors. They may require a periodic cleaning with a standard household cleaner but will never need to painted, stained or otherwise treated to maintain their color and strength. Some vinyl window and glass door products allow for painting on the exterior or staining on the interior, and special paints are available for this purpose. The average lifespan of vinyl windows and glass doors varies widely according to the intended application and other factors, but most vinyl window manufacturers offer warranties of 20 to 30 years.