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?
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
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.