Why two names.
Bifold (literally two-fold) refers to the panel folding behaviour and is the trade term carried over from the original European systems. Accordion describes how the door looks while operating (panels folding like an accordion bellows) and entered consumer vocabulary through retail product catalogs in the mid-twentieth century.
The terms are interchangeable on commercial and residential exterior glass walls. On interior partitions and room dividers, accordion is more often used (think temporary classroom dividers), and bifold tends to refer specifically to the modern aluminum-and-glass exterior product. Both are the same fundamental folding-panel system.
What to call it.
For a modern aluminum-and-glass system opening to a patio or garden, the correct trade term is bifold door. Architectural drawings, NAFS test reports, and product approval databases use bifold. Search engines map both terms to the same product, so a listing titled bifold and a listing titled accordion compete for the same intent.
Crateworks builds bifold doors in thermally-broken aluminum, made to your opening. The same product appears under the accordion name in some catalogs and product searches; the spec, hardware, and look are identical.
Common questions.
- Is an accordion door the same as a bifold door?
- Yes for exterior aluminum-and-glass systems. Both names describe a wall of panels hinged together that folds back on itself to one or both sides. Architectural and trade usage prefers bifold; consumer and retail usage often uses accordion. The product is identical.
- Why are they called accordion doors?
- The name describes how the door looks while operating. The panels fold like the bellows of an accordion. The term entered residential vocabulary through mid-twentieth-century retail and remained in consumer use.
- Which name should I use when specifying or shopping?
- Both work and search engines map them to the same product. When working with a builder, architect, or commercial spec writer, use bifold. When searching for residential products online, both terms return the same product class.
Project in motion
Specifying a bifold or accordion door?
Same product, one quote. Send opening dimensions and we will quote factory-direct.