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
Aluminium window styles explained
Pick the style by how the window opens and what the opening has to do. Casements hinge outward for the widest open vent and the simplest detail; tilt-and-turn give secure background vent and inward cleaning on one handle; heritage and slim sashes suit period frontages; fixed lights add glass with no hardware. Most jobs mix two or three styles in one screen. Verified sizes and U-values sit below, each confirmed at quote on the specified system.
Casement to 1.3x2.4m, 160kgSide or top hung, Uw from 0.85
Tilt-and-turn high-insulation route, Uw from 0.71Dual action on one handle
Trade-supplied, made to orderMix styles in one screen to suit the opening
How does each aluminium window style open?
The opening action is the first decision because it sets ventilation, cleaning and egress. Each style below is supplied to the trade, made to order, sized and finished to the project.
Request current product evidence for the selected route, size, glazing, hardware and project before relying on the specification.
| Casement | hinges on the side (side hung) or top (top hung) and swings outward. Widest clear opening for its size, simplest hardware. |
|---|---|
| Tilt-and-turn | one handle, two actions. Tilt inward at the top for secure background vent, or turn fully inward like a door for full opening and inside cleaning. |
| Sliding sash and heritage | vertical sliding sashes or slim sightline casements that match period proportions on traditional frontages. |
| Fixed light | does not open. Maximum glass, slimmest frame, used to add daylight and views where vent is not needed. |
| Combination | two or more of the above in one framed screen, for example fixed centre lights flanked by opening casements. |
Casement or tilt-and-turn: which suits the room?
Choose casement for the widest open vent and the cleanest external look; choose tilt-and-turn where you want secure ventilation, easy inside cleaning and door-like full opening.
Casements suit most rooms and elevations and give a slim, consistent line across a frontage. Tilt-and-turn suit higher floors, kitchens and anywhere you want to vent on the tilt while staying secure, then turn fully open to clean the outside glass from indoors.
| Casement | outward swing, best clear opening, simple detail, ventilation from a crack to fully open. |
|---|---|
| Casement size and weight | to 1.3x2.4m at up to 160kg per opening sash, confirmed on the specified system. |
| Casement thermal | Uw from 0.85 where specified, whole-unit figure confirmed at quote. |
| Tilt-and-turn | inward tilt for secure background vent, inward turn for full opening and inside cleaning. |
| Tilt-and-turn thermal | Uw from 0.71 on the high-insulation route, confirmed at quote. |
| Reach and access | tilt-and-turn cleaned from inside; outward casements may need external access at height. |
Which style ventilates and which is easiest to clean?
For controlled background ventilation with security, tilt-and-turn lead; for the largest open vent, casements lead; for cleaning, tilt-and-turn win because the glass turns inward to you.
Match the action to the room. Bedrooms and bathrooms often want secure night vent, which favours the tilt position. Living spaces that open wide in summer favour casements. Upper floors favour any style you can clean from inside.
| Most open vent | side or top hung casement, fully swung out. |
|---|---|
| Secure background vent | tilt-and-turn on the tilt setting. |
| Easiest cleaning at height | tilt-and-turn, turned inward to clean the outer glass indoors. |
| Fixed lights | no vent, cleaned externally, so plan access where they sit high or wide. |
| Heritage and sliding sash | vent by sliding or opening the sash, in keeping with the period look. |
What about egress and fire-escape openings?
Where a room needs an escape window, the opening style and clear dimensions must meet the relevant Building Regulations for that room, confirmed at design stage.
Side-hung casements and the turn action on a tilt-and-turn both give a clear route. The free area and minimum dimensions are set by regulation, not by the frame alone, so escape openings are specified and checked per opening rather than assumed from the style name. Tell us which openings are escape windows and we size the sash and hardware to suit.
- Egress is defined by clear opening area and minimum width and height, not by style label.
- Side-hung casement: common escape choice, swings clear in one action.
- Tilt-and-turn: the turn action opens fully for escape; the tilt alone does not.
- Confirm escape openings at design so the sash size, hinge and restrictor are specified correctly.
Where does each window style suit best?
Match the style to the elevation and the job: casements for most new and replacement work, tilt-and-turn for security and access, heritage and sliding sash for period frontages, fixed lights for daylight, combinations for larger openings.
Mixing styles in one screen is normal. A wide opening often reads best as fixed centre glass with opening casements or tilt-and-turn either side, keeping sightlines consistent while putting the vent and escape where they are needed.
| Casement | general purpose, slim consistent line, broadest fit across elevations. |
|---|---|
| Tilt-and-turn | upper floors, security-led rooms, glass cleaned from inside. |
| Heritage and slim sash | period and conservation-sensitive frontages. |
| Fixed light | gable glass, picture windows and daylight where no vent is needed. |
| Combination | large openings split into fixed and opening zones in one frame. |
| See the full range on our products page. |
How do the styles compare on size, weight and thermal performance?
Casement is verified to 1.3x2.4m at up to 160kg per sash with Uw from 0.85; the tilt-and-turn high-insulation route reaches Uw from 0.71. Each figure is a maximum or a from-figure on the specified system, confirmed at quote.
Glazing runs from 22mm to 58mm depending on the system, which is what lets the same style hit different acoustic and thermal targets. Tell us the target and the opening and we quote the right system across our range rather than forcing one product to fit. For the detail behind the numbers, see our guide to aluminium U-values.
| Casement | to 1.3x2.4m, up to 160kg per sash, Uw from 0.85 where specified. |
|---|---|
| Tilt-and-turn | high-insulation route to Uw from 0.71, confirmed at quote. |
| Glazing | 22mm to 58mm by system, set by thermal and acoustic target. |
| Finishes | full RAL, dual-colour, anodised-style, matt, satin, gloss and textured architectural powder coat. |
| Security | PAS 24 including PAS 24:2025 where specified. See our security page. |
| Whole-unit Uw and weather ratings are confirmed per opening at quote. |
Common questions
What is the difference between a casement and a tilt-and-turn window?
A casement hinges on the side or top and swings outward, giving the widest clear opening for its size and the simplest external line. A tilt-and-turn uses one handle for two actions: tilt inward at the top for secure background ventilation, or turn fully inward like a door for full opening and inside cleaning. Casement reaches Uw from 0.85 and to 1.3x2.4m at up to 160kg per sash; the tilt-and-turn high-insulation route reaches Uw from 0.71, both confirmed at quote on the specified system.
Which aluminium window style is easiest to clean from inside?
Tilt-and-turn is easiest to clean from inside because the sash turns fully inward, bringing the outer glass to you. That makes it the practical choice for upper floors and anywhere external access is awkward. Outward-opening casements and fixed lights are normally cleaned from outside, so plan access where they sit high or wide.
Can a window be used as a fire-escape opening?
Yes, where the clear opening meets the Building Regulations for that room. Egress is defined by free opening area and minimum width and height, not by the style name. Side-hung casements and the turn action on a tilt-and-turn both give a clear route; the tilt position alone does not. Tell us which openings are escape windows and we specify the sash size, hinge and restrictor to suit, confirmed at design stage.
What size can aluminium casement windows be made to?
Aluminium casements are supplied to 1.3x2.4m at up to 160kg per opening sash, as a maximum on the specified system and confirmed at quote. Thermal performance reaches Uw from 0.85 where specified, with glazing from 22mm to 58mm depending on the system. Larger openings are usually split into a combination of fixed lights and opening sashes in one framed screen.
Can I mix window styles in one opening?
Yes. Combining styles in a single framed screen is standard. A wide opening often works best as fixed centre glass flanked by opening casements or tilt-and-turn, keeping sightlines consistent while putting ventilation and any escape opening where they are needed. Tell us the opening and the target performance at quote and we configure the right mix across our range.
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