Specifying Considerations for Multi-Panel Systems: Situation, System Type, and Configuration

When thinking about door selection, it is helpful to consider aesthetics, frequency of use, and impact probability. Doors selection is clearly a function of what fits the design of the space.

Multi-panel door systems marry well into a wide range of building types in a number of ways. They can be fully integrated with the building construction to create a seamless and flush appearance so that they seem to disappear altogether when open; in other cases, they can create a large feature in a facade by allowing for a distinctly defined opening. Multi-panel doors can be harnessed to further the overall building design and enhance or to define a particular aesthetic.

A vital balancing act during initial design, which will impact energy outcomes, is determining how much fenestration to use as a percentage of the overall wall area of a building. Many energy codes prefer to see total window and door space at or less than 40 percent of total wall space. Depending on exposure and climate zone, a large amount of glass on western- and south-facing walls can expose the building to unnecessary solar heat gain. However, using glass on a south-facing facade in a heating-dominant climate can yield passive solar heat gain during the winter when the sun is low in the sky, offsetting mechanical heating. Simple energy modeling of different scenarios during the earliest stages of design aids in selecting the most appropriate balance between walls, doors, and windows.

Visually, multi-panel door system sizes and proportions may be chosen to match the complement of single doors and windows in the building. Creating a unified design scheme for fenestration will help shape finish, operation, and profile options. Depending on the manufacturer, stile and rail sizes for multi-panel systems can be ordered to exactly match other doors in the facade. Once high-level energy and aesthetic concerns are addressed, examining the daily operation of the door helps dictate type and operation. High-traffic areas and openings subject to abuse require doors of heavy-duty construction. Frequency of use is classified as high, moderate, or low, depending on the door’s location in the building and the number of times per day the door will be used. For example, most building entrances are classified as high-frequency openings. Doors that normally remain in the open or closed positions are considered low-frequency openings. If a multi-panel door system will serve as the main entrance to a retail store or restaurant, and will be opened and closed throughout the day, with heavy foot traffic, a highly durable door frame, an easy-to-use hardware system, and a durable threshold need to be considered.

Impact probability also is classified as high, moderate, or low. Doors subject to high impact are often the very same doors with a high frequency of use, but not always. Referring to ANSI/SDI A250.8 may be helpful in guiding selection.

Multi-panel door systems are often selected with a design intent to embrace natural surroundings and exterior conditions. With this in mind, determine the optimal number of panels to maximize the amount of glass and natural daylighting. Individual sliding panels typically have a much wider maximum width than folding panels, meaning more glass and less frame disruption, whether the door is open or closed. However, folding systems are usually capable of spanning a greater width overall, a factor if the goal is to open up a maximum amount of wall space when the door system is in use.

Operational considerations involve studying the different types of door operations available and their swing or stack directions when designing a space. Key questions include how the space will be utilized, including furnishings and traffic flow, and determining the preferred location of door panels when fully open. Pinpointing where and how the system will be operated for daily use can also lend clues to preferred operation. If some drywall will feature on an elevation, a pocketing multi-slide door may be a great choice. A folding door might be best if the client wishes to use a multi-panel door in different configurations. When a homeowner requests a multi-panel door to open onto a small patio space, a multi-slide could be ideal, as it will avoid taking up valuable area whether open or closed.

Multi-panel door system type and configuration are ultimately a function of the design of home and space.

DESAI RESIDENCE, BUILD LLC

We’ve been using certain products for the last couple of years that allow entire rooms to gather generous amounts of natural light throughout the seasons, and when the weather turns favorable, these same systems allow indoor rooms to fully open up to the outdoors. It wouldn’t do these products justice to simply call them windows or glass doors. Rather, these are glass walls capable of opening up, or in some scenarios, nearly disappearing altogether.

Here in the Pacific Northwest, operable glass walls make a significant lifestyle difference. The low angle of the sun, combined with the short days of winter and fall, leaves most of us Seattleites yearning for more natural light. One of the first strategies to fight this dreary problem is designing floor-to-ceiling glazing into our projects. This ensures that the interiors are taking advantage of every bit of daylight they can and reducing reliance on lighting. In the summer and spring, the temperate climate and lack of humidity makes walls nearly obsolete (save for keeping the bugs out). Designing transparent walls that can easily slide open creates a strong relationship between inside and outside, allows for exterior spaces to become outdoor rooms, and provides excellent natural cooling for the interiors. It’s a win-win scenario.

Photo courtesy of Build LLC

The Desai residence

Accordion systems are also an excellent consideration for operable glass walls. Because the door panels fold and slide together, the panels take up less space in their open position, thereby allowing a larger opening, as in the Desai residence (above). This application uses a five-panel bronze anodized aluminum panel accordion system, where each panel is approximately 3 feet 3 inches wide by 8 feet 10 inches tall. The clear opening of this composition is approximately 16 feet 6 inches minus about 18 inches for the doors in their open configuration. Like the sliders, the accordion system offers a range of permeability. The end panel works just like a single passage door, and the entire assembly can be folded up as much or as little as desired.