Aluminum Window Specifications: Complete Buyer’s Guide

Buying aluminum windows is not simply a matter of choosing a size, color, and opening style.

Two aluminum windows can look almost identical but perform very differently because of differences in:

• aluminum profiles;

• wall thickness;

• thermal breaks;

• glass;

• hardware;

• sealing systems;

• drainage design;

• surface finishes;

• manufacturing tolerances;

• structural design;

• tested performance.

For distributors, contractors, developers, architects, importers, and building-material buyers, understanding aluminum window specifications is essential before comparing quotations or placing an order.

So, what should a professional aluminum window specification include?

At minimum, buyers should define:

1. Window type and opening configuration

2. Overall dimensions

3. Aluminum profile system

4. Aluminum alloy and temper

5. Profile wall thickness

6. Thermal break requirements

7. Glass configuration

8. Thermal performance

9. Air leakage performance

10. Water penetration resistance

11. Structural and wind-load performance

12. Acoustic performance where required

13. Hardware

14. Gaskets and sealing materials

15. Surface finish and color

16. Screens and accessories

17. Applicable testing standards

18. Packaging and labeling requirements

This guide explains each specification and shows how international buyers can prepare a more professional aluminum window RFQ.

Aluminum Window Specifications at a Glance

Before looking at each parameter individually, here is a practical specification checklist.

The key principle is simple:

Do not purchase aluminum windows based on one specification alone. Evaluate the complete window system.

1. Window Type and Opening Configuration

The first specification is the window opening type.

Common aluminum window types include:

• casement windows;

• sliding windows;

• awning windows;

• tilt-and-turn windows;

• fixed windows;

• single-hung windows;

• double-hung windows;

• combination windows.

The opening method affects:

• ventilation;

• airtightness;

• hardware;

• drainage;

• usable opening area;

• security;

• cleaning;

• space requirements;

• price.

Casement Windows

Casement windows are hinged at the side and typically open inward or outward.

They are often chosen when buyers prioritize:

• strong sealing;

• ventilation;

• thermal performance;

• multi-point locking.

Sliding Windows

Sliding windows move horizontally along a track.

They are frequently selected for:

• wide openings;

• balconies;

• apartments;

• space-saving applications;

• simple operation.

Fixed Windows

Fixed windows do not open.

Because they contain fewer operable joints, they can be useful for:

• large viewing areas;

• façades;

• daylighting;

• applications where ventilation is unnecessary.

Buyer Tip

Your specification should never simply state:

"Aluminum window."

Instead write something such as:

Thermal break aluminum outward-opening casement window with fixed upper light.

The more accurately the configuration is described, the easier it becomes to obtain comparable quotations.

2. Aluminum Alloy and Temper

The aluminum profile itself is one of the main structural components of the window.

Architectural window extrusions commonly use aluminum alloys from the 6000 series.

For example, 6063 aluminum is widely associated with architectural extrusion applications because of its extrusion characteristics and suitability for finishing.

Depending on the system and manufacturer, buyers may encounter designations such as:

• 6063-T5;

• 6063-T6;

• other engineered aluminum alloys and tempers.

ASTM B221 covers aluminum and aluminum-alloy extruded bars, rods, wire, profiles and tubes and includes multiple alloys and tempers.

However, buyers should avoid assuming:

6063-T6 = automatically a high-quality window.

The alloy is only one element.

Actual window performance also depends on:

• profile geometry;

• section dimensions;

• wall thickness;

• mullion design;

• corner connections;

• hardware;

• glass weight;

• window dimensions;

• wind load.

What Should Buyers Ask?

Request:

• aluminum alloy;

• temper;

• profile sectional drawing;

• applicable material standard;

• material certificate where required.

3. Aluminum Profile Series and Frame Depth

You may see window systems described as:

• 50 Series;

• 60 Series;

• 70 Series;

• 80 Series;

• 100 Series;

• 120 Series.

However, these numbers are not universally standardized quality grades.

A "70 Series" from one manufacturer may be completely different from a "70 Series" produced by another manufacturer.

The number often relates in some way to system dimensions or frame depth, but buyers should verify the manufacturer's sectional drawings rather than comparing only series names.

Why Frame Depth Matters

A deeper window system may provide more space for:

• multiple chambers;

• thermal barriers;

• thicker insulating glass;

• stronger reinforcement;

• larger sash configurations;

• more complex sealing systems.

But deeper does not automatically mean better.

A professionally engineered 70 mm system may outperform a poorly designed 90 mm system.

Ask the Supplier For:

• frame depth;

• sash depth;

• profile section drawing;

• glass capacity;

• maximum recommended sash dimensions;

• maximum sash weight.

4. Aluminum Profile Wall Thickness

Profile thickness is one of the most commonly discussed aluminum window specifications.

Buyers may encounter profile thicknesses such as:

• 1.2 mm;

• 1.4 mm;

• 1.6 mm;

• 1.8 mm;

• 2.0 mm;

• thicker project-specific profiles.

However, there is no universal thickness that is best for every aluminum window.

The required thickness depends on:

• window dimensions;

• opening style;

• profile geometry;

• building height;

• wind load;

• sash weight;

• glass weight;

• reinforcement;

• local codes;

• project specifications.

Is a Thicker Aluminum Profile Always Better?

No.

Thickness influences structural behavior, but structural performance depends on the complete profile geometry.

For example, internal webs, chambers, section shape and moment of inertia can significantly affect structural performance.

Therefore:

Do not compare aluminum windows only by profile thickness.

Instead compare:

Wall Thickness + Profile Geometry + Window Size + Wind Load + Tested Structural Performance

Better Buying Question

Instead of asking:

"Is your aluminum 2.0 mm thick?"

ask:

"Can this exact window size and configuration meet our required design pressure, and can you provide supporting calculations or test data?"

That is a much stronger procurement question.

5. Thermal Break vs Non-Thermal Break Aluminum Profiles

Aluminum conducts heat efficiently.

For projects requiring improved thermal insulation, manufacturers often use a thermal break to separate the interior and exterior aluminum sections.

A thermal break helps reduce direct heat transfer through the frame.

Non-Thermal Break Aluminum Window

A conventional non-thermal-break profile has a continuous aluminum connection between the exterior and interior portions of the frame.

These systems may be suitable for:

• mild climates;

• unconditioned spaces;

• certain commercial applications;

• projects with limited thermal requirements.

Thermal Break Aluminum Window

A thermal break system introduces a lower-conductivity material between inner and outer aluminum profiles.

Depending on the system, buyers should investigate:

• thermal barrier material;

• thermal barrier dimensions;

• profile construction;

• connection quality;

• complete-frame thermal performance.

Important

Do not evaluate thermal performance based solely on the width of the thermal break.

The final window performance depends on:

• frame design;

• glazing;

• spacer;

• Low-E coating;

• gas filling;

• sash construction;

• gaskets;

• window size.

The correct target should therefore be whole-window performance, not just "thermal break: yes."

6. Glass Specifications

Glass often represents the majority of the visible window area, making it one of the most important components of aluminum window performance.

A professional specification should define the complete glazing build-up.

Single Glazing

Single glazing consists of one pane of glass.

It may be suitable where:

• thermal performance requirements are low;

• interior applications are involved;

• climate conditions are mild.

Double Glazing

Double glazing uses two panes separated by a cavity.

A specification may look like:

6 mm Tempered + 12A + 6 mm Tempered

or:

6 mm Low-E + 16Ar + 6 mm Clear

The exact configuration should be selected according to project requirements.

Triple Glazing

Triple glazing incorporates three panes with two cavities.

It may be considered for projects with demanding thermal or acoustic requirements.

However, the buyer must also consider:

• total glass thickness;

• glass weight;

• sash weight limitations;

• hinge capacity;

• frame glazing capacity.

7. Tempered Glass Specifications

Tempered glass undergoes heat treatment to increase strength and modify its breakage characteristics.

It is commonly specified in applications requiring safety glazing.

However, safety glass requirements differ by market and location within the building.

Areas such as:

• doors;

• low-level glazing;

• bathrooms;

• stairways;

• large panels;

may be subject to specific safety requirements.

Buyers should therefore provide the applicable project standard instead of simply requesting "tempered glass everywhere."

8. Laminated Glass Specifications

Laminated glass consists of multiple glass layers bonded with an interlayer.

It can be selected for:

• safety;

• security;

• acoustic improvement;

• fall protection;

• impact applications.

A laminated glass specification should identify:

• glass thickness;

• number of layers;

• interlayer type;

• interlayer thickness where required.

Do not simply write:

"Laminated glass."

Specify the actual construction.

9. Low-E Glass Specifications

Low-emissivity, or Low-E, glass uses a coating designed to influence radiant heat transfer.

It is widely used in energy-efficient insulating glass units.

But "Low-E glass" is not a complete specification.

Different Low-E coatings can provide very different:

• U-factor;

• SHGC;

• visible transmittance;

• exterior appearance;

• reflectance.

Therefore, professional buyers should specify the required performance target, not merely request Low-E glass.

10. Insulating Glass Unit Specifications

An IGU specification should ideally include:

Outer Glass + Spacer/Cavity + Inner Glass

For example:

6 mm Low-E Tempered + 16 mm Argon Spacer + 6 mm Clear Tempered

Depending on the project, also confirm:

• total IGU thickness;

• Low-E coating position;

• spacer type;

• gas type;

• edge seal;

• safety glazing;

• laminated layers;

• tint;

• ceramic coating where required.

The frame and glass should always be evaluated together.

A premium IGU installed in a poorly insulated frame will not automatically create a high-performance window.

11. U-Factor and Uw: What Do They Mean?

Thermal transmittance is one of the most important aluminum window performance specifications.

In North America, buyers commonly encounter U-factor.

In many international and European specifications, the term Uw is commonly used for overall window thermal transmittance.

Basic Rule

The lower the U-factor or Uw, the better the window resists heat transfer.

But buyers must confirm what exactly is being measured.

Possible values include:

• Ug = glazing thermal transmittance;

• Uf = frame thermal transmittance;

• Uw = complete window thermal transmittance.

A low Ug value does not necessarily mean the complete window has the same thermal performance.

For North American products, NFRC 100 establishes procedures for determining fenestration product U-factors. NFRC's 2026 document cycle includes ANSI/NFRC 100-2026.

For international projects, ISO 10077-1:2017 provides methods for calculating thermal transmittance of windows and pedestrian doors and remains published and confirmed.

Buyer Tip

Ask:

"Is this U-value for the glass only or for the complete window?"

This simple question prevents many misleading comparisons.

12. Solar Heat Gain Coefficient — SHGC

SHGC measures how much solar heat enters through the complete fenestration product.

Values generally range between 0 and 1.

A lower SHGC means less solar heat enters.

A higher SHGC allows more solar heat through.

Neither is automatically better.

The correct target depends on:

• climate;

• façade orientation;

• building design;

• cooling demand;

• heating demand;

• shading;

• energy code.

For hot climates, reducing unwanted solar heat gain may be important.

For cold climates, the appropriate solar strategy may differ by project.

NFRC provides standardized procedures for determining SHGC and other fenestration energy-performance ratings.

Do Not Specify Low-E Glass by Name Alone

Instead consider specifying:

• target U-factor;

• target SHGC;

• visible transmittance;

• appearance requirements.

13. Visible Transmittance — VT

Visible Transmittance indicates how much visible light passes through a fenestration product.

Generally:

Higher VT = More Visible Light

However, higher is not always automatically better.

Architects may need to balance:

• daylight;

• glare;

• solar heat;

• privacy;

• exterior appearance.

VT should therefore be evaluated together with SHGC and glass appearance.

14. Air Leakage / Air Infiltration

A window may have excellent glass and thermal-break profiles but still perform poorly if air leaks through:

• sash joints;

• corners;

• hardware penetrations;

• tracks;

• gaskets;

• frame joints.

Air leakage testing evaluates how much air passes through a window under specified pressure conditions.

Why Air Leakage Matters

Excessive air leakage can contribute to:

• drafts;

• reduced comfort;

• higher HVAC demand;

• outside noise;

• dust infiltration.

Casement-style systems often rely on compression gaskets.

Sliding systems typically use a different sealing approach because the sash must move along a track.

Neither should be judged purely by window type.

Ask for tested air-leakage performance for the exact window system.

15. Water Penetration Resistance

Water resistance is especially important for:

• coastal projects;

• high-rise buildings;

• rainy climates;

• exposed façades;

• hurricane-prone regions.

A window must manage wind-driven rain without uncontrolled water penetration.

Important system elements include:

• external seals;

• pressure-equalization chambers;

• sill design;

• drainage paths;

• weep holes;

• corner sealing;

• frame installation.

Common Buyer Mistake

Asking:

"Is your window waterproof?"

This question is too vague.

Ask instead:

"At what pressure was this window tested for water penetration resistance, and what exact specimen size was tested?"

Performance should be measurable.

16. Wind Load and Structural Performance

Structural performance is particularly important for large windows and high-rise projects.

The window system may need to resist:

• positive wind pressure;

• negative wind pressure;

• glass loads;

• sash loads;

• operational forces.

In North America, NAFS provides a performance-based framework for windows, doors and skylights. FGIA identifies the 2022 edition as the current NAFS generation, superseding the 2017 edition.

What Determines Wind Resistance?

Wind resistance depends on:

• project location;

• building height;

• façade position;

• window dimensions;

• profile geometry;

• mullion size;

• glass thickness;

• anchoring;

• opening configuration.

Therefore, never assume that one window system can be manufactured at unlimited sizes.

Ask Your Supplier:

• What is the maximum recommended window size?

• What is the maximum sash size?

• What is the maximum sash weight?

• What design pressure can the system meet?

• Is a stronger mullion required?

• What glass thickness is required?

• Can you provide test reports or engineering calculations?

17. Performance Class and Performance Grade

North American specifications may use performance classifications and grades under NAFS.

This is a much more professional basis for product comparison than simply stating:

"Heavy-duty aluminum window."

Terms such as:

• R;

• LC;

• CW;

• AW;

may appear depending on product classification and applicable NAFS edition.

The required product performance should be determined according to the actual building and applicable code.

Important

Do not copy a Performance Grade from another project.

A low-rise house and a high-rise coastal building may require completely different window performance.

18. Acoustic Performance: STC, OITC and Rw

For hotels, apartments, hospitals and buildings near busy transportation routes, acoustic performance can become a major purchasing specification.

Depending on the market, you may encounter:

• STC;

• OITC;

• Rw.

STC

Sound Transmission Class is commonly used for evaluating resistance to certain indoor-type sound frequencies.

OITC

Outdoor-Indoor Transmission Class places greater emphasis on lower-frequency exterior noise and can be useful for traffic, aircraft and urban noise evaluation.

Rw

Weighted Sound Reduction Index is widely used in international specifications.

What Affects Acoustic Performance?

• glass thickness;

• laminated glass;

• asymmetric glazing;

• cavity width;

• seals;

• frame design;

• installation.

Again:

"Double glazing" does not automatically mean excellent sound insulation.

Ask for the tested acoustic rating if sound control is a project requirement.

19. Aluminum Window Hardware Specifications

Hardware is often underestimated during window sourcing.

However, hardware strongly affects:

• operation;

• security;

• sash capacity;

• durability;

• user experience;

• maintenance.

Common components include:

Casement Windows

• handles;

• friction stays;

• hinges;

• multi-point locks;

• corner drives;

• restrictors.

Sliding Windows

• rollers;

• handles;

• locks;

• anti-lift devices;

• stoppers.

Tilt-and-Turn Windows

• multi-point hardware;

• corner transmissions;

• hinges;

• tilt mechanisms;

• locking points.

Hardware Brand vs Hardware Specification

A well-known brand can be useful, but brand alone is not enough.

Confirm:

• exact hardware series;

• sash load capacity;

• corrosion resistance;

• cycle testing where required;

• replacement-part availability;

• warranty.

For coastal applications, corrosion resistance deserves additional attention.

20. Gaskets, Weatherstripping and Sealing

The sealing system plays an important role in:

• airtightness;

• water resistance;

• thermal performance;

• acoustic performance.

Common materials may include:

• EPDM gaskets;

• brush seals;

• silicone;

• other engineered elastomers.

The correct sealing system depends on the type of window.

Casement systems typically use compression seals.

Sliding windows need seals that allow the sash to move.

What to Check

Ask the manufacturer about:

• gasket material;

• number of sealing layers;

• corner treatment;

• replaceability;

• drainage design;

• sealant system.

21. Aluminum Window Surface Finish Specifications

Aluminum can be finished in several ways.

Common options include:

• powder coating;

• anodizing;

• PVDF-type architectural coatings;

• wood-grain transfer finishes.

The finish affects:

• appearance;

• UV resistance;

• corrosion resistance;

• maintenance;

• service life.

Powder-Coated Aluminum Windows

Powder coating offers:

• wide color selection;

• consistent appearance;

• durable surface protection.

Buyers should specify:

• color;

• gloss;

• texture;

• applicable coating performance requirement.

Anodized Aluminum Windows

Anodizing creates an oxide layer on the aluminum surface.

Common appearances include:

• clear;

• bronze;

• black;

• other architectural finishes.

The required anodizing specification should be defined according to the project.

AAMA 2603 vs 2604 vs 2605

For North American architectural aluminum coatings, buyers may encounter:

• AAMA 2603

• AAMA 2604

• AAMA 2605

FGIA describes these as progressively more demanding "good, better, best" categories for factory-applied organic coatings.

Importantly, FGIA released updated AAMA 2603-26, AAMA 2604-26 and AAMA 2605-26 specifications in May 2026.

This is worth checking when reviewing specifications copied from older projects that still reference previous editions.

22. Color Specifications

"Black aluminum window" is still not a complete color specification.

Black can vary considerably between suppliers.

For better consistency, specify:

• RAL color;

• approved physical color sample;

• gloss level;

• texture;

• interior/exterior color combination.

For example:

RAL 9005 Matt Black

is much clearer than:

Black

For large projects, approve a physical sample before production.

23. Window Dimensions

Every custom window requires accurate dimensions.

Your window schedule should include at minimum:

Be clear about whether dimensions refer to:

• overall frame size;

• structural opening;

• finished opening;

• daylight opening.

These are not the same thing.

24. Opening Direction

Opening direction errors are among the most avoidable problems in customized window orders.

Your drawings should clearly identify:

• inward or outward opening;

• left or right handing;

• fixed panels;

• operable panels;

• interior and exterior views.

Do not rely only on phrases such as "left opening."

A supplier and buyer may interpret the orientation from different viewing directions.

Use approved drawings.

25. Mullion and Transom Specifications

Large window assemblies often require:

• vertical mullions;

• horizontal transoms;

• reinforced sections.

Their dimensions and structural properties can be critical for wind-load resistance.

Do not assume that the same standard mullion is suitable for every opening.

For large window walls, ask the manufacturer to evaluate:

• unsupported span;

• mullion dimensions;

• structural reinforcement;

• anchor location;

• wind pressure.

26. Drainage Specifications

A well-designed window must manage water that reaches the frame.

Important elements may include:

• drainage cavities;

• drainage holes;

• sill chambers;

• pressure equalization;

• external drainage paths.

This is particularly important for sliding window systems.

When evaluating samples, inspect the bottom frame carefully.

A visually attractive profile with poor drainage can create serious problems after installation.

27. Insect Screen Specifications

Screens should be specified separately rather than assumed to be included.

Options may include:

• fixed screens;

• removable screens;

• sliding screens;

• retractable screens;

• stainless-steel security mesh.

Confirm:

• mesh material;

• frame material;

• color;

• installation method;

• removable or fixed design.

28. Security Specifications

Window security may involve:

• multi-point locks;

• reinforced locking points;

• anti-lift devices;

• security laminated glass;

• restricted opening;

• keyed handles;

• burglar-resistance requirements.

Do not judge security solely by the number of locks.

The frame, glass, hardware and installation must work as a complete system.

29. Condensation Performance

Condensation can occur when interior surface temperatures fall below the dew point of indoor air.

Factors affecting condensation include:

• outdoor temperature;

• indoor temperature;

• indoor humidity;

• aluminum frame thermal performance;

• glass performance;

• spacer design;

• installation.

Thermally broken frames and high-performance glazing can improve interior surface temperatures, but no ordinary window can guarantee zero condensation under every humidity and climate condition.

Therefore, specifications should focus on measurable system performance.

30. Window Tolerances and Manufacturing Accuracy

Custom windows require dimensional consistency.

Buyers should establish acceptable tolerances for critical dimensions according to:

• applicable standards;

• system design;

• project requirements.

Quality inspection can include:

• overall dimensions;

• diagonal measurements;

• frame squareness;

• sash alignment;

• mullion position;

• glass dimensions;

• hardware positioning.

A 1 mm issue on a small component may be insignificant.

The same error repeated across hundreds of customized construction openings may become a project problem.

31. Aluminum Window Standards by Market

There is no single worldwide aluminum window standard.

Requirements vary according to market.

North America

Important standards and organizations may include:

NAFS

AAMA/WDMA/CSA 101/I.S.2/A440 provides a performance-based specification for windows, doors and skylights.

The current NAFS generation is the 2022 edition, with an October 2023 revision available.

NFRC

NFRC provides standardized methods for evaluating energy-performance characteristics such as:

• U-factor;

• SHGC;

• Visible Transmittance;

• condensation-related metrics.

NFRC published its 2026 technical document cycle in 2026.

ASTM

Various ASTM standards may be referenced for materials and performance testing depending on the project.

For example, ASTM B221 covers aluminum-alloy extruded profiles and tubes.

32. European Market

European window specifications may reference standards including:

EN 14351-1 for performance characteristics of windows and external pedestrian doorsets.

EN 14351-1:2006+A2:2016 identifies material-independent performance characteristics applicable to windows and external pedestrian doorsets.

Thermal calculations may also reference:

EN ISO / ISO 10077-1

for thermal transmittance calculations.

However, European conformity requirements can vary depending on:

• product;

• project;

• country;

• applicable regulation;

• intended use.

Always verify current project requirements before manufacturing.

33. Other International Markets

Australia, New Zealand, the Middle East, Canada, Japan and other markets have their own building and product requirements.

Buyers should therefore tell the manufacturer:

1. Destination country
2. Project location
3. Building type
4. Building height
5. Required standard
6. Required performance

before requesting a final window specification.

Never assume that a window successfully sold in one country is automatically suitable for another.

34. Product Specification vs Tested Performance

This distinction is extremely important.

A supplier might tell you:

Profile thickness: 2.0 mm
Glass: Double Low-E
Thermal break: 24 mm
Premium hardware

These are component specifications.

They do not automatically prove:

• U-factor;

• air leakage;

• water resistance;

• wind-load resistance;

• sound insulation.

Performance should ideally be demonstrated using relevant:

• laboratory test reports;

• certification;

• calculations;

• project engineering.

A professional buyer should therefore evaluate both:

Component Specifications

What the window is made from.

AND

Performance Specifications

What the complete window can actually achieve.

That distinction is one of the most important concepts in aluminum window procurement.

35. How to Compare Two Aluminum Window Quotations

Imagine Supplier A and Supplier B both quote a:

1500 × 1500 mm Aluminum Casement Window

Supplier A: $220
Supplier B: $310

Does this mean Supplier A is cheaper?

Not necessarily.

Compare:

They are fundamentally different products.

Correct Comparison Method

Normalize specifications first.

Ask every shortlisted manufacturer to quote:

the same dimensions + same profile requirement + same glass + same hardware + same finish + same tested performance + same Incoterm.

Only then compare prices.

36. Sample Aluminum Window Specification Sheet

Here is a simple example buyers can use as a starting point.

Project Information

Project: Residential Development
Destination: [Country]
Application: Exterior Residential Windows

Window

Type: Outward-Opening Casement
Overall Size: According to Window Schedule
Opening Direction: According to Approved Shop Drawings

Aluminum

Material: Extruded Aluminum
Alloy/Temper: To approved system specification
Profile: Thermal Break System
Frame Depth: Supplier to state
Wall Thickness: Supplier to state and meet required structural performance

Thermal Barrier

Type: Structural Thermal Break
Material: Supplier to state
Width: Supplier to state

Glass

Configuration: Double Insulated Glazing
Outer Pane: Tempered Low-E Glass
Cavity: Insulated Spacer, gas filling where specified
Inner Pane: Tempered/Clear or Laminated according to project

Performance

U-Factor/Uw: Project requirement
SHGC: Project requirement
Air Leakage: Project requirement
Water Penetration: Project requirement
Design Pressure: Project requirement
Acoustic Rating: Project requirement if applicable

Hardware

Lock: Multi-Point
Handle: Approved Type
Hinge/Friction Stay: Sized for sash load
Finish: Match frame

Seals

Gaskets: Compatible weather-resistant system
Sealant: Project-approved material

Finish

Type: Powder Coating / Approved Architectural Coating
Color: RAL ______
Gloss: ______

Accessories

Insect Screen: Yes / No
Restrictor: Yes / No

Documentation

Supplier shall provide where applicable:

• profile drawings;

• glass specification;

• hardware datasheet;

• test reports;

• shop drawings;

• finish sample;

• warranty.

This is far more useful than simply sending:

"Please quote aluminum casement windows."

37. Aluminum Window RFQ Checklist

Before requesting a quotation from an aluminum window manufacturer, prepare the following:

Project Information

• Destination country

• Project location

• Building type

• Building height

• Quantity

Window Information

• Window schedule

• Width and height

• Window type

• Opening direction

• Fixed/operable configuration

Aluminum

• Profile system

• Frame depth requirement

• Wall thickness requirement

• Alloy/temper if specified

• Thermal break requirement

Glass

• Single/double/triple glazing

• Glass thickness

• Tempered glass

• Laminated glass

• Low-E coating

• Gas filling

• Safety requirements

Performance

• U-factor/Uw

• SHGC

• Air leakage

• Water penetration

• Wind/design pressure

• Acoustic performance

Hardware

• Hardware brand or performance level

• Locking system

• Handle

• Restrictor

• Corrosion requirement

Finish

• Powder coating/anodizing/other

• RAL color

• Gloss

• Texture

• Coating standard

Accessories

• Screens

• Flashing

• Subframes

• Installation accessories

Commercial Requirements

• MOQ

• Sample

• Production lead time

• Packaging

• Warranty

• Incoterm

• Destination port

This checklist makes quotations significantly easier to compare.

38. Common Aluminum Window Specification Mistakes

Mistake 1: Specifying Only Aluminum Thickness

Thickness alone cannot define window quality.

Consider complete structural performance.

Mistake 2: Specifying "Double Glass" Without Construction

"Double glass" could represent many different configurations.

Write the complete glass build-up.

Mistake 3: Specifying "Low-E" Without Performance

Different Low-E coatings provide different solar and thermal characteristics.

Define U-factor and SHGC targets.

Mistake 4: Confusing Ug With Uw

Ug refers to glazing thermal performance.

Uw relates to the complete window.

Do not compare them directly.

Mistake 5: Assuming a Thermal Break Guarantees Energy Efficiency

Thermal breaks help, but glazing, profile design, seals and system construction also matter.

Mistake 6: Ignoring Wind Load

Large windows should not be priced or manufactured before structural requirements are evaluated.

Mistake 7: Ignoring Hardware Load Capacity

Larger glass panels create heavier sashes.

Hardware must be sized accordingly.

Mistake 8: Using Only a Color Name

"Black" or "grey" is too vague.

Use an approved RAL code or physical sample.

Mistake 9: Failing to Specify Opening Direction

Always confirm opening direction through drawings.

Mistake 10: Comparing Prices Before Normalizing Specifications

The lowest-priced window may simply contain lower-cost components.

Compare like-for-like specifications.

39. What Are the Most Important Aluminum Window Specifications?

If you have limited time, focus first on these eight items:

1. Window Type

Determines operation and basic system design.

2. Window Dimensions

Determines structural and manufacturing requirements.

3. Profile System

Determines frame design and glass capacity.

4. Glass Configuration

Has a major impact on energy, safety and acoustics.

5. Thermal Performance

Evaluate complete-window U-factor/Uw where relevant.

6. Air / Water / Wind Performance

Determines weather and structural performance.

7. Hardware

Determines operation, security and durability.

8. Applicable Standards

Determines whether the product is suitable for the destination market.

If these eight items are unclear, the quotation is probably not ready for meaningful comparison.

Frequently Asked Questions About Aluminum Window Specifications

What is the standard thickness of an aluminum window profile?

There is no single universal aluminum window profile thickness.

Thickness varies according to profile design, window size, application, building height, glass weight, wind pressure and applicable standards.

Buyers should select thickness according to structural requirements rather than assuming that one thickness is suitable for every window.

Is 1.4 mm aluminum good for windows?

It may be suitable for certain window systems and applications, but thickness alone cannot determine whether a window is good or bad.

You also need to consider:

• profile geometry;

• window dimensions;

• wind load;

• glass;

• mullion design;

• tested structural performance.

Is 2.0 mm aluminum always better than 1.4 mm?

Not necessarily.

A properly engineered thinner profile can sometimes provide better structural performance than a poorly designed thicker profile.

Compare system performance rather than material thickness alone.

What aluminum alloy is commonly used for window profiles?

6000-series aluminum alloys are commonly used for architectural extrusion applications, and 6063 is frequently encountered in window and door systems.

The exact alloy and temper should be selected according to the manufacturer's engineered system and relevant material requirements.

What is the best glass thickness for aluminum windows?

There is no universal glass thickness.

The required glass depends on:

• panel dimensions;

• wind pressure;

• building height;

• safety requirements;

• thermal requirements;

• acoustic requirements;

• frame capacity.

A professional supplier should evaluate the glass and frame as one system.

What is a good U-factor for aluminum windows?

There is no universal "good" U-factor for every project.

The required value depends on:

• local energy codes;

• climate zone;

• building type;

• project performance target.

The general rule is that lower U-factor means lower heat transfer.

Always compare whole-window U-factor rather than glass-only U-value.

What is SHGC in aluminum windows?

SHGC stands for Solar Heat Gain Coefficient.

It represents the fraction of solar heat that enters through a fenestration product.

A lower SHGC reduces solar heat gain, while a higher SHGC allows more solar energy through.

The appropriate value depends on climate and building design.

What specifications should I send an aluminum window manufacturer?

At minimum send:

• window schedule;

• dimensions;

• opening type;

• opening direction;

• profile requirements;

• glass;

• thermal requirements;

• air/water/wind requirements;

• hardware;

• color;

• quantity;

• destination market.

Providing complete information improves quotation accuracy.

What is more important: profile thickness or tested performance?

For professional procurement, tested performance is generally more meaningful.

Profile thickness is an important component specification, but buyers ultimately need a window that meets structural, thermal, air and water requirements.

Should I ask for aluminum window test reports?

For projects with defined performance requirements, yes.

Ask for relevant test reports and verify:

• manufacturer;

• product/system;

• tested dimensions;

• opening style;

• glass configuration;

• test standard;

• test result;

• testing laboratory.

A report for one window system does not automatically apply to every custom configuration.

How can I compare aluminum window suppliers?

Create one standardized RFQ and send the same specification to every supplier.

Then compare:

• complete technical configuration;

• test documentation;

• manufacturing capability;

• quality control;

• engineering support;

• warranty;

• delivery;

• price.

This produces a much more reliable supplier comparison than asking each manufacturer for its "best window."

Final Aluminum Window Specification Checklist for Buyers

Before confirming an aluminum window order, make sure you can answer these questions:

What window type am I buying?

What are the exact dimensions?

Which aluminum profile system will be used?

What is the profile section and wall thickness?

Is the frame thermally broken?

What is the exact glass composition?

What is the complete-window U-factor/Uw?

What SHGC is required?

What air-leakage performance is required?

What water resistance is required?

What design wind pressure must the window resist?

What acoustic performance is required?

Which hardware will be installed?

Which gaskets and seals will be used?

What surface finish and color are required?

What standards must the product meet?

Have the shop drawings been approved?

Have relevant test reports been reviewed?

If these questions are answered clearly, your supplier can provide a much more accurate product and quotation.

Specify the Complete Window, Not Just the Aluminum Profile

The most important lesson for aluminum window buyers is this:

A window is a system, not a collection of individual specifications.

A thicker aluminum profile does not automatically guarantee better performance.

A thermal break does not automatically guarantee excellent insulation.

Double glazing does not automatically guarantee good acoustics.

Low-E glass does not automatically guarantee the correct SHGC.

And a famous hardware brand cannot compensate for poor frame design.

Successful window procurement requires the complete combination of:

Profile + Glass + Thermal Break + Sealing + Hardware + Drainage + Structural Design + Manufacturing + Installation

to meet the project's requirements.

Custom Aluminum Window Specifications from Wintenic

Wintenic provides customized aluminum window and door solutions for distributors, wholesalers, contractors, developers and international building projects.

With more than 20 years of industry experience, Wintenic supports multiple aluminum window systems including casement, sliding, hung and fixed windows, as well as OEM and ODM customization.

Customization options can include:

• window dimensions;

• aluminum profile systems;

• opening configurations;

• thermal break systems;

• glass combinations;

• Low-E insulating glass;

• laminated and tempered glass;

• hardware;

• colors;

• surface finishes;

• screens;

• project packaging;

• OEM requirements.

Need Help Preparing Your Aluminum Window Specification?

Send Wintenic your:

1. Window schedule or architectural drawings
2. Project location
3. Required window dimensions
4. Opening styles
5. Glass requirements
6. Thermal-performance target
7. Wind-load requirements
8. Hardware requirements
9. Color and finish
10. Quantity

Our team can review your requirements and recommend a suitable aluminum window configuration for your market or project.