Once you know you want Schüco sliding doors, the real question is ASE 60 or ASE 80. They look similar in a brochure and behave very differently in a build. Here is how to choose without over-specifying.
The headline difference
The number is the frame depth. ASE 80 gives you more room for insulation inside the profile and a heavier glass allowance, so it posts better U-values and handles taller panels. ASE 60 is lighter, shallower and cheaper, and for a standard two- or three-panel opening it is usually all the door you need. Start from our full ASE 60 guide if you have not already.
- ASE 60 depth
- 60 mm
- ASE 80 depth
- 80 mm
- ASE 80 tracks
- double or triple
- Best for 60
- typical domestic openings
- Best for 80
- very large / low-energy builds
Thermal performance
If you are chasing a low whole-door U-value — for a Passivhaus, an energy retrofit, or simply a north-facing wall of glass — the deeper 80 chamber and its warm-edge detailing pull ahead. For most extensions the 60 with a good double-glazed unit already lands in comfortable territory. The glass specification often matters more than the frame here; see understanding U-values.
Panels, tracks and corners
ASE 80's triple-track lets three sashes stack into one pocket, which is how you clear a very wide aperture. It also supports slim interlocks for near-frameless corner openings. If a structural glazed corner is the dream, the 80 is the platform. For slimmer everyday sliders, look at slim-frame sliding doors.
Which one, in plain terms
Choose ASE 60 for a normal rear extension where cost and clean sightlines matter. Choose ASE 80 when the opening is exceptionally wide, the energy target is aggressive, or you want a triple-track or corner. Either way, both are worth seeing configured in a showroom — the Hertfordshire showroom lets you compare the two side by side rather than guessing from a PDF.