Within the realm of pre-glazed window units, there are at least four material types used for the frames that can be considered as follows:

Wood and Aluminum-Clad Wood Windows

Clad Wood Windows in Commercial Settings: Ribbon windows made up from individual aluminum clad wood windows. Building: Greensboro Public Library Location: Greensboro, NC Architect: J. Hyatt Hammond and Associates Photo courtesy of Pella

Wood is one of the best thermal performing materials to use in a window frame system with high thermal resistance and excellent insulating ability. As a result, thermal bridging through the frame is reduced compared to other frame materials. The wood used in the manufacture of window units is strong and also has a low coefficient of thermal expansion. But perhaps the most dominating advantage of wood is its aesthetic appeal particularly on interiors. Windows made entirely of wood may be preferred in regions where wood construction prevails and exposed wood finish materials are popular. However, this will require ongoing care and maintenance to protect the wood from environmental or insect damage. Hence, wood windows clad on the exterior with low-maintenance aluminum are more commonly specified, particularly on non-residential projects. This creates a virtually maintenance-free condition on the outside while retaining the appeal of the look of wood on the inside.

The best design applications to use wood windows for include situations where design flexibility is desired since virtually unlimited interior and exterior color options and wood types are available; buildings where the warmth of wood windows will complement other interior woodwork; when low-maintenance interiors and exteriors are important; or in older buildings that require an authentic look. Wood windows can readily be used in singular punched openings or ganged together in horizontal ribbons, vertical stacks, storefronts, or window walls. 

 

 

Clad Wood Windows as Storefronts: Aluminum-clad wood windows and doors used in storefront retail settings with typical elevation and installation details shown. Building: Burlington Apartments Location: Portland, OR Architect: Ankrom Moisan Associated Architects Images courtesy of Pella

Clad Wood Windows Storefront Case Study Phillips Place Location: Charlotte, NC Architect: LS3P Associates LTD.

Image courtesy of Pella When the Charlotte-based architecture firm, LS3P Associates LTD., began designing the Phillips Place project, the team faced two challenges—integrating retail, residential and entertainment spaces within a single development and creating a pedestrian-scaled environment on a site adjacent to a heavily traveled six-lane highway bordered by high-tension power lines. In keeping with the streetscape imagery of the development, storefront windows were deeply recessed in their openings and sit on stone bases. Pre-glazed windows, with boldly articulated aluminum-clad wood fixed frames, create shadow lines inside and out that fit with the architecture.  A more economical solution than aluminum, the aluminum-clad wood windows also offer a variety of exterior frame cladding color options. Interior design flexibility was a major project objective, so the design team specified windows and doors with wood interiors that can be repainted or re-stained for compatibility with any tenant's decor requirements. Window openings varied in size so the windows were fabricated to fit brick and block dimensions without special additional charges. The manufacturer provided technical support from design through construction and beyond, including ongoing custom window and door alterations for tenants.

 

Vinyl windows

Solid vinyl framed windows have gained in popularity in recent years since they are comparatively lightweight, are as thermally efficient as wood, and are often the least expensive option available. Further, vinyl windows do not corrode or rust and the integral homogeneous color does not wear away, blister, crack, peel, or pit. The colors are usually limited to lighter ones such as white or almond since darker colors can promote heat buildup in hot climates that can warp or damage the vinyl. The latest generation of vinyl windows offers darker colors along with deeper frames, more insulating air chambers, optional foam insulation in the frame, triple glazing, and optional blinds or shades between the panes of glass. These enhancements will provide greater structural performance, more design flexibility, and better energy efficiency with total window U-factors as low as 0.15.

Vinyl Windows: Punched openings in a multi-family project using vinyl windows. Building: Prairie Pointe Townhomes Location: Naperville, IL Photo: Wyndham Deerpoint Homes

 

The best applications for using vinyl windows are buildings where individual punched openings are desired, although next generation systems will make it easier to create larger expanses of ganged windows. They are particularly well suited to situations where excellent energy efficiency and low maintenance is needed but budget restrictions require a lower cost product.

Vinyl Windows Case Study Prairie Pointe Townhomes Location: Naperville, IL

Photo: Wyndham Deerpoint Homes Vinyl windows and doors are an option for many non-residential and multi-family projects like Prairie Pointe Townhomes. They can be used in new construction or renovation projects and are available in a wide variety of sizes, styles and frame types. At Prairie Pointe Townhomes, low-maintenance vinyl single-hung windows, sliding windows, fixed windows, and sliding patio doors were included in the building design to provide ample daylight and natural ventilation while offering a competitive price point and outstanding energy efficiency. Superior insulating properties are achieved through a multi-chambered, fully welded frame and sash that reduce sound transmission and heat loss. Strong performance comes from steel-reinforced interlocking sash that helps seal out drafts and improves energy efficiency while providing excellent structural integrity and resistance to wind. Frames are available with an optional integral brickmould for a more traditional aesthetic while sliding patio doors feature a narrow panel sightline that provides a contemporary look that maximizes glass and views to the outside.