Lake Tahoe Case Study: Automating a 40-Foot Bi-Parting Sliding Glass Wall
The brief for this Lake Tahoe home was a glass wall that disappears. Across a 40-foot opening, six sliding panels had to pocket out of sight, three to each side, and leave nothing between the living space and the lake. The panels were heavy, each side had to be able to run on its own, and the finished wall had to read as one uninterrupted plane of glass.
DAS handled the sliding door automation with two motors. Here is how the job came together, and what it shows about planning automation for a very large opening.
The project at a glance
Location: Lake Tahoe, California
Opening: 40 feet
Door system: Sosoares OS six-panel bi-parting sliding system, with matching Sosoares ST fixed windows above, specified by Lucent
Configuration: bi-part pocket, three panels pocketing on each side
Total panel weight: 3,200 pounds
Automation: two DAS Everest motors in a horizontal configuration
Controls: integrated with Lutron
Architect: David Kotzebue Architecture
Builder: Griggs Custom Homes
The challenge: two heavy sides that work alone and together
A bi-parting wall opens from the middle, with panels moving toward each end. On this house, each side carries three heavy panels and roughly half of the 3,200-pound total.
The system had to let each side operate on its own, so one half of the wall could open without the other. When both sides run, they still have to move in step. With that much weight on each side, running the whole wall from a single motor would have compromised reliability and control over the panels.
The solution: one motor for each side
DAS mounted two Everest motors in a horizontal configuration, each placed above the center meeting point where the two sides come together. Each side has its own motor and its own power, so either half can open independently and both halves can run together.
Capacity was not the reason for the second motor. DAS rates the Everest for door systems up to 20,000 pounds, far more than this wall weighs. The second motor is there for control and for independent operation of each side.
The horizontal configuration is one of the mounting options DAS publishes for its larger motors, designed for tight overhead spaces such as the flange of a steel beam above the door. The horizontal configuration drawings show the mounting details, and the Everest motor specifications cover the motor itself.
One motor or two: what decides it
A bi-parting wall can also be run from a single motor. DAS has automated a bi-parting lift and slide of similar weight that way. The trade-off is that both sides always move together. On this house, independent operation of each side mattered, so each side got its own motor.
For a large bi-parting opening, the questions that decide the motor count are:
Does each side need to open on its own, or will the wall always open as a whole?
How much weight does each side carry?
Where can the motors go? Here, the space above the center meeting point had to be planned for them.
A sill you do not see
The entire sill system sits below the finished floor, with only a minimal track visible. When the panels are pocketed, the floor line continues through the opening. The fixed ST windows above share the same profiles as the sliding OS panels below, so the whole elevation reads as one continuous wall of glass.
Lucent specified the door and window systems for this home. Its Lake Tahoe project page covers the Sosoares systems and the concealed sill from the door side.
Controls
The system is integrated with Lutron home automation, so the wall is operated as part of the home's control system. DAS's control options cover the platforms its systems work with.
Planning notes for architects
Decide how the wall will be used. Independent operation of each side is what called for two motors here.
Plan the space above the opening. Both motors sit above the center meeting point, so the head detail has to allow for them.
Coordinate the sill early. A sill concealed below the finished floor is decided in the floor construction, not at installation.
Choose the control platform early. On this job, the wall was tied into Lutron.
For more on specifying automated sliding doors in homes, see our guide to what architects and builders need to know about residential automatic sliding doors.
The result
With both sides open, the 40-foot opening turns the interior into an outdoor pavilion facing the lake. With both sides closed, the wall looks like a single sheet of glass from floor to ceiling. The two motors stay out of sight, and each side of the wall can still be run on its own.
See the project photos and details on the Lake Tahoe project page, and more large-scale work on the DAS projects page.
Frequently asked questions
Can each side of a bi-parting sliding door run on its own?
Yes, when each side has its own motor, as on this project. When one motor drives both sides, the two sides move together.
How heavy a sliding door system can DAS automate?
DAS rates its Everest motor for door systems up to 20,000 pounds. The wall on this project totals 3,200 pounds.
Where do the motors go on a bi-parting wall?
On this project, both motors are mounted in a horizontal configuration above the center meeting point, where the two sides come together.
Can an automated sliding glass wall have a flush sill?
Yes. Here, the sill system sits below the finished floor, with only a minimal track visible.
Planning a large opening?
DAS motors range from single-panel doors to the Everest, its motor for the largest systems. Compare them on the motor systems page, or contact DAS to talk through your opening.
