Technical information notice. Technical information on this page is general product-selection guidance, not a certification, compliance statement, design calculation or order confirmation. Before relying on a figure or standard, request current evidence for the selected product route, size, glazing, hardware and project. See our technical information.
Guide
How big can aluminium doors and windows go?
Aluminium goes large where uPVC and timber stop. Across our systems, bifold leaves run to 1.2 x 3.0m at 130kg, sliding sashes to 2.2 x 2.87m at 420kg, casements to 1.3 x 2.4m at 160kg, and curtain walling units to 1.5 x 3.6m at 350kg. The figures below are real per-system maximums, given as "up to" and "from". Whole-unit performance is confirmed at quote, because the limit on any one opening is the interaction of width, height, weight, glass make-up and exposure, not a single headline number.
Verified maximumsReal per-system figures: width x height, weight, leaves and clear opening
Trade fabricatorWe fabricate and supply the trade; homeowners routed to vetted installers
Confirmed at quoteWhole-unit limits validated against glass, weight and exposure
What are the maximum aluminium door and window sizes by system?
Each system has its own maximum leaf, sash or unit size, governed by frame depth, hardware rating and glass weight. Use the figures below as the ceiling for a single element, then confirm the whole unit at quote. All figures are stated as "up to" for size and weight and "from" for U-values.
Request current product evidence for the selected route, size, glazing, hardware and project before relying on the specification.
| Bifold doors | leaves up to 1.2 x 3.0m at up to 130kg per leaf, up to 14 leaves per run, around 90% clear opening, Uw from 0.9. |
|---|---|
| Sliding doors | sashes up to 2.2 x 2.87m at up to 420kg per sash, 35mm interlock, around 50 to 65% clear opening, Uw from 1.0. |
| Casement windows | vents up to 1.3 x 2.4m at up to 160kg, Uw from 0.85. |
| Tilt-turn windows | Uw from 0.71 on the high-insulation route, sized to the same casement envelope where specified. |
| Entrance doors | leaves up to 1.2 x 2.4m, Uw from 1.1. |
| Heritage sliding sash windows | up to 1.8 x 1.8m at up to 100kg, Uw from 1.0. |
| Steel-look screens and doors | internal and external leaves up to 1.25 x 3.1m at up to 160kg. |
| Curtain walling | units up to 1.5 x 3.6m at up to 350kg, 66mm sightline, Ucw from 0.6. |
How big can aluminium bifold doors go?
Aluminium bifold leaves run up to 1.2m wide by 3.0m tall at up to 130kg each, with up to 14 leaves in a single run. That gives an expansive opening with around 90% clear width when the leaves are stacked. Uw is from 0.9 where specified. Tall, heavy leaves shift more load onto the track and hardware, so the exact leaf count and weight per leaf are confirmed at quote against the chosen glass make-up.
See the full range on products or compare formats at bifold vs sliding doors.
| Max leaf size | up to 1.2 x 3.0m |
|---|---|
| Max weight | up to 130kg per leaf |
| Max leaves per run | up to 14 |
| Clear opening | around 90% |
| Thermal | Uw from 0.9 |
How big can aluminium sliding doors go?
Aluminium sliding sashes go larger and heavier than any bifold leaf, up to 2.2m wide by 2.87m tall at up to 420kg per sash, on a 35mm interlock. Clear opening lands around 50 to 65% depending on configuration, because one sash slides behind another rather than folding away. Uw is from 1.0 where specified. The 420kg figure is a sash maximum, not a guarantee for every opening; glass specification and panel layout set the real limit, confirmed at quote.
| Max sash size | up to 2.2 x 2.87m |
|---|---|
| Max weight | up to 420kg per sash |
| Interlock | 35mm |
| Clear opening | around 50 to 65% |
| Thermal | Uw from 1.0 |
How big can aluminium casement and tilt-turn windows go?
Aluminium casement vents go up to 1.3m wide by 2.4m tall at up to 160kg, with Uw from 0.85. Tilt-turn reaches Uw from 0.71 on the high-insulation route, sized to the same opening envelope where specified. Large vents put significant load on hinges and the locking line, so for the biggest openings the weight, glass weight and hardware are validated at quote rather than assumed from the headline size.
More on glazing and thermal performance at energy efficiency and aluminium U-values.
| Casement max vent | up to 1.3 x 2.4m at up to 160kg, Uw from 0.85 |
|---|---|
| Tilt-turn thermal | Uw from 0.71 on the high-insulation route |
| Glazing | 22 to 58mm by system |
| Weather | air permeability Class 4, watertightness to Class 9A, wind resistance to Class C5 |
How big can aluminium entrance, heritage and steel-look units go?
Entrance doors run up to 1.2m wide by 2.4m tall, with Uw from 1.1. Heritage sliding sash windows go up to 1.8 x 1.8m at up to 100kg, Uw from 1.0, holding a slim traditional sightline. Steel-look screens and doors take internal and external leaves up to 1.25m wide by 3.1m tall at up to 160kg, for tall slim-framed glazed runs. Each is a single-element maximum; the working size for a given opening is set against weight, glass and exposure at quote.
Browse formats on products or start a spec at quote.
| Entrance doors | up to 1.2 x 2.4m, Uw from 1.1 |
|---|---|
| Heritage sliding sash | up to 1.8 x 1.8m at up to 100kg, Uw from 1.0 |
| Steel-look leaves | up to 1.25 x 3.1m at up to 160kg, internal or external |
How big can aluminium curtain walling go?
Aluminium curtain walling carries units up to 1.5m wide by 3.6m tall at up to 350kg, on a 66mm sightline, with Ucw from 0.6 where specified. It is engineered to EN 13830, with air permeability to Class AE, watertightness to RE1200 and wind resistance to EN 13116 2000Pa design. For full-height glazed facades the unit size, weight and fixing are engineered to the building, so the maximum is confirmed against the project at quote.
| Max unit size | up to 1.5 x 3.6m at up to 350kg |
|---|---|
| Sightline | 66mm |
| Thermal | Ucw from 0.6 |
| Standards | EN 13830, air permeability to Class AE, watertightness to RE1200, EN 13116 2000Pa design wind |
What limits the maximum size of an aluminium opening?
The real limit on any opening is the interaction of width, height, weight, glass make-up and exposure, not a single headline number. A leaf can hit its size maximum or its weight maximum first, depending on the glass. Thicker acoustic or triple glazing adds weight that can pull a large leaf below its dimensional ceiling.
Exposure matters too: every system is tested for air permeability to Class 4 (EN 12207), watertightness to Class 9A (EN 12208) and wind resistance to Class C5 (EN 12210), with acoustic performance to Rw 46 dB and durability to 50,000 cycles (EN 12400). PAS 24 routes including PAS 24:2025 are available where security is specified.
Because of these trade-offs, every whole unit is confirmed at quote.
See security for PAS 24 routes, or send your sizes via quote. Homeowners are routed to vetted installers through find an installer; trade buyers start at trade.
| Glazing weight | 22 to 58mm by system, heavier units reach the weight limit before the size limit |
|---|---|
| Weather and wind | air permeability Class 4, watertightness to Class 9A, wind resistance to Class C5 |
| Acoustic | to Rw 46 dB where specified |
| Durability | 50,000 cycles (EN 12400) |
| Security | PAS 24 routes including PAS 24:2025 |
Common questions
What is the biggest aluminium door you can get?
The largest single element is a sliding sash up to 2.2m wide by 2.87m tall at up to 420kg, on a 35mm interlock with Uw from 1.0. Bifold leaves reach 1.2 x 3.0m at up to 130kg each with up to 14 leaves per run for the widest overall opening. The working maximum for any one door is confirmed at quote against glass and exposure.
How wide can aluminium bifold doors open?
Aluminium bifold doors take leaves up to 1.2m wide by 3.0m tall at up to 130kg each, with up to 14 leaves in a single run and around 90% clear opening when stacked. Uw is from 0.9 where specified. The exact leaf count and weight per leaf are confirmed at quote against the chosen glass.
How heavy can an aluminium sliding sash be?
A single aluminium sliding sash can run up to 420kg, sized up to 2.2 x 2.87m on a 35mm interlock, with around 50 to 65% clear opening. The 420kg figure is a sash maximum, not a guarantee for every opening; the real limit is set by glass make-up and panel layout, confirmed at quote.
How big can aluminium curtain walling units be?
Aluminium curtain walling carries units up to 1.5m wide by 3.6m tall at up to 350kg, on a 66mm sightline with Ucw from 0.6. It is engineered to EN 13830 with air permeability to Class AE, watertightness to RE1200 and EN 13116 2000Pa design wind. Unit size and fixing are engineered to the building and confirmed at quote.
Why are aluminium maximum sizes given as up to and from?
Because the limit on any opening is the interaction of width, height, weight, glass make-up and exposure, not one fixed number. A leaf can reach its size maximum or its weight maximum first depending on the glass, and exposure sets the weather and wind requirement. So sizes are given as up to, U-values as from, and every whole unit is confirmed at quote.
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