Soundproofing Your Home: Can Aluminium Glazing Keep Out Street Noise?

Portugal's vibrant cities offer rich cultural experiences, but urban living often comes with unwanted noise. From Lisbon's iconic tram lines to Porto's bustling downtown traffic, street noise can significantly impact quality of life. Many residents, particularly those relocating to city centres or tourist areas, find themselves struggling with traffic noise, construction sounds, and late-night activity. Modern aluminium glazing systems offer effective solutions, capable of reducing street noise by 40-60% when properly specified and installed.

Understanding Sound Transmission: STC Rating Explained

Sound transmission through windows is measured using the Sound Transmission Class (STC) rating system. This standardised measurement indicates how many decibels of sound a window system can block across different frequencies.

STC rating interpretation:

• STC 25-30: Standard single glazing - minimal noise reduction

• STC 30-35: Basic double glazing - moderate noise reduction

• STC 35-40: Quality double glazing with acoustic features - good noise reduction

• STC 40-45: Specialist acoustic glazing - excellent noise reduction

• STC 45+: Premium acoustic systems - exceptional noise reduction

Frequency considerations are crucial because different types of noise occur at different frequencies. Traffic noise typically ranges from 125Hz to 4000Hz, with peak energy around 500-1000Hz. Human voices centre around 1000-2000Hz, while construction equipment can generate noise across the entire spectrum.

Real-world application: An STC 40 window can reduce a busy street's 70-decibel traffic noise to a comfortable 30-decibel interior level—equivalent to a quiet library setting.

Double vs Triple Glazing for Acoustics

The choice between double and triple glazing significantly impacts acoustic performance:

Double glazing acoustic benefits:

• Asymmetric glass thickness (e.g., 6mm + 8mm) reduces sound transmission better than symmetric configurations

• Wider air gaps (16-20mm) provide better acoustic insulation than narrow gaps

• Cavity treatment with acoustic foam or specialised gas fills enhances performance

• Cost-effectiveness makes double glazing suitable for most urban noise situations

Triple glazing advantages:

• Multiple barriers create additional sound attenuation

• Resonance disruption occurs at different frequencies in each cavity

• Superior performance for extreme noise environments

• Thermal benefits complement acoustic improvements

Optimal configurations:

• Double glazing: 8mm laminated glass + 18mm cavity + 6mm standard glass achieves STC 38-42

• Triple glazing: 6mm + 12mm cavity + 8mm laminated + 14mm cavity + 6mm achieves STC 42-46

Aluminium Frame Features That Boost Noise Insulation

Modern aluminium frames incorporate several acoustic enhancement features:

Thermal breaks not only improve thermal performance but also reduce sound transmission through the frame structure. The polyamide thermal break material has different acoustic properties than aluminium, creating a sound barrier within the frame itself.

Multi-chambered profiles create additional air spaces that disrupt sound waves. Advanced aluminium systems feature up to 5 separate chambers within the frame profile, each contributing to overall acoustic performance.

Precision manufacturing ensures consistent gaps and tolerances, preventing sound leakage through poorly fitted components. Computer-controlled manufacturing processes achieve tolerances of ±0.1mm, critical for acoustic performance.

Integrated gasket systems provide multiple sealing points. Quality aluminium frames feature primary weatherstripping for air and water resistance, plus secondary acoustic seals specifically designed for sound attenuation.

Tips: Seals, Laminated Glass, and Specialist Glazings

Acoustic sealing strategies:

• EPDM gaskets provide superior acoustic performance compared to standard rubber seals

• Compression seals create consistent pressure across the entire frame perimeter

• Corner welding eliminates gaps at frame joints where sound typically leaks

• Adjustable hardware maintains seal compression over time

Laminated glass benefits:

• PVB interlayer acts as a sound-dampening membrane between glass layers

• Acoustic PVB specifically designed for sound control offers 2-3 decibel additional reduction

• Thicker laminates (1.5mm PVB vs 0.76mm standard) provide enhanced acoustic performance

• Asymmetric lamination combining different glass thicknesses maximises sound reduction

Specialist glazing options:

• Acoustic glass units with different glass thicknesses and cavity widths

• Vacuum glazing eliminates air-borne sound transmission through the cavity

• Resin-bonded glass systems for extreme acoustic requirements

• Dynamic glass with variable acoustic properties for different noise conditions

Budget considerations:

• Standard upgrade: Replacing single glazing with basic double glazing provides immediate 40-50% noise reduction

• Mid-range solution: Acoustic double glazing offers excellent value for most urban situations

• Premium investment: Triple glazing or specialist acoustic systems for challenging environments

Installation Checklist: Site Preparation for Maximum Attenuation

Pre-installation assessment:

• Noise source identification: Determine primary noise sources and frequencies

• Structural evaluation: Assess wall construction and integration requirements

• Ventilation planning: Ensure adequate air circulation without compromising acoustic performance

• Existing conditions: Document current noise levels for before/after comparison

Installation critical points:

• Perimeter sealing: Apply acoustic sealant around the entire frame perimeter

• Cavity insulation: Fill wall cavities with acoustic insulation materials

• Mechanical fixing: Use appropriate fixings to prevent vibration transmission

• Testing verification: Verify acoustic performance meets specified requirements

Quality control measures:

• Seal continuity: Inspect all sealing points for gaps or defects

• Hardware adjustment: Properly adjust all moving parts for optimal seal compression

• Drainage provision: Ensure water drainage without compromising acoustic seals

• Documentation: Record installation details for future maintenance

Frequently Asked Questions

Can upgrading glazing reduce street noise by 50%? Yes, quality double glazing with acoustic features typically reduces street noise by 50-60%. The exact reduction depends on the existing window type, noise frequency, and specific glazing specification. A professional acoustic assessment can predict expected noise reduction for your specific situation.

Will laminated glass make my home noticeably quieter? Laminated glass provides significant acoustic benefits, typically reducing noise by an additional 2-4 decibels compared to standard glass. This translates to a noticeable reduction in perceived loudness, particularly for high-frequency sounds like voices and electronic noise.

How long does acoustic glazing installation take? Most residential installations complete within 1-2 days, depending on the number of windows and complexity. The process involves removing existing windows, preparing openings, installing new frames, and conducting final adjustments. Minimal disruption to daily routines.

Do I need planning permission for acoustic glazing? In most cases, upgrading existing windows doesn't require planning permission. However, properties in historic areas or with specific architectural requirements may need approval. AltaGlaze can advise on local regulations and assist with any necessary applications.

Can I achieve good acoustic performance with just frame upgrades? While frame improvements help, the glazing specification has the greatest impact on acoustic performance. Combining quality frames with acoustic glass provides optimal results. Frame-only upgrades typically achieve 20-30% noise reduction compared to 50-70% with complete glazing system upgrades.

Modern aluminium glazing systems offer effective solutions for Portugal's urban noise challenges. Through careful specification of acoustic glass, thermally broken frames, and professional installation, street noise can be reduced to comfortable levels while maintaining the aesthetic and functional benefits of aluminium glazing. For expert acoustic assessment and installation of noise-reducing glazing systems, contact AltaGlaze's experienced team to transform your home's acoustic environment.