Soundproofing Your Home: A Practical Guide for Australian Homeowners

Understanding Airborne vs Impact Noise

Airborne noise (voices, music, TV) travels through air and then through building elements. Impact noise (footsteps on an upper floor, children jumping) is transmitted through structure. They require different solutions: airborne noise = sealing gaps and adding mass/insulation; impact noise = breaking the structural transmission path with floating floors, acoustic isolation mounts, etc.

The Most Cost-Effective Soundproofing Measures

• 1 Seal gaps first: a 1% gap in a wall allows 50% of sound to pass through. Seal gaps around doors, windows, and penetrations with acoustic sealant.
• 2 Door sweeps: a gap under a door is an enormous sound transmission path — fit a good quality automatic door drop seal
• 3 Heavy curtains with pelmets: significant reduction in external noise through windows, particularly traffic noise
• 4 Acoustic underlay under floating floors: reduces impact sound transmission to lower floors — specified by mass per m² rating

Upgrading Walls Between Dwellings

For party walls between townhouses or semi-detached homes, adding mass (acoustic plasterboard) with a resilient channel (decouples the new plasterboard from the wall frame) can reduce airborne sound transmission by 15-20dB — roughly halving the perceived loudness. Cost: $80–$150/m² of wall area. This is a significant but worthwhile investment for noisy shared walls.

Double Glazing for Traffic Noise

External traffic noise enters primarily through windows. Double glazing reduces noise by 20-35dB compared to single glazed windows — roughly a 3-4x reduction in perceived loudness. Acoustic laminated glass (a layer of acoustic PVB in the glass) outperforms air gap alone for noise reduction. Specify 6.38mm acoustic laminated glass as the inner pane for best results.