Malibu Crest, a 2019 remodeling of a 1949 International Style home, was a vital undertaking by the architecture firm Studio Bracket that aimed to expand the structure’s square footage and panoramic views of Malibu while retaining over 50% of the home’s original walls. The project was ultimately successful, not only in its refurbishment of the interior rooms and reconfiguration of the space, but in its enlargement of the windows to truly capture views of the surrounding lagoon and mountains. This expansion of the view was done in part through an open corner window scheme and floor-to-ceiling glass, manufactured by Western Window Systems. The uninterrupted glass walls afforded by this open corner technology is one of the most effective ways that architects can open an interior space to the stunning vistas of a natural environment. Yet an even more striking configuration increasingly being employed by residential architects is that of the open corner sliding glass door – a system that can even more completely open an interior space to the unobstructed outdoors. Below, we discuss this technology in more detail, alongside several examples of projects using the open corner glass door.
The design and materials of open corner windows and doors vary depending on the manufacturer. Western Window Systems, the manufacturer in charge of the windows of Malibu Crest, uses tempered glass as a default for open corner products due to its greater strength than regular glass. At the open corner of a window, manufacturers will typically simply butt the two panes of glass together. In this case, however, the two sheets of insulated glass are joined in a 90-degree wedge shape, creating a seamless connection, with silicon inserted between the two to seal the unit. For their open corner multi-slide doors, the frames and design are equally dramatic: with a unique extrusion attached to the end of one panel, the adjacent panel sliding in at a 90-degree angle simply nestles in smoothly.
The energy efficiency of these open corner systems are nearly identical to those of regular windows and glass doors, making their primary advantage the added aesthetic value. Open corner windows and doors, by eliminating a corner structural frame or wall, have the effect of blurring the boundaries between interior and exterior, making walls feel less like walls and more like a portal into the outdoors. Flattening the view into what feels like a 3D landscape painting spanning two adjacent walls, open corner windows visually bring light and nature into a home or room even while maintaining the physical barrier between the two. When opened, open corner sliding glass doors conversely remove the barrier between interior and exterior completely, an effect accentuated by the lack of a corner frame communicating the structural boundaries of the home. Instead, any exterior space and the internal room become one, making open corner glass doors an especially useful product for homes with outdoor amenities such as outdoor grills, dining areas, or pools.
One stunning example is the expansive home shown in the images above, located in Scottsdale, Arizona and designed by Jessica Hutchison-Rough of Urban Design Associates. Ltd. Employing several open corner glass windows, the home also features an open corner sliding glass door merging the interior kitchen and dining space with an additional dining area outdoors. Through this open corner, the dining space seems to be naturally enlarged rather than artificially extended into a sequestered patio outside. As a result, the space feels much larger, much more open, and has access to much more natural light and scenery.
Of course, to design for large expanses of open corner sliding glass doors, architects must give greater thought to structural considerations at an early stage. The primary consideration for the size of open corner sliding glass doors is therefore the width at which engineers can design an opening with a header that does not deflect. From the manufacturer's standpoint, with the architect's structural work executed adequately, Western Window Systems, for example, can design multi-slide glass doors up to 60-70 feet wide. For its Classic series, these doors are typically a maximum of 12 feet tall. However, using its Performance series, glass sliding doors up to 17 feet tall can be incorporated.
Some architects use additional corner supports removed from the sliding glass door track to ensure that structural requirements are met for the use of these open corner doors. For example, the home shown above, designed by A Parallel Architecture, uses the open corner glass sliding doors to merge the interior living room area with additional outdoor patio space, including a dining table, chairs, and infinity pool. While the design includes a structural support, it remains detached from the glass door track, retaining the sense of a dissolved wall and open space.
Likewise, the above house designed by Jonathan Segal FAIA uses an interior column at the comer to support an almost completely open ground floor with open corners and enormous sliding glass doors. Through these doors and a concrete floor that remains consistent throughout both "interior· and "exterior," the traditional boundary between the two seems almost completely obliterated.
Open corners have the ability to open up a space immensely, invisibly merging indoor rooms with outdoor areas and bringing in both light and scenery. Without opaque walls delineating corners and boundaries, users can feel much more connected with nature, and a home, while retaining the same square footage, can feel unlimited, extending as far as the horizon line. Architects looking for ways to widen a space and facilitate outdoor living must consider the open corner sliding glass door – an extraordinary way of opening a home to nature.