Technical Guide to Windows for New Construction Homes

Introduction to New Construction Windows

Selecting the correct window system in new

impacts structural integration, thermal insulation, airtightness, ventilation, and façade continuity. This technical review explores energy-efficient window options, including European tilt and turn windows, Low-E glazing, argon gas insulation, and frame material comparisons across uPVC, wood, and aluminum.

Functional Requirements of Windows in New Construction

Modern window systems must satisfy:

• Structural load-bearing and wind resistance

• Airtightness per ASTM E283 or EN 1026

• Water tightness (ASTM E547 / EN 1027)

• Thermal performance (U-value and SHGC)

• Acoustic insulation (Rw rating)

• Compatibility with vapor barriers and wall assemblies

• Security standards (e.g., PAS 24 or RC2)

Window Types for New Construction

Fixed Glazing Units

Non-operable units that prioritize insulation and daylighting. They eliminate operable hardware, reducing infiltration points. Ideal for passive designs or high-performance walls.

Casement and Awning

Hinged along one edge. Provide full perimeter compression sealing. Better thermal performance than sliding windows due to improved airtightness.

Double-Hung and Single-Hung

Sash-based movement vertically. Lower sealing pressure results in higher air leakage. Suitable where traditional style is prioritized over performance.

Sliding Windows

Horizontal movement. Limited sealing surface area. Suitable for moderate climates or cost-sensitive applications.

Tilt and Turn (European Style)

Dual-functionality:

• Tilt mode (approx. 10–15° tilt) for secure ventilation

• Turn mode for full in-swing operability (easy cleaning, egress)

Advantages:

• Multipoint locking enhances perimeter seal compression

• Superior thermal bridging control with continuous gasket profiles

• Rigid steel reinforcement in sash/frame to prevent warping

• Ideal for integrating into airtight wall assemblies

Glazing Technologies

Low-E Coatings

Microscopic metal oxide layers reflect infrared radiation, minimizing solar gain or heat loss. Variants:

• Hard coat (pyrolytic): durable, high solar gain

• Soft coat (sputtered): better U-value, lower emissivity, requires IGU assembly

Argon/Krypton Gas Fill

Inert gases between glazing panes reduce convective heat transfer. Typical cavity width:

• Argon: 12–20mm for optimal performance

• Krypton: smaller cavities, higher cost, used in triple-glazing

Spacer Systems

• Aluminum spacers (traditional, higher conductivity)

• Warm-edge spacers (composite, reduced thermal bridging)

• Structural foam spacers with desiccants (premium thermal isolation)

Double vs. Triple Glazing

• Double glazing U-value: ~1.2–1.6 W/m²K (with Low-E + argon)

• Triple glazing U-value: ~0.7–1.0 W/m²K

Triple glazing improves condensation resistance, sound reduction (STC +3–5 over double), and passive house compliance.

Frame Materials

uPVC (Unplasticized Polyvinyl Chloride)

• Chambers within profile for insulation and drainage

• Steel or fiberglass reinforcement required in large spans

• Compatible with welded corner joints

• Low thermal conductivity (~0.17 W/mK)

• UV stabilizers required for color retention

Wood Frames

• Superior natural insulation (~0.13 W/mK)

• Laminated profiles (LVL, finger-jointed pine) resist warping

• Requires surface treatment (e.g., micro-porous paint)

• Suited for heritage or low-carbon construction

European tilt and turn windows in timber deliver excellent acoustics and thermal ratings, particularly in softwood-aluminum hybrid designs.

Aluminum Frames

• High strength-to-weight ratio

• Requires thermal breaks to prevent bridging (polyamide strips 14–34mm)

• Ideal for large format glazing, commercial buildings

• Surface finish: anodizing or powder coating

Thermally broken aluminum tilt and turn systems meet Passivhaus standards when combined with triple glazing.

Wood-Aluminum Hybrids

• Timber frame with external aluminum cladding

• Zero maintenance exterior, warm interior

• Higher cost but long service life

• Typical U-value: 0.8–1.2 W/m²K (with triple glazing)

Installation Considerations

• Windows must be fastened through the frame (not through sashes) using non-corrosive anchors

• Set in pan flashings with slope-to-drain geometry

• Airtight membrane connections from frame to WRB (weather-resistant barrier)

• Insulation continuity around frame perimeter critical to eliminate thermal bridging

Summary Performance Benchmarks

Feature	Double-Hung	Casement	Tilt & Turn
U-Value (avg, W/m²K)	1.6–2.0	1.2–1.6	0.8–1.3
Air Leakage (cfm/ft²)	0.3–0.5	0.1–0.2	<0.1
Sound Insulation (Rw dB)	28–32	30–36	34–42
Egress / Cleaning Access	Limited	Moderate	Excellent