Executive Summary

Selecting the appropriate window system for a building project is a specification decision that directly impacts energy performance, occupant comfort, structural integrity, and long-term operational costs. For architects, facade consultants, developers, and procurement professionals, understanding the technical distinctions between window types — and how those distinctions map to project requirements — is essential for delivering buildings that perform as designed.

This guide provides a technical overview of the major window types used in contemporary residential and mixed-use construction globally. Each section covers the operating principle, performance characteristics, typical applications in building projects, and real product specifications from EEHE's certified product range. Performance data cited is based on testing conducted at Intertek and other accredited laboratories.

About EEHE: Founded in 2008, Guangdong EEHE Doors & Windows Technology Co., Ltd. serves 32+ countries and regions with 427+ authorized dealers, a 53,344 m² manufacturing base, and over 3 million households served globally. The company holds NFRC, CSA, and CE certifications, plus NAFS-80 (North American Fenestration Standard) test reports. EEHE operates a post-doctoral research workstation and maintains university collaborations with Tsinghua University and Harbin Institute of Technology, supported by Italian production technology and German automated manufacturing equipment.

1. Casement Windows (Hinged Operable)

Casement windows are side-hinged sashes that open outward or inward. They are the dominant window type in European and North American residential construction for buildings up to 7 storeys, valued for their compression-seal performance and unobstructed views.

Operating Principle

A casement sash attaches to the frame via butt hinges or friction stays. Multi-point locking mechanisms engage mushroom-head pins around the sash perimeter, compressing the gasket against the frame. This compression seal is inherently tighter than the wool-pile or brush seals used in sliding windows, which wear over time and allow air infiltration.

Inward-Opening (Tilt-and-Turn)

• Both glass surfaces accessible from indoors — significant maintenance advantage for multi-storey projects
• Wind pressure reinforces the seal against the frame
• Tilt position provides safe micro-ventilation without security compromise
• Preferred for high-rise residential applications (above 7 storeys)

EEHE Product Reference: NYK VOGUE Series — Double inward-opening casement with dual sash

Outward-Opening

• No interior space loss — sash opens outward
• Superior rain deflection when paired with hood or overhang
• Can combine with top-hung (awning) function for rain-safe ventilation

EEHE Product Reference: Rhine Time Series (110 mm frame)

EEHE Product Reference: Seine River Series (80 mm outward opening)

2. Sliding Windows (Horizontal Sliding)

Sliding windows open by gliding one sash horizontally past another on tracks. They are specified where swing clearance is limited — corridors, balconies, terraces, and kitchen openings — and for large panoramic openings requiring multi-panel configurations.

Standard Sliding Windows

• No projection beyond the building envelope
• Simple single-handed operation
• Cost-effective for large openings
• Wool-pile sealing — suitable for mild-to-moderate climates

Thermal Break Sliding Windows

For projects in temperature-extreme climates, thermal break sliding windows incorporate a polyamide (PA66) strip between interior and exterior aluminum profiles, interrupting the thermal bridge. This significantly reduces heat transfer through the frame assembly.

EEHE Product Reference: Sunshine Coast Series — Thermal Break Sliding Window

Design Innovations:

• Embedded interlocking frame-sash structure — reduces gaps, improves thermal/acoustic performance
• Stepped track design — higher outer rail, lower inner rail — eliminates standing water infiltration
• Anti-derailment rollers — U-shaped typhoon-rated upper rollers with adjustment mechanism
• Concealed frame drainage — prevents wind-driven rain backflow
• Optional integrated security grille + drying rack (3-track configuration)

Suspended (Lift) Sliding Windows

Suspended sliding systems (also called lift-and-slide or floating sashes) use a specialized roller system where the sash embeds fully into the frame, creating a clean, modern appearance with improved sealing over standard sliders.

EEHE Product Reference: Champs-Elysees Series — Suspended Sliding Window

3. Drift Windows (Slide-and-Tilt Hybrid)

Drift windows (also called slide-and-tilt or push-sliding windows) are an innovative hybrid combining the space-saving horizontal slide of a sliding window with the multi-point compression sealing and tilt-ventilation of a casement. They are increasingly specified in multi-residential projects where both security and space efficiency are critical.

How Drift Windows Work

A specialized track-and-hinge hardware system — typically from OEM partners such as Opacle — allows the sash to slide horizontally for full opening and tilt inward from the top for safe ventilation. When closed, multi-lock mushroom-head pins engage around the perimeter, providing security performance comparable to casement windows. This is the most significant product innovation in the residential window market of the past decade.

Key Advantages for Building Projects

• Space-saving slide operation — no interior or exterior swing clearance required
• Multi-point locking with mushroom-head pins — security parity with casement
• Tilt position enables rain-safe ventilation without security risk
• Integrated screen mesh available for insect control
• Can accommodate PM2.5 filtration fresh air systems

EEHE Product Reference: Louvre Series — Integrated-Screen Drift Window

Key Engineering Details:

• Full injection-glue corner joints on frame, sash, mullion, and screen — no corner gap infiltration
• 360° continuous sponge foam composite gasket at glass perimeter — no cut-and-join gaps
• Slanted pressure bead design for enhanced visual layering
• Stepped drainage gutter uses gravity differential to prevent standing water
• Reinforced load-bearing ribs for large-span glass applications
• Custom fine-thread (dense-pitch) screws on hinge connections for maximum pull-out resistance

4. Fixed (Picture) Windows

Non-operable units designed solely for light transmission and views. Without moving parts or operating seals, fixed windows deliver the highest thermal and acoustic performance of any window type, with the lowest maintenance requirement. They are typically combined with operable casement or drift windows in a "picture window + vent" layout for residential and hospitality projects.

Structural Capabilities

• Maximum glass area: up to 11 m² per panel (NYK VOGUE casement series frame)
• Maximum glass area: up to 7.5 m² per panel (Louvre drift window series)
• Glass thickness graduated by area: 5 mm (≤2.5 m²) → 6 mm → 8 mm → 10 mm → 12 mm (>5 m²)

5. Specialty Window Systems

Awning (Top-Hung) Windows

Hinged at the top, opening outward. Operated by crank or push mechanism. Ideal for high or hard-to-reach placements, above doors, and in basement egress applications. The angled sash deflects rainwater away, enabling operation during light rain.

EEHE project reference: 200-unit Sydney luxury apartment project supplied with aluminium awning windows and sliding doors. Delivered noise reduction of 38 dB, U-value 1.8, and passed inspection on first attempt — 2 weeks faster than local supplier benchmarks.

Side-Pressure Windows

Side-pressure (lateral-press) windows use a lever mechanism to press the sash laterally against the frame, creating a compression seal similar to casement performance in a sliding format. They offer a middle ground between sliding convenience and casement-level sealing.

EEHE Product Reference: Paris Starry Sky Pro Series — Side-Pressure Window

Motorized Lift Windows

Electric motor-driven vertical lift windows are increasingly specified in contemporary minimalist architecture for large-format, automated openings. EEHE's Sky Mirror series addresses this segment, designed for modern residences and high-end apartment projects.

Curtain Wall Window Systems

For commercial and mixed-use projects requiring continuous facade glazing, EEHE offers the Milan Spring series thermal break curtain wall window (frame depth 175 mm, wall thickness 4.0 mm frame/2.2 mm sash, glass configuration 6 mm + 20Ar + 6 mm), bridging the gap between window and curtain wall specifications.

6. Window Type Comparison for Building Projects

Understanding the Five Performance Ratings

Note: All EEHE products are tested at Intertek and other accredited laboratories for all five performance categories. Test reports are available for individual product series upon request.

7. Glazing Specifications for Project Procurement

The glass specification is as critical as the frame and operating mechanism. For building professionals, the following parameters should be specified for each window type:

Insulated Glass Units (IGU)

• Standard double glazing: 5 mm + 20Ar + 5 mm (total package ~30 mm)
• High-performance upgrade: 5 mm + 24Ar + 5 mm to 5 mm + 25Ar + 5 mm
• Triple glazing available for extreme climate projects (6 mm + 14A + 6 mm + 14A + 6 mm)
• Glass thickness graduated by panel area: 5 mm (≤2.5 m²) → 6 mm → 8 mm → 10 mm → 12 mm (>5 m²)

Glass Coatings & Treatments

• Low-E coating: reflects infrared heat while transmitting visible light — winter heat retention and summer solar control
• Tinted/reflective coating: reduces solar heat gain coefficient (SHGC)
• Self-cleaning coating: photocatalytic reaction breaks down organic dirt
• Laminated glass: PVB interlayer for acoustic dampening and safety

Integrated Shading Solutions

Factory-integrated magnetic blinds (5 mm + 26Ar + 5 mm glass layout) and solar-powered electric blinds (6 mm + 21Ar + 8 mm) are available as sealed-within-IGU options, eliminating dust accumulation and maintenance access requirements — particularly valuable for hospitality and multi-residential projects where unit-level blind maintenance is logistically challenging.

Integrated Fresh Air Systems

Optional window-integrated PM2.5 filtration systems are available (horizontal model FD105, minimum 760 mm width, 110 mm installation clearance; vertical model SD120, minimum 1000 mm height, 125 mm installation clearance). These provide filtered fresh air without ductwork — a space-efficient solution for apartment projects targeting enhanced indoor air quality (IAQ) ratings.

8. Specification Guidance for Building Professionals

No single window type is universally optimal. The appropriate specification depends on the project's climate zone, building height, facade orientation, acoustic requirements, and energy code targets. The table below maps window type to project scenario:

Conclusion

For building professionals, selecting a window system requires evaluating measurable performance data — air infiltration rates, water penetration resistance, thermal transmittance (U-value), sound reduction index, and structural wind-load capacity — against project-specific requirements for climate, building height, budget, and design intent.

EEHE provides certified performance data for all product series, supported by Intertek test reports and international certifications including NFRC, CSA, and CE. Product specifications, project references, and technical documentation are available through the EEHE B2B portal or by contacting the engineering team directly.

For project inquiries, specification support, or sample requests:
Email: eehe029@eehewindows.com | eehe@eehehomes.com
WhatsApp: +86 18823156072
LinkedIn: EEHE Groups
Website: www.eehedoors.com

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