GLAZED DOOR SYSTEMS

Once a glazing product is large enough to walk through, it is considered a door and may be operable or incorporate fixed panels next to it. The height and width can vary from standard to oversized door dimensions depending on the type of product used. Some of the most preferred door systems are discussed in the following sections.

Swinging Glass Doors

Glazed doors can be incorporated as a single full glass swinging door or combined with others (up to 4 doors in one frame) to create attractive and high-performance glazed openings. The panel thickness of the door can vary depending on the strength needed and the number of layers of glass sought. Common door panel thicknesses are 1 ¾ inches and 2 ¼ inches. The 2 ¼-inch-thick door panels are generally more robust and can accommodate triple glazing more easily. Narrow stile door options are available for some doors as well. These contemporary door panels can have minimal stiles and rails for maximum views.

Photo: RKB Construction Studio; Trejo Photography; courtesy of Loewen Windows and Doors

Swinging glass doors can be used individually or in groupings to create an entry or an overall glazed opening scheme.

Swinging glass doors can be fabricated as aluminum-clad doors or all-wood doors. If they are selected from the same company that produces the other glazing products, then there is a good chance the finishes and appearances will match. The door style can be rectangular, radius-top, or even custom shaped. Configurations include inswing, outswing, right or left-handed, and fixed configurations. Supplemental items such as transoms, side-lites, and screen doors can be readily incorporated to match swinging glass doors.

Bifold Doors

When a transition between indoor and outdoor living is called for in a design, then a large, continuous door opening can be created using bifold glass doors. Essentially bifold doors are made up of multiple door panels that fold open and are stacked on one or both sides of the opening. They are available in configurations of up to 16 panels, which can provide uninterrupted openings of up to 52 feet wide and up to nine or ten feet high. Individual panels can be up to 39 inches wide with custom sizes available. Door panels can fold inward or to the outside so as not to disturb interior furnishings. There is also the option to incorporate a passage swinging door in one section which allows free access without opening the entire set of bifold doors. This is all possible because the weight of the door is typically carried at the head, not the sill, allowing for a smoother transition at the floor.

In terms of options, both wood and aluminum bifold door products are available in a full range of finish colors or wood pre-stains. Wood and metal casings can be provided in some cases as well as optional mid-rails across the panels. Decorative glass work simulated divided lites can be specified where appropriate to a building design. Retractable screens can be added as well to cover the full opening area to maximize ventilation and to protect from insects.

Photo: Hamilton Snowber Architects | Stacy Zarin Goldberg Photography; courtesy of Loewen Windows and Doors

Bi-fold doors create large-scale openings, even in smaller spaces to allow maximum daylight and passage to outdoor areas.

Sliding Patio Doors

A common staple of residential design since the mid-twentieth century has been a sliding patio-style door. They have been popular because they provide a large expanse of glass and access between inside and outside without the problem of door swings interfering with other objects or people. While a two-panel configuration is what most people think of with one sliding operable panel and one fixed, there are other options too. It is common for manufacturers to provide three- and four-panel options with one or two operable panels and the remainder as fixed glass panels. The width of the panels can vary but the common sizes match standard residential door sizes such as 2’-6” or 3’-0”. The panel heights typically match standard door opening heights. This standard dimensioning provides design versatility and significant opportunities for filling a wall with a large opening.

Sliding patio doors typically slide along rollers on the bottom of the door allowing them to open and close readily. Heavy laminated sash construction and tempered safety glass address code and safety concerns. Security is addressed with integral locking hardware and frame construction. Some incorporate an anti-panel-lift device to prevent intrusion as well. Screens can be a sliding screen panel or a retractable screen that rolls up to one side of the door in an enclosed casing.

The design options of sliding patio doors are typical of other standard glazed products in terms of materials, finish, and colors. They can be manufactured in wood, aluminum, or other materials depending on project needs. Hardware is more common to windows than doors in that it is provided with sliding doors as an integral part of the product, subject to variations per different manufacturers. For performance, the full set of choices for glass and frame performance is available. Some manufacturers offer standard 2¼” thick panels for patio doors which allows for a triple-glazed unit, resulting in enhanced energy performance.

Multi-Slide Doors

Multi-slide doors are a cross between sliding patio doors and bifold doors. Their operation is based on sliding panels along a bottom track that may be recessed into the floor in some cases similar to a sliding patio door. Multiple panels can stack out of the way to one or both sides, however, similar to a bifold door system, and create a full-width glazed opening. As such they can create a wider opening than sliding patio doors. They can also be fabricated in taller panels such that they can fill a full eight- or nine-foot wall height with multiple sliding panels.

Photo: Horizon House – Lake Flato Architects; Casey Dunn Photography; courtesy of Loewen Windows and Doors

Multi-slide patio doors offer large-format glazing that can be customized in two-, three-, or four-panel configurations.

As a result of the greater variability in panel sizes, multi-slide doors can provide a cleaner, more elegant design appearance. It also helps that they can incorporate narrower frames around the panels. All of this can help create large, dramatic openings with a fairly seamless transition between indoor and outdoor spaces. The hardware used is different from other types of glass doors to allow smooth operation. Performance can vary based on the manufacturer’s details but at least one provides 2-1/4” thick panels to accommodate triple glazing, add strength, and be more durable than other options.

Due to the larger size and unique nature of multi-slide doors, adding screens deserves some special attention. Sliding screen doors that retract into adjacent jambs is the preferred solution since conventional sliding screens would need to stack and have multiple tracks to accommodate the full width of the opening. The operation of these larger doors can also be made even easier with automated motors and controls and integrated flush handles. Designed to respond to the push of a button, automated multi-slide doors can be operated smoothly yet swiftly while opening and closing. Control is based on either a wireless wall switch or a remote fob that moves the panels as selected. In the event of a power failure, the panels should always still have the capability to be operated manually. Further, automation does not remove the need to physically lock the door for security, which should still be done manually.

Lift-Slide Doors

Some of the largest-sized glass door systems are lift-slide doors. They are based on sill-mounted large panels up to 7 feet wide and 12 feet high allowing for maximum opening size opportunities, although the maximum recommended panel size is 70 square feet of glass. The tracks and hardware in these products are designed to allow the door panels to glide fairly effortlessly by lifting the panels up so they can move freely along the sill track. To close them, they can slide and be lowered to lock down for enhanced weather protection and security. The hardware can also be specified with stainless steel components for corrosion resistance. Thresholds can be selected based on the degree of weather and water resistance required. Flush track options may include integral drainage, creating a safer and seamless transition between interior and exterior spaces.

Photos: Salt Architecture | Dan Cutrona Photography; courtesy of Loewen Windows and Doors

Lift slide doors are among the largest available and offer opportunities for dramatic glazed openings and connections to the outdoors.

The typically high structural integrity of these products combined with different threshold options allow lift-slide doors to be located in areas of high wind and weather exposure where homeowners desire expansive views such as mountains, hillsides, coastlines, or lakefront vistas. Thermal performance can be comparable to other large-format glazing products depending on the materials selected. Dual, triple, and impact glazing are available to accommodate different project requirements. Standard stile and rail construction is an option for wood units with aluminum units also available.

Lift-slide doors are available in multiple types of configurations including straight runs, curved radius patterns, corner opening groupings, and angled layouts. The panels can slide out of the way and be stacked on a jamb side, or the building can have a pocket designed into an adjacent wall to receive the panels and hide them from view when not being used. Retractable screens are the preferred way to allow for maximum ventilation and protection from insects.

CONCLUSION

Architects have a lot of choices when it comes to adding glazed fenestration into residential buildings. While standard windows may be a “go-to” solution, there are plenty of other ways to add large-format glazed products to a successful design. The type of glazing product selected can be based on size and functionality requirements but also on meeting particular design intentions. The performance of any of these products is based on understanding the nature of each type and reviewing the independent test data for structural integrity, water resistance, and energy performance. Working with manufacturers to understand their product offerings, capabilities and limitations can help create very satisfying residential designs that meet the needs of the owners, exceed minimum performance requirements, and stay within the established budget.

Peter J. Arsenault, FAIA, NCARB, LEED AP is a nationally known architect and a prolific author advancing positive acoustical experiences through better building design. www.pjaarch.com, www.linkedin.com/in/pjaarch