Aluminium Sliding Windows

What is Aluminium Window?

Aluminium windows are made from extruded aluminium alloy 6063-T5 profiles. The aluminium is melted, mixed with alloying elements (silicon, magnesium), extruded through dies into custom profile shapes, then heat-treated for strength. The profiles are surface-treated (anodised or powder-coated) for corrosion / weather resistance.

Aluminium windows are stronger per unit weight than steel, never rust, never need painting, and offer the slimmest profile width (45–55 mm) in the market — giving maximum glass area. Modern thermal-break aluminium offers competitive thermal performance with UPVC.

Types of Aluminium Windows

Type	Opening Style	Use
2-Track Sliding	Two horizontally sliding panes	Standard residential
3-Track Sliding	Three panes, more ventilation	Large openings
4-Track Sliding	Four sliding panes	Very large openings
Sliding with Fixed Panel	One side fixed	Cost saving option
Casement Window	Side-hinged opening outward / inward	Bathrooms, kitchen, full opening
Top-Hung / Awning	Hinged at top	Bathroom ventilator
Bottom-Hung / Hopper	Hinged at bottom, tilts in	Basement, ventilation
Fixed (Picture)	Non-opening, large glass	View-only
Louvered Window	Multiple horizontal blades	Ventilator, traditional
Slide & Fold (Bi-Fold)	Concertina-folding	Patio, balcony
Curtain Wall (Glazing)	Full glass facade	Commercial buildings
Structural Glazing	Frameless exterior look	Commercial / luxury
Spider Glazing	Bolt-fixed glass	Atrium, mall
Tilt & Turn	Premium opening modes	Premium homes

Aluminium Alloy Grades

Grade	Composition	Use
6063-T5	Al-Mg-Si	Standard window / door profiles
6063-T6	Al-Mg-Si	Heavier duty profiles
6061-T6	Al-Mg-Si-Cu	Structural members
6082-T6	Al-Mg-Si-Mn	High strength applications
2014 / 2024	Al-Cu	Aerospace (not used in windows)
7075	Al-Zn	Aerospace

Profile Series & Specifications

Profile Series	Width / Depth	Use
20 Series (Eco)	20 mm wide rail	Bathroom, light internal
27 Series	27 mm	Standard residential
40 Series	40 mm	Standard 2-track sliding
54 Series	54 mm	3-track sliding
60 Series	60 mm	Premium residential
70 / 80 Series	70–80 mm	Thermal break / premium
100 Series	100 mm	Large commercial / curtain wall

Profile Wall Thickness Class

Class	Wall Thickness	Use
Class A (Heavy)	> 2.5 mm	Premium, large openings, commercial
Class B (Medium)	1.8 – 2.5 mm	Standard residential
Class C (Light)	1.2 – 1.8 mm	Budget residential
Below Class C	< 1.2 mm	Avoid — structurally weak

Surface Finishes

Anodised Aluminium

Electrochemical oxidation creates thick oxide layer (10–25 microns)
Natural metallic look (silver, bronze, gold, black)
Extremely durable (25–50 years)
Resistant to corrosion, weathering, scratches
Most common Indian finish
Cost: +15% over mill finish

Powder Coated Aluminium

Electrostatic application of polyester powder (60–80 microns)
Cured at 200°C for hard durable coating
Any RAL colour available
15–25 year warranty against fading
Excellent for coastal areas
Cost: +20% over mill finish

Wood Grain / Sublimation Finish

Premium wood-grain look transferred to aluminium surface
Combines aluminium strength with wood aesthetic
10–15 year colour warranty

PVDF (Polyvinylidene Fluoride) Coating

Premium chemical-resistant coating
Architectural metallic / pearl finishes
30+ year colour warranty
Commercial / luxury use

Mill Finish

Untreated raw aluminium
Cheapest option
Oxidises to dull grey
Industrial / internal use only

Physical Properties

Property	Aluminium 6063-T5
Density	2,700 kg/m³
Tensile Strength	185 – 240 MPa
Yield Strength	145 – 215 MPa
Elongation	8 – 12%
Modulus of Elasticity	70 GPa
Hardness (Brinell)	60 – 75 HB
Thermal Conductivity (raw Al)	200 W/m.K (very high)
U-value (Window, no thermal break)	5.0 – 6.5 W/m²K
U-value (Window, thermal break)	2.5 – 3.8 W/m²K
Linear Thermal Expansion	23.4 × 10⁻⁶ /°C
Melting Point	610 °C
Corrosion Resistance	Excellent (anodised / coated)
UV Resistance	Excellent
Sound Reduction (single glass)	25 – 32 dB
Lifespan (Frame)	30 – 50 years
Lifespan (Hardware)	10 – 20 years
Operating Temperature	−40 to +80 °C

Thermal Break Technology

Standard aluminium is highly conductive (200 W/m.K) — making windows cold in winter and hot in summer. Thermal Break aluminium separates the interior and exterior aluminium with a non-conductive polyamide (nylon) strip 20–40 mm wide.

Type	Construction	U-value
Standard Aluminium	Solid aluminium profile	5.0 – 6.5 W/m²K
Thermal Break (Simple)	Polyamide strip 20 mm	3.5 – 4.0 W/m²K
Thermal Break (Premium)	Polyamide 30–40 mm + foam	2.5 – 3.0 W/m²K
Thermal Break (Passive House)	40+ mm polyamide multi-chamber	1.4 – 2.0 W/m²K

Thermal Break aluminium is 30–50% more expensive than standard aluminium but reduces AC energy by 20–30%, prevents condensation in monsoon, and improves sound insulation. Required for premium homes and commercial buildings seeking GRIHA / LEED certification.

Top Indian Brands

Jindal Aluminium — India’s #1 extrusion company, residential profiles
Hindalco / Eternia — Premium residential window systems
Aluminco (Australia) — Premium imported
Schueco India — German premium
Aluplast (German) — Combined UPVC and aluminium
AIS Windows — Asahi Glass with aluminium frames
Pennar Industries — Industrial / commercial
Bhoruka Aluminium — Indian extruder
Saraswati Aluminium — Indian extruder
National Aluminium (Nalco) — Public sector
Reynaers (Belgium) — European premium
Kawneer (Arconic) — American commercial
Technal — French premium
YKK AP — Japanese commercial

Aluminium vs UPVC Windows

Parameter	Aluminium	UPVC
Profile Width (visible)	Slim 45–55 mm	Wider 70–88 mm
Glass Area / Window Area	~85%	~70–75%
Weight	Lighter	Heavier (with steel reinforcement)
Thermal Insulation	Poor (3.5–6.5 W/m²K without break)	Excellent (1.3–2.5 W/m²K)
Thermal Break Version	Available (2.5–3.0 W/m²K)	Built-in
Sound Insulation	Good (25–35 dB)	Better (30–45 dB)
Strength	Excellent	Excellent (with steel)
Maintenance	Low	Very low
Corrosion	None (anodised / coated)	None
UV Resistance	Excellent	Excellent (UV stabilised)
Colour Options	Unlimited (powder coat)	Limited (mostly white / brown)
Premium Look	Modern minimal	Modern (chunky)
Lifespan	30 – 50 years	25 – 50 years
Customisation	Excellent (on-site cut)	Limited (factory only)
Cost (Rs/sqft, all-in)	250 – 900	500 – 1500
Best For	Slim sightlines, design, commercial	Energy efficient homes, noisy areas

Hardware Components

Sliding Window Hardware

Tandem rollers (single or double wheel)
Adjustable rollers (height control)
Crescent / hook lock
Bottom track / runner
Anti-lift block / device
Brush seals / weather strips
Stainless steel mosquito mesh (optional)
Window cleaning clip

Casement Window Hardware

Friction stay / scissor hinge
Espagnolette lock
Handle with key option
Striker plates
Limiter / restrictor
Hinge protectors

Premium / Tilt-Turn Hardware

Multi-point lock (Roto / Maco / Siegenia)
Anti-burglary cam locks
Tilt drive gear
Tilt limiter
Soft-close mechanism

Standard Sizes & Configurations

Application	Standard Size (mm)
Bathroom Window	600 x 600 / 900 x 600
Kitchen Window	1200 x 900 / 1500 x 900
Bedroom Window	1500 x 1200 / 1800 x 1200
Living Room	2400 x 1500 / 3000 x 1500
Balcony / French	2400 x 2100 / 2700 x 2100
Ventilator (Top)	900 x 450 / 1200 x 450
Picture / Fixed	Custom up to 4000 x 2500
Curtain Wall (commercial)	Floor-to-ceiling unlimited

Step-by-Step Installation

Site Measurement: Accurate wall opening dimensions (verify squareness)
Order Manufacturing: Profiles cut to size in factory or site
Aluminium Frame Assembly: Mitre cut corners at 45°, screw + cleat joints
Wall Anchors: Drill anchor holes at 600 mm c/c in opening
Frame Insertion: Lift frame into opening
Levelling: Use wooden packers for plumb, level, square
Fixing: Fix with masonry screws (75 mm)
Sealing: Apply silicone / PU sealant in 8–12 mm gap
Insertion of Glass: Use EPDM gaskets for sealing
Glazing Bead: Snap glazing bead to hold glass
Sash / Shutter Installation: Hang sashes on rollers / hinges
Hardware: Install locks, handles, rollers
Test Operation: Smooth open / close, lock test
Final Sealing: Silicone bead exterior & interior
Cleaning: Remove protective film, clean glass & frames

Where to Use Aluminium Windows

Best For:

Standard residential windows (most common Indian choice)
Commercial buildings, offices
Curtain wall facades
Apartment buildings (cost-effective)
Industrial buildings
Schools, hospitals
Shop fronts
Coastal areas (with proper coating)
Premium homes (with thermal break)
Slim sightline aesthetic preference
Large window sizes (lighter than UPVC)
Custom shapes / sizes
Budget-conscious projects
Mass housing
Renovation (lighter / easier to install)

Less Optimal For:

Heavy AC homes (use thermal break or UPVC)
Highway / airport noise areas (use UPVC)
Extreme cold climates (use thermal break)
Heritage homes (use wooden windows)
Passive house / Net Zero (use thermal break or UPVC)

Advantages

Slim sightline (maximum glass area)
Lightweight (vs UPVC + steel reinforcement)
Excellent strength-to-weight ratio
Never rusts / corrodes (with treatment)
Termite, rot, mould proof
Long lifespan (30–50 years)
UV stable (anodised / coated)
Wide colour options (powder coat)
Recyclable (eco-friendly)
Faster installation than UPVC
Custom on-site cutting possible
Large openings possible (curtain walls)
Lower upfront cost than UPVC
Easy maintenance (just wipe clean)
Modern minimalist aesthetic
Available with thermal break
Suitable for fire-resistant applications
Compatible with all glass types
Wide hardware compatibility
Excellent for renovation (lightweight)

Disadvantages

Poor thermal insulation (without thermal break)
Lower sound insulation than UPVC
Higher condensation (cold bridge in non-thermal break)
Surface dents on impact
Hardware quality varies
Powder coating can scratch
Anodising thickness varies by source
Cheap variants may have thin walls (deformation risk)
Counterfeit / low-grade profiles common
Galvanic corrosion if in contact with steel
Higher U-value than wood
Requires EPDM gaskets (don’t use cheap PVC)
Heavy condensation issue in monsoon
Cold to touch in winter
Frame can transfer heat (summer)
Roller life 7–10 years (sliding)

Cost (Approximate, Indian Market — per sqft, all-in)

Configuration	Cost (Rs / sqft)
Basic 2-Track Sliding (Class C profile, 5 mm glass)	250 – 400
Standard 2-Track Sliding (Class B, 5 mm glass)	350 – 550
Premium 2-Track Sliding (Class A, anodised)	500 – 750
3-Track Sliding (Standard)	400 – 700
Casement Window (Standard)	400 – 650
Casement (Powder Coated)	500 – 800
Casement with DGU (Sound proof)	700 – 1,100
Top Hung / Awning	450 – 700
Tilt & Turn (Thermal Break)	900 – 1,500
Slide & Fold (Bi-fold)	1,200 – 2,000
Lift & Slide Patio Door	1,500 – 2,800
Fixed Picture Window	250 – 500
Curtain Wall (Commercial)	700 – 1,800
Structural Glazing	1,000 – 2,500
Thermal Break Premium	+300 – 800 / sqft over standard
Powder Coating (RAL colour)	+20% over anodised
Wood-Grain Finish	+25–40% over base
SS Pleated Mosquito Net	+150 – 300 / sqft

Standard Window Costs

Window Size	Standard Aluminium (Rs)	Premium Aluminium (Rs)
900 x 600 (bathroom)	1,800 – 3,200	3,500 – 5,500
1500 x 900 (kitchen)	3,800 – 6,500	7,000 – 11,000
1500 x 1200 (bedroom)	5,000 – 9,000	9,500 – 15,500
2400 x 1500 (living)	10,000 – 17,000	18,000 – 32,000

Tests on Aluminium Windows

Profile Dimensional Tolerance — IS 1948
Profile Wall Thickness Test
Tensile / Yield Strength — IS 1608
Hardness Test (Brinell) — IS 1500
Anodising Thickness Test — IS 1868 (eddy current)
Anodising Sealing Test (Drop Test)
Powder Coating Thickness — ISO 2360
Salt Spray Test — ASTM B117 (1000 hr)
QUV Weathering Test — ASTM G155
Air Permeability — EN 1026
Water Tightness — EN 1027
Wind Load Resistance — EN 12211 / IS 1948
Operational Forces — EN 12046
Mechanical Endurance — EN 12400
U-value — EN ISO 10077
Sound Reduction — EN ISO 717

Best Practices

Choose Class B (1.8–2.5 mm) or Class A (> 2.5 mm) wall thickness
Use 6063-T5 alloy (standard) or T6 (heavy duty)
Insist on anodising thickness 15–25 microns
Use polyester powder coating > 60 microns
For AC homes / extreme climate, choose thermal break
Use EPDM gaskets (not cheap PVC) for waterproofing
Use stainless steel screws / fasteners
For sliding, choose tandem (dual-wheel) rollers
For large windows, use reinforcement
Maintain 10 mm gap around frame for sealant
Apply silicone exterior + interior
For coastal areas, choose powder coated over anodised
Use 5 mm float glass minimum (8 mm for large)
Use toughened glass at low heights / balconies (safety)
Maintain rollers / hinges with light oil annually
Clean tracks frequently to prevent dust accumulation
Choose ISI-marked / BIS-certified profiles
Buy from authorised dealer with warranty
Get installer warranty + manufacturer warranty

Applicable Standards

Standard	Description
IS 1948	Aluminium Doors, Windows & Ventilators — Specification
IS 733	Wrought Aluminium & Aluminium Alloys, Bars, Rods & Sections
IS 737	Wrought Aluminium & Aluminium Alloys, Sheets, Strips
IS 1285	Wrought Aluminium & Aluminium Alloys, Extruded Round Tube
IS 1868	Anodic Coatings on Aluminium — Specification
IS 6021	Anodic Oxidation Coatings — Standard Method
IS 4994	Powder Coatings for Aluminium — Specification
EN 12020	Aluminium & Aluminium Alloys — Extruded Precision Profiles
EN 12206	Powder Coatings on Aluminium & Aluminium Alloys (Qualicoat)
EN 14351-1	Window & External Pedestrian Door Standard
EN 1026 / 1027 / 12211	Air, Water, Wind Performance Testing
EN 12046 / 12400	Operating Forces / Mechanical Durability
EN ISO 10077-1 / 2	Thermal Performance of Windows
Qualicoat / Qualanod	European quality marks for coating / anodising

Conclusion

Aluminium sliding windows remain India’s most popular window system, balancing cost, durability, slim sightlines and design flexibility. With proper selection (Class B/A profile, anodising or powder coat, quality hardware), aluminium windows last 30–50 years with minimal maintenance.

Recommendations:

Standard residential: Class B 2-track sliding with 5 mm float (Rs 350–550/sqft)
Premium residential: Class A casement with DGU (Rs 700–1100/sqft)
Energy-efficient AC homes: Thermal break + Low-E DGU (Rs 900–1500/sqft) — or upgrade to UPVC
Commercial / Office: Curtain wall or large sliding (Rs 700–1800/sqft)
Coastal areas: Powder coated with marine-grade hardware
Slim sightline preference: Aluminium beats UPVC (45 vs 70 mm)
Budget housing: Class C aluminium (Rs 250–400/sqft)
Premium balcony patio: Slide & fold or lift & slide
Heritage homes: Use wooden windows
Noisy locations: UPVC superior to aluminium

For higher thermal & sound performance, consider UPVC windows; for security & main entrance, see FRP / steel doors; for internal doors, see flush doors or WPC / PVC doors.

Aluminium Sliding Windows — Complete Guide