Three ways to open the back of the house. All three are quoted routinely by aluminium fabricators. All three do different things, and picking the wrong one is the single most common regret in this category.
The three configurations, briefly
- Bifold — multiple panels hinged together, folding to one side, stacking concertina-style out of the way.
- Sliding — two or more panels on parallel tracks, sliding past each other. One or more panels remain visible when open.
- Lift-and-slide — a heavy-duty sliding system with a lifting mechanism, used for very large panels.
When to choose bifold
Bifolds are the right choice when:
- You want the opening fully clear — no visible panel remaining in the aperture.
- The opening is small-to-medium (up to ~5m).
- You'll actually open the door frequently — daily onto a patio or garden.
- Aesthetically, the folded stack is acceptable.
Bifolds are the wrong choice when:
- Sightline through the closed door matters most (they have more visible aluminium than sliding when shut).
- The opening is very large — bifolds above 6m start feeling architecturally busy.
- The door is a "view door" that will be closed 95% of the time. Sliding delivers a slimmer sightline for that use case.
When to choose sliding
Sliding doors — ASE 60 and above — are the right choice when:
- The door will be closed most of the time and the primary experience is looking through it.
- You want the slimmest sightlines a mainstream aluminium system can deliver.
- The opening is medium-to-large (3m to ~7m).
- Fully clearing the opening isn't essential — a stacked half-open configuration is fine.
Sliding is the wrong choice when:
- You need the opening completely unobstructed — sliding always leaves at least one panel in the aperture.
- The panels would exceed the system's weight limit (typically 250kg for ASE 60, 400kg for ASE 80).
When to choose lift-and-slide
Lift-and-slide (the ASE 80 HI) is the right choice when:
- The opening is genuinely large (typically above 5–6m).
- Panel weights would exceed 250–300kg — you'd struggle to operate a standard slider.
- The exposure is significant and enhanced weather sealing is a real requirement.
Lift-and-slide is the wrong choice when:
- The opening is standard-sized — you're paying for capacity you don't need.
- The operator (an elderly parent, for instance) may struggle with the two-part handle motion.
Comparative sightlines
| Configuration | Typical meeting sightline | When closed |
|---|---|---|
| Schüco AS FD 75 bifold (4-panel) | ~124mm | Three vertical aluminium lines across the opening |
| Schüco ASE 60 sliding (2-panel) | ~65mm | One vertical line at the meeting stile |
| Schüco ASE 80 Panorama (2-panel) | ~30mm | One very slim vertical line at the meeting stile |
| Schüco ASE 80 HI lift-and-slide (2-panel) | ~35mm | One slim vertical line at the meeting stile |
Comparative cost per metre of opening
At installed prices for typical 2.2m tall configurations, per metre of opening width:
- ASE 60 sliding: £2,500–£3,500 / linear metre
- AS FD 75 bifold: £2,800–£3,800 / linear metre
- ASE 80 Panorama sliding: £3,500–£5,000 / linear metre
- ASE 80 HI lift-and-slide: £4,500–£6,500 / linear metre
The question we'd actually start with
Before comparing systems, we'd ask homeowners one question: how often will you actually open this door fully?
If the answer is "daily onto a patio" — bifold. If the answer is "we'll open one side to walk out but usually just look through the closed glass" — sliding. If the answer is "the opening is massive and we want minimal frame" — lift-and-slide. The system follows the use, not the other way round.
Sourcing all three locally
5EC Aluminium quotes all three configurations across their Buntingford, Hemel Hempstead, and St Albans coverage areas — useful when you're benchmarking one against another.
For manufacturer product data, Schüco UK publishes technical dossiers for all three systems.