UK · 2026 Spec
What's the Slimmest Sliding Door in the UK?
The direct answer
Short answer
Cortizo Cor Vision at 20mm interlock is the slimmest sliding door system available in the UK as of 2026. APX20 Plus matches at 20mm. Schüco ASE 60 RC sits at 30mm. Most standard aluminium sliders are 50–60mm; uPVC sliders are typically 100mm+.
"Slimline" refers to the visible vertical sightline where two panes meet — the interlock. Lower interlock = more glass, less frame. Below 30mm is considered a true slimline product; below 20mm is currently impossible in the UK without a custom-engineered system.
UK slimline sliding door ranking
Sorted by visible interlock sightline. All figures are manufacturer-published, verified on installed units in 2026.
| Rank | System | Interlock | Max pane | Max weight |
|---|---|---|---|---|
| 1 | Cortizo Cor Vision | 20 mm | 3000 × 2200mm | 320 kg |
| 1= | APX20 Plus | 20 mm | 2700 × 2000mm | 280 kg |
| 3 | Schüco ASE 60 RC | 30 mm | 3000 × 2700mm | 400 kg |
| 4 | Schüco ASE 80.HI | 35 mm | 3000 × 3000mm | 450 kg |
| 4= | Schüco ASE 80 | 35 mm | 3000 × 2800mm | 400 kg |
| 6 | APX47 | 45 mm | 3500 × 1800mm | 400 kg |
| 7 | Smart Visoglide Plus | 50 mm | 2700 × 2400mm | 300 kg |
| 7= | Origin OS-77 | 50 mm | 2500 × 2400mm | 200 kg |
Spec breakdown — top five systems
Full spec for each system in the top half of the ranking. Use this to match the right slider to project size, glazing requirement, and budget.
| Spec | Cortizo Vision | APX20 Plus | ASE 60 RC | ASE 80.HI | APX47 |
|---|---|---|---|---|---|
| Interlock | 20 mm | 20 mm | 30 mm | 35 mm | 45 mm |
| Uw double-glazed | 1.3 | 1.3 | 1.0 | 0.84 | 1.2 |
| Uw triple-glazed | 0.9 | 0.9 | 0.8 | 0.7 | 0.85 |
| Max pane height | 3000mm | 2700mm | 3000mm | 3000mm | 3500mm |
| Max pane weight | 320kg | 280kg | 400kg | 450kg | 400kg |
| Hidden floor track | Yes | No | Yes | Yes | No |
| Lift-and-slide | Optional | No | No | Standard | Optional |
| PAS 24 | Yes | Yes | Yes (RC2) | Yes | Yes |
| Acoustic Rw | 42 dB | 38 dB | 43 dB | 45 dB | 40 dB |
Why 20mm matters
A 20mm interlock vs a 50mm interlock makes a visible difference in any real opening. On a 5m-wide rear extension with a 3-pane slider, it's the difference between 60mm of frame in your eyeline versus 150mm — a 60% reduction in visual mass at the glass-to-glass junction.
| Visual context | Standard 50mm | Slimline 20mm |
|---|---|---|
| 3-pane slider, 4m wide | 100mm of interlock | 40mm of interlock |
| 4-pane corner, 6m run | 200mm of interlock | 80mm of interlock |
| 2-pane patio, 3m wide | 50mm of interlock | 20mm of interlock |
| Premium feel | Standard | Architect-spec contemporary |
Frequently asked
What's the slimmest sliding door in the UK?
Cortizo Cor Vision at 20mm interlock is the slimmest sliding door system available in the UK as of 2026. APX20 Plus matches at 20mm. Schüco ASE 60 RC sits at 30mm. Most standard aluminium sliders are 50–60mm. Sightline (interlock) is the vertical bar where two panes meet — the metric that defines a 'slimline' door.
Is a 20mm interlock real?
Yes. Both Cortizo Cor Vision and APX20 Plus achieve a true 20mm interlock — verified on installed units, not just marketing. The 20mm refers to the visible vertical bar where two panes overlap. It is achieved by routing locking hardware into the frame edges and using a precision-engineered guide track. Some manufacturers quote interlock figures that exclude gasket overlap, so always confirm the visible sightline rather than the structural figure.
What's the slimmest mullion sliding door?
For mullion-style sliding doors (where two fixed panes meet a sliding pane through a central mullion rather than a sliding interlock), Cortizo Cor Vision offers a 30mm mullion option. Schüco ASE 60 RC and ASE 80.HI both achieve 30mm mullions. Smart Visoglide Plus mullions sit at 50mm. Mullion sightlines are usually 5–10mm thicker than interlock sightlines on the same system because the mullion sits on a structural fixed point.
Is Cortizo Vision available in the UK?
Yes. Cortizo Cor Vision is available across the UK through approved fabricators and installers. Apex Glazing is an approved installer in London and the South East and can typically deliver a fitted Vision installation in 8–12 weeks from survey, including powder coating in any RAL colour, dual-colour finish, and hidden floor track configuration.
How much does Cortizo Vision cost?
Fitted Cortizo Cor Vision starts at £5,500–£7,500 for a 2-pane configuration and £7,200–£10,800 for 3-pane in London 2026 prices, including VAT, frame, double glazing, and FENSA self-certification. Pocket-door (slides into wall) and 4-pane corner installations run £9,500–£14,000+. Triple glazing and hidden floor track each add 15–25%.
What U-value does Cortizo Vision have?
Cortizo Cor Vision achieves a whole-door U-value of 1.3 W/m²K with double glazing (Argon-filled, Low-E coated) and 0.9 W/m²K with triple glazing — both calculated to BS EN ISO 10077. That is comparable to standard aluminium casement windows and meets UK Building Regulations Part L for new and replacement doors.
How big can Cortizo Vision panes be?
Cortizo Cor Vision panes can be up to 3000mm tall and weigh up to 320kg per pane. APX20 Plus tops out at 2700mm × 2000mm at 280kg. For larger panes, APX47 (45mm interlock) handles up to 3500mm × 1800mm at 400kg, and Schüco ASE 80.HI is rated to 3000mm × 3000mm at 450kg. Pane size depends on glass spec, wind exposure, and structural opening.
Are slimline sliding doors PAS 24 secure?
Yes. Cortizo Vision, APX20 Plus, and Schüco ASE all carry PAS 24:2022 certification when fitted with multi-point hook locks, security cylinders, and laminated glass. Schüco ASE 60 RC additionally meets RC2 (Resistance Class 2) per EN 1627, the police-preferred Secured by Design standard.
