Building to reduce noise

Throughout the Central Coast and Hunter regions there are plenty of noisy area’s near roads, rail and industry. If urban density rates continue to increase then more and more people will need to talk to their builder about how to mitigate the local noise for a peaceful living experience in your home.  

So how noisy are things?

Environmental Noise

Weakest sound heard 0 dB

Normal breathing 10 dB

Quiet room 20 dB

Whisper Quiet Library 30 dB

Quiet office / refrigerator 50 dB

Normal conversation ` 60-65 dB

Telephone dial tone / Vacuum 80 dB

City Traffic (inside car) 85 dB

Level at which sustained exposure may result in hearing loss 90 – 95dB

Truck Traffic 90 dB

Jackhammer 20mtrs 95 dB

Train at 60mtrs 95 dB

Power mower at 1mtr 107 dB

Motorcycle 100 dB

Power saw / leaf blower at 1 mtr 110 dB

Loud Rock Concert 115 dB

Pain begins 125 dB

Pneumatic riveter at 1mtr 125 dB

Jet engine at 30mtrs 140 dB

12 Gauge Shotgun Blast 165 dB

Death of hearing tissue 180 dB

Loudest sound possible 194 dB

Target noise

According to the WHO your bedroom should be ok up to around 30 dB continous. For brief periods up to 40 dB are ok. 

Mitigation of noise

So if you know what noise is at your home and what level you want to get it down to eg 40dB, then we can now look at designing the home to lower your internal noise levels to an acceptable level 


It is not just double glazing. There is the frame and seal to consider also. Our supplier Bradnams has single and double glazed options. 

Glazing can achieve ratings up to Rw44. Rw is the weighted sound reduction Index in dB. 


BCA Rw requirements for walls between adjoining dwellings

Structure Minimum reduction index (Rw)

Floors above dwellings 50

Walls between a bathroom, laundry or kitchen 

and a habitable room in adjoining dwelling* 50

Other walls 45

*These walls must also have a satisfactory level of impact insulation as outlined in the code

Source: ABCB 2011

So walls need to lower noise between dwellings also. 


This is absolutely critical to noise management as it applies to the walls and importantly the ceiling also. 


Distance is the easy win. For every doubling of distance, sound reduces by 6db.

With the calculator if you know a train is at 85dB at 10mtrs and your home is 100 mtrs away, the noise at your window will be 65dB. You will then need to take measures to lower the internal noise by at least 25dB. 

Further reading