Noise Control on Construction Sites

We’ve all heard about noise control requirements related to loud parties but do you know your responsibilities as a builder on noise control for a construction site? 

Under the Resource Management Act your local Building Consent Authority administers noise control standards to ensure that construction noise remains at a reasonable level and occurs at a reasonable time. It covers all construction operations including demolition, site preparation and earthmoving and the use of any plant or tools.

Noise levels are measured in decibels [dB] but because our hearing is less sensitive to lower frequencies and the level differs depending on the distance from the noise source, noise level ratings are adjusted through a formula and become ‘A-weighted data’. In older documents this is shown as dBA.

NZ Standard 6803 Transport Noise provides comprehensive details of noise control calculation methods and sets guideline noise limits for construction and maintenance works. For full details with worked examples look at the NZ Transport Agency website here. Look for New Zealand Standard 6803, for details on construction, allowable sound levels and calculation methods.  BCAs can use this standard or set their own and they often set lower limits.

Recommended upper limits of construction work noise is often different between:

•    Residential and industrial/commercial areas
•    Noise sensitive areas such as schools
•    Weekdays as opposed to Saturday, which is different again for Sundays and public holidays
•    Time of day, with common time groups being 0630 – 0730, 0730 – 1800, 1800 – 2000, 2000 – 0630

Duration of noise level is another contributing factor and requirements can be different depending on the duration of works at location. Similarly, a variety of upper limits can be set including the:

•    Maximum noise level
•    Average noise level
•    Noise level that can only be exceeded for say 10% of the time
•    Noise level that can only be exceeded for say  95% of the time  

Wondering what type of noise levels occurs on your site and how it compares with activities from normal life?

140 dB    pneumatic rock breaker    ~           80 dB     busy street
130 dB    threshold of pain                  ~           75 dB    loud radio
120 dB    compactor                             ~           60 dB    conversation
105 dB   10-tonne dump truck           ~           40 dB    library
90 dB    power drill                               ~          30 dB    whisper                   

 

At first glance it seems very complicated but check out your local BCA and see what rules apply to building operations in your area. Individual resource consents may have extra noise restrictions or there may be restrictions on hours of site operation. It is generally accepted practice that noisy construction work is not permitted on a Sunday or public holiday. 

But there is hope that common sense will prevail if a complaint is registered. Then a noise control officer will be called out to investigate and determine if the noise is reasonable and whether construction work is occurring at permitted times. It may not be necessary to use monitoring equipment to determine if the nose is excessive. 

A variety of outcomes may occur including no change although it would be an unwise builder who would not take note of such a complaint made as good public relations is all part of a smart marketing package.

Being served a warning or a written direction to reduce noise, which can remain in force for several days, means a more serious approach to the matter needs to be considered. Particularly when failure top obey the notice can result in equipment seizure or a hefty fine. And remember, if the noise is being created by one of your sub-contractors you have a liability as head contractor to see that the problem is resolved and it will again be your reputation that suffers.

Note that you can get special permission to complete work outside these times or levels for emergencies or because of public safety or traffic hazards. As a public relations exercise it is recommended that you advise residents who may be affected by such noise about the days and times of such operations with contact numbers so they ring you first.

A quick check list of what to think about if loud noise or having to work extended hours becomes a major issue includes