Compare minimal-frame sliding door systems
Twelve systems from four manufacturers, all built to make the frame disappear — and all good at different things. This page sets out the published figures side by side, then explains which system suits which opening, so a decision is made on engineering rather than on marketing.
The place to start is the sightline: the visible width of frame you actually see. It runs from 18 mm on MFP18 to 55 mm at the panel joint on the Solarlux lift-and-slide systems, and where a system sits on that scale decides what else it can do — panel size, thermal performance, threshold detail and security class. Every figure below is published by the manufacturer.
Every system, side by side
| System | Family | Sightline | Max panel | Glazing | Uw | Security | Best for |
|---|---|---|---|---|---|---|---|
| MFP18-H30MFP18 | MFP18 | 18 mm | 6 m² | 28 mm double | Uw 1.3 W/m²K | RC2 | Standard residential openings, garden rooms and extensions. |
| MFP18-H40MFP18 | MFP18 | 18 mm | 18 m² | 38 mm double | Uw 1.26 W/m²K | RC2 | Large architectural openings, tall glazing and exposed sites. |
| MFP18-H50MFP18 | MFP18 | 18 mm | 18 m² | 48 mm triple | Uw 1.05 W/m²K | RC2 | High-performance homes and cold, exposed or coastal locations. |
| Vitrocsa 30013001 | Vitrocsa | 18 mm | 6 m² | 26 mm | Not published | RC2 | Hot climates, internal partitions and heritage openings. |
| MFP 20MFP20 | MFP 20/25 | 20 mm | 7.5 m² | 26–30 mm | Uw ≥ 1.3 W/m²K | Multi-point | Perimeter-concealed openings and cost-efficient minimalism. |
| Vitrocsa V56V56 | Vitrocsa | 22 mm | < 20 m² | 56 mm | Not published | RC2 option | The largest openings and landmark architecture. |
| Vitrocsa TH+TH+ | Vitrocsa | 22 mm | 18 m² | 32–44 mm | Not published | RC2 option | UK homes wanting maximum glass with real thermal performance. |
| Vitrocsa V32V32 | Vitrocsa | 23 mm | 12 m² | 32 mm | Not published | RC2 Compliant | Standard sliding openings that need thermal reinforcement. |
| MFP 25MFP25 | MFP 20/25 | 25 mm | 16 m² | up to 56 mm | Uw ≥ 0.9 W/m²K | Multi-point + flip handle | Statement openings, wide garden rooms and panoramic living spaces. |
| Solarlux cero IIIcero III | Solarlux | 34 mm | 15 m² | triple | Uw ≤ 0.80 W/m²K | RC3 | Passive house projects needing maximum thermal performance at scale. |
| Solarlux Ecoline SEcoline S | Solarlux | 55 mm | 6.75 m² | 28 mm double | Uw ≥ 1.4 W/m²K | Multi point Locking | Projects combining sliding panels with Solarlux bi-folding doors, windows and balustrade glazing. |
| Solarlux Highline SHighline S | Solarlux | 55 mm | 8.96 m² | 22–60 mm | Uw ≥ 0.9 W/m²K | Multi point Locking | Tall, thermally demanding openings where sliding panels must match a Solarlux aluminium facade. |
Sorted by sightline, slimmest first. Uw is the whole-door thermal transmittance — glass, frame and seals together — and where a manufacturer publishes no figure it is shown as not published rather than estimated. Current figures for your specification are confirmed in writing with your quotation.
Which system suits which opening
Start with the one thing that cannot be compromised — the thing your project cannot do without — and work outwards from there.
If the slimmest possible sightline is the priority
The answer is 18 mm, and only two systems offer it: the MFP18 range (H30, H40 and H50) and the Vitrocsa 3001. For a UK project the MFP18 range is normally the practical choice, because it carries large domestic panels — up to 18 m² and 6 m tall on the H40 and H50 — on 38 mm or 48 mm glazing. The Vitrocsa 3001 uses 12–26 mm glazing and is designed for warm climates, internal partitions and heritage openings.
If 22–23 mm is slim enough, the Vitrocsa V56, TH+ and V32 systems open up much larger panels on thermally broken tracks, and MFP 20 gives a 20 mm central junction with the frame concealed around the perimeter.
If thermal performance is the priority
Solarlux cero III is the only passive house certified system here, at Uw ≤ 0.80 W/m²K, with triple glazing, a 72 mm panel depth and RC3 security. That performance comes with a 34 mm sightline — the widest of the four families — which is exactly the trade-off to understand before you specify it.
If passive house is not required, MFP18-H50 achieves Uw 1.05 W/m²K and Ug 0.5 on 48 mm triple glazing inside an 18 mm frame, and Solarlux Highline S offers Uw ≥ 0.9 with Ug 0.6 including a warm edge spacer.
If the panels are enormous
Vitrocsa V56 carries panels under 20 m² on 56 mm glazing — the largest single panel in the range. MFP18-H40 and H50 reach 18 m² and up to 6 m in height, Vitrocsa TH+ 18 m² on 32–44 mm double or triple glazing, MFP 25 panels to 4 × 4 m, and Solarlux cero III 15 m² at up to 1,000 kg per panel.
If the door has to line up with the rest of the facade
Solarlux Ecoline S and Highline S publish a uniform 55 mm sightline at the panel joint, deliberately matching connected Solarlux windows and bi-folding doors so the glass lines run level with no visible offset. Where a project already includes Solarlux windows or bi-folds, that alignment is usually worth more than a few millimetres of frame.
If level access and drainage matter most
MFP18 has an integrated stainless-steel gutter and drainage with an integrated flush floor threshold. MFP 25 offers a continuous flush threshold with optional ACO drainage. Solarlux systems use level-access tracks with cascading drainage, and Highline S integrates a brush that cleans the rail as the panel moves. Vitrocsa runs on thermally broken tracks with stainless-steel 4×4 floor bearings and is Part M compliant with a flush level-access floor — the system to specify where an accessible route crosses the opening.
If security certification is required
Solarlux cero III publishes RC3, the highest certified level in the range. MFP18 publishes RC2 across the range, Solarlux Highline S publishes RC2/RC2N, and the Vitrocsa systems offer RC2 as an option. MFP 20 and MFP 25 use multi-point locking, with a security flip handle as standard on MFP 25.
If you want minimalism at the keenest level of cost
MFP 20 delivers a 20 mm central junction, a perimeter-concealed frame and a sash up to 2,500 × 3,000 mm at a lower level of complexity than the largest systems. Beyond the system itself, cost is driven by the opening as much as the product: panel size and weight, glazing build, motorisation, threshold and drainage works, structural work and site access — all of which are set out in our cost guide.
Comparison questions we are asked
Which minimal-frame system has the slimmest sightline?
18 mm — the MFP18 range (H30, H40 and H50) and the Vitrocsa 3001. Of those, the MFP18 range carries the larger domestic panels, up to 18 m² and 6 m tall on 38 mm or 48 mm glazing, while the Vitrocsa 3001 is designed for warm climates, internal partitions and heritage openings on 12–26 mm glass.
Can a minimal-frame sliding door be passive house certified?
Yes. Solarlux cero III is passive house certified at Uw ≤ 0.80 W/m²K with triple glazing and a 72 mm panel depth, so it is the system to specify when certified performance is the requirement. The trade-off is its 34 mm sightline — the widest of the four families we install.
What is the largest single glass panel I can have?
Under 20 m² on the Vitrocsa V56 with 56 mm glazing. MFP18-H40 and H50 carry 18 m² up to 6 m tall, Vitrocsa TH+ 18 m² on 32–44 mm glazing, MFP 25 panels to 4 × 4 m, and Solarlux cero III 15 m² at up to 1,000 kg per panel. Panel weight, not just area, usually decides what is possible.
Do all of these systems offer a flush, level threshold?
No, and it is worth checking before you settle on a system. MFP18 has an integrated flush floor threshold with a stainless-steel gutter and drainage; MFP 25 has a continuous flush threshold with optional ACO drainage; Solarlux systems use level-access tracks with cascading drainage; and Vitrocsa is Part M compliant with a flush level-access floor.
Which system gives strong thermal performance without passive house certification?
MFP18-H50 — 48 mm triple glazing, Uw 1.05 W/m²K and Ug 0.5 in an 18 mm frame. Solarlux Highline S is the next step up at Uw ≥ 0.9 with Ug 0.6 including a warm edge, on lift-and-slide panels to 3,200 × 2,800 mm.
How many panels can stack to one side?
MFP 25 stacks up to eight sliding sashes in its quad-track configuration, and MFP18 stacks up to four panels to one side with unlimited rails. Solarlux cero III, Ecoline S, Highline S and the Vitrocsa systems are specified as corner, side, centre or pocket openings rather than stacking layouts.
Take the shortlist to a specification
Send us your opening and drawings and we will confirm the system, the published figures for it and a quotation — including anything that needs engineering before it can be guaranteed.