Bifold Windows

Serving Gardena CA

Bifold windows — sometimes called accordion windows or a folding glass wall — are a series of glazed panels that fold against one another and glide completely out of sight, opening an entire wall of a living space to the outdoors. Where a conventional window frames a view, a bifold window removes the wall between you and it: up to 24 feet of opening, with every panel tucked away and nothing left but air, light, and landscape.

It is the signature gesture of indoor-outdoor architecture — a kitchen that becomes part of the terrace, a great room that ends at the horizon instead of at glass.

Get a consultation on bifold windows for your next build.

How bifold windows work

Each sash is hinged to its neighbor and hung on a German-engineered hinge-and-track system. Release the locking hardware, and the panels fold accordion-style — gliding smoothly to one or both sides until the full opening is clear. Closed, concealed multipoint locking pulls every panel tight against compression seals, returning the wall to a secure, weathertight, fully insulated state. Open in seconds; sealed like a fortress the rest of the year.

Inswing or outswing operation
24 opening schemes — fold left, right, split to both sides, or include a daily-use access leaf
Effortless glide via state-of-the-art German hinge hardware

Built like a window, not a partition

A folding wall is only as good as its weakest seal, which is why HH bifold windows are built to the same standard as our tilt & turn windows:

Triple-overlay construction with full compression seals for genuine energy efficiency
Fully concealed German multipoint locking for high security across every panel
Solid 2 5/8″ laminated vertical-grain Douglas fir (or other select species), with double mortise-and-tenon joinery
Double or triple-pane glazing with the full range of LoE coatings and gas fill
Custom sizes and designs, including large operable sash sizes

In plain terms: the crisp, modern aluminum aesthetic with the thermal performance of a high-end European window.

Bifold window specifications

Specification	Detail
Maximum span	Up to 24′ wide
Operation	Inswing or outswing; 24 opening schemes
Construction	2 5/8″ solid wood, triple-overlay, double mortise-and-tenon
Sealing & security	Compression seals + concealed German multipoint locking
Glazing	Double or triple pane; LoE coatings, gas fill

Designing with bifold windows

The defining decision is the opening scheme: how many panels, folding in which direction, and whether one leaf operates independently for everyday use. From there, panel proportions, wood species, finish color, and glazing are tailored to the project — our team works through configurations directly with the architect or homeowner so the system disappears into the design rather than dictating it. Finish and glazing options mirror the rest of our line; see Tilt & Turn Windows for the full materials story.

Build as a single unit or mull side-by-side and in transom configurations across full elevations. Optional sill profiles are available for both operable and fixed units, and the easily handled frame installs flush with the wall exterior, at wall center, or anywhere between — the closer to center, the better the thermal performance.

Where bifold windows excel

Kitchen pass-throughs — fold the window above the counter away and the island becomes an outdoor bar
Great rooms and entertaining spaces that need to double their footprint onto a terrace
View properties in the San Juans, on the Sound, or above the city, where a mullion is one mullion too many
Pool houses, cabanas, and ADUs where a full bifold door would be more wall than the structure has

For full-height openings, see Bifold Doors — same engineering, floor-to-header scale.

Why HH Windows & Doors

HH Windows & Doors manufactures German-engineered, American-made bifold systems in-house, serving architects, builders, and homeowners from Seattle and Portland to Los Angeles, San Francisco, and New York — with the short lead times and lifetime engineering support that only a domestic manufacturer can offer.

Opening a wall on your next project?

Frequently asked questions

What is a bifold window?

A bifold window is a series of hinged glass panels that fold against each other accordion-style and slide out of sight, opening an entire wall-width aperture to the outdoors — then sealing back into a secure, weathertight wall when closed.

How wide can bifold windows be built?

HH bifold windows span openings up to 24 feet wide, with 24 opening schemes — panels can fold to the left, the right, or split to both sides.

Are bifold windows energy efficient?

Yes. HH bifold windows use triple-overlay construction, full compression seals, concealed multipoint locking, and double or triple-pane LoE glazing, so the closed wall performs like a high-end European window, not a partition.

What is the difference between a bifold window and a bifold door?

Scale and threshold. A bifold window fills a wall opening — often above a counter or knee wall — while a bifold door runs floor to header for walk-through access. The folding hardware and construction principles are the same.

Do bifold windows swing in or out?

Either. HH bifold windows are available in inswing or outswing configurations, chosen to suit the room, furniture plan, and exterior conditions.

Gardena CA

Tilt & Turn Windows · Passive House Windows · All Custom Windows