Profile design
Section depth, wall thickness and chamber layout set wind-load resistance and the space available for thermal breaks and hardware.
Windows for building projects
Aluminium Window Systems
An aluminium window system is a family of matched extruded profiles, gaskets, hardware and glazing details that produces every window type a building needs, from sliding and casement windows to fixed lights and tilt-and-turn units, with consistent appearance and tested performance. Metline supplies the window profiles, thermal-break sections and accessories, selected from your drawings and window schedule, to fabricators for residential, hotel and commercial projects worldwide.
- Profile alloy
- 6063-T5/T6, 6060
- Types
- Sliding, casement, tilt-turn, fixed, hung
- Standards
- EN 14351-1 · NAFS · AS 2047
- Finish
- Powder coat, anodised, wood-grain
What makes a window a "system"?
A window is more than a frame around glass. It has to resist wind pressure, keep out driven rain, limit air leakage, insulate, reduce noise, open and lock reliably for decades and look the same across hundreds of openings. A window system achieves this with a coordinated set of profiles, thermal breaks, gaskets, corner cleats, drainage paths and hardware that has been tested together as a whole.
Aluminium is used because it delivers strength and stiffness in slim sections. A 6063-T6 profile allows narrow sightlines and large glass panes that would need much bulkier frames in PVC or timber, and it does not warp, swell or degrade in sunlight. Modern thermally broken aluminium windows, with polyamide strips separating the inner and outer shells, now reach insulation levels that meet strict energy codes.
For a building project, the real benefit of buying a system is consistency. Sliding windows in the bedrooms, casements in the kitchens, fixed lights in the stairwell and tilt-and-turn units in the living rooms can all share the same colour, glass build-up, hardware family and sightlines, and all be backed by the same test reports.
Aluminium window types and where each fits
Sliding windows
Sashes slide horizontally on rollers, so nothing projects into the room or over the façade. Two- and three-track designs suit apartments, hotels and large openings.
Casement windows
Side-hinged sashes that close against compression gaskets, giving the best air and water tightness of the common types. Inward or outward opening.
Tilt-and-turn windows
One handle tilts the sash inwards for secure ventilation or swings it fully open for cleaning. Standard across much of Europe; multi-point locking.
Awning / top-hung windows
Hinged at the top and opening outwards, so they ventilate even in light rain. Common in kitchens, bathrooms and as vents above fixed glass.
Fixed windows
Non-opening frames for maximum glass area and the simplest, most reliable seal. Often combined with opening sashes in one frame.
Single- and double-hung windows
Vertically sliding sashes, traditional in North America and in British sash-window designs.
Slimline windows
Very narrow visible frames for a minimal look and maximum daylight; popular in villas and hotel projects.
Bifold windows
Folding sashes that stack to one side to open a counter or bar area fully to the outside.
Acoustic windows
Deeper frames, laminated or asymmetric glass and extra seals to cut road, rail and aircraft noise.
Profiles, alloys and thermal breaks
Window profiles are extruded from 6063 or 6060 alloy, aged to T5 or T6 (T66 in Europe). These alloys extrude into thin, complex multi-chamber sections with crisp detail, and their surface takes powder coating and anodising evenly.
| Element | Typical specification | What it controls |
|---|---|---|
| Frame and sash profiles | 6063-T5/T6 or 6060-T66 to EN 755 or ASTM B221 | Strength, stiffness, sightlines |
| Wall thickness | Typically 1.2 – 2.0 mm in visible and structural walls; thicker for large or high-rise windows | Wind-load resistance, screw holding, hardware fixing |
| Thermal break | Polyamide PA66 GF25 strips, typically 14 – 35 mm wide | Heat loss and condensation on the inner frame |
| Gaskets | EPDM, often with a centre gasket in casement and tilt-turn systems | Air and water tightness, acoustic performance |
| Corner joints | Crimped or pinned corner cleats with corner sealant | Frame rigidity, leak prevention at corners |
| Hardware | Multi-point locks, friction stays, rollers, hinges in stainless steel or zinc | Operation, security, long-term reliability |
| Glazing | Double or triple insulated glass, Low-E, laminated or toughened | U-value, solar gain, safety, acoustics |
Thermal breaks are the main difference between a basic and an energy-efficient aluminium window. Without one, the frame conducts heat straight through, making its inner surface cold in winter and prone to condensation. With a wide polyamide break, foam inserts and good glass, whole-window U-values (Uw) of about 1.0 to 1.6 W/m²K are achievable, compared with about 5 W/m²K or more for an old single-glazed, non-broken window. See thermal break aluminium windows and energy-efficient aluminium windows for detail.
Window performance standards by market
Each market tests windows to its own standards. Agree the governing standard and the required classes at enquiry stage, because they decide the profile depth, gaskets, glass and hardware.
| Market | Product standard | Main tests and classes |
|---|---|---|
| Europe / CE marking | EN 14351-1 | Air permeability EN 12207 (class 1 – 4), watertightness EN 12208 (1A – 9A, E), wind resistance EN 12210 (class 1 – 5, A – C), Uw to EN ISO 10077 |
| North America | AAMA/WDMA/CSA 101/I.S.2/A440 (NAFS) | Performance class (R, LC, CW, AW) and grade (PG); tests to ASTM E283 (air), E331/E547 (water), E330 (structure) |
| North America, energy | NFRC 100 / 200 | Rated U-factor and solar heat gain coefficient (SHGC) for energy code compliance |
| Australia / New Zealand | AS 2047 (with AS 1288 for glass) | Serviceability and ultimate wind pressure, water penetration, air infiltration |
| Glass safety (various) | EN 12150, EN 14449, ANSI Z97.1, CPSC 16 CFR 1201 | Toughened and laminated safety glass |
Test results apply to the tested system and size range. A project window larger than the tested specimen, or with a different glass or hardware, may need calculation or additional testing.
Configuring windows for a project
A window quotation is only as good as the information behind it. These are the decisions to make, ideally before tender:
- Type and size of every window, usually listed in a window schedule with references to elevations
- Opening direction and handing, plus restrictors for child safety on upper floors
- Glass build-up: double or triple glazing, Low-E coating, argon fill, laminated or toughened panes where codes require safety glass
- Performance: wind pressure for the building height and location, air and water classes, Uw and acoustic targets
- Finish: colour, coating standard, and whether inside and outside colours differ
- Hardware and accessories: handle style, lock type, insect screens, trickle vents, sill and flashing details
Typical options
- Glazing thickness
- About 24 – 52 mm insulated units in most systems
- Glass types
- Clear, Low-E, solar control, laminated, acoustic, obscure
- Finishes
- Powder coat (AAMA 2604/2605, Qualicoat), anodised (Qualanod), wood-grain
- Colours
- RAL range, dual colour inside/outside
- Screens
- Fixed, sliding, hinged or retractable insect screens
- Packing
- Labelled by building, floor and opening
Matching window systems to building types
| Project type | Priorities | Typical configuration |
|---|---|---|
| Residential developments | Cost control, consistency, fast installation | Sliding and casement windows, double glazing, standard colours |
| Apartments and multi-family housing | Ventilation, child safety, moderate acoustics | Casement or tilt-turn with restrictors, laminated low-level glass |
| Hotels and resorts | Acoustic comfort, uniform appearance, durability | Acoustic laminated glass, slimline frames, PVDF or high-durability powder coat |
| Offices and commercial buildings | Thermal performance, large glass, wind load | Thermally broken casement and fixed windows, ribbon windows integrated with curtain wall |
| Schools and hospitals | Safety, controlled ventilation, low maintenance | Top-hung or tilt windows with restrictors, toughened or laminated glass |
| Coastal projects | Corrosion resistance, high wind and water ratings | High-performance coatings, stainless hardware, higher water classes |
A typical mid-rise apartment block might specify thermally broken casement windows in bedrooms for airtightness, a two-panel sliding door to each balcony, fixed lights in stairwells and top-hung vents in bathrooms, all in one colour and with the same glass build-up so the façade reads as one design.
Where window quality is decided
Extrusion accuracy
Consistent dimensions mean corners close tightly, gaskets seal evenly and hardware fits without adjustment.
Surface finish
Coating thickness, pre-treatment and colour consistency across batches decide how the façade looks in ten years.
Fabrication
Accurate cutting, corner crimping, drainage slots and sealant application decide whether the window leaks.
Glazing
Correct setting blocks and glazing gaskets protect the glass edge and keep the sash square.
Installation
Fixing, packing, sill flashing and perimeter sealing are where many leaks start; good details and instructions matter.
Information needed for an accurate quote
- Project basicsCountry and city, building type and height, and the governing standard (EN 14351-1, NAFS, AS 2047 or other).
- Window scheduleDrawings, window schedule or size list with types, quantities and opening directions.
- SpecificationGlass, hardware, insect screens, finish and colour, and any thermal or acoustic targets.
- LogisticsDestination port, packing and labelling needs, and whether delivery is phased.
- ConfirmationWe confirm the profile series and supply profiles and accessories with documentation and mill certificates, on EXW, FOB, CIF or DAP terms.
References and standards
- EN 14351-1 – Windows and doors: product standard, performance characteristics
- AAMA/WDMA/CSA 101/I.S.2/A440 – North American Fenestration Standard (NAFS)
- AS 2047 – Windows and external glazed doors in buildings (Standards Australia)
- NFRC 100 / NFRC 200 – Procedures for determining fenestration U-factor and SHGC
- EN ISO 10077-1 – Thermal performance of windows, doors and shutters: calculation of thermal transmittance
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
Aluminium (aluminum) window systems: frequently asked questions
Do you supply finished aluminium windows or only profiles?
Profiles only. Metline supplies the extruded profiles, thermal breaks, gaskets and accessories, cut and machined on request; your local fabricator assembles and glazes the windows.
Can you quote from CAD drawings or a window schedule?
Yes. A window schedule or elevations with sizes, types, quantities and opening directions is the best starting point. Add the project location, required standard, glass and finish and we can prepare a configured quotation.
Can one project mix several window types?
Yes, and a system makes this easy. Sliding, casement, tilt-and-turn, fixed and awning windows can share the same colour, glass build-up and hardware family, so the building looks consistent.
When should a project choose thermal break windows?
Whenever the building is heated or air-conditioned and has to meet an energy code, or where condensation on frames is a concern. In mild climates with natural ventilation, non-thermally-broken windows can still be appropriate for cost reasons.
Can windows be built to EN 14351-1, NAFS or AS 2047?
Yes. Tell us the governing standard and the required air, water, wind and thermal classes. The profile system, glass and hardware are then selected to suit, and supporting test documentation is confirmed with the order.
How are windows packed for export?
Frames are protected with film and corner guards, then packed in crates or on stillages labelled by building, floor and opening, with a packing list that matches the window schedule.
Planning windows for a building project?
Send your window schedule, drawings and project location. We will propose a window profile series and quote delivered supply.
