Construction noise: Know the limits
Many construction and demolition activities are inherently noisy. However, noise generated during construction, maintenance and demolition work is generally of a temporary nature. Provided ongoing noise does not occur at inconvenient times, the adverse effects can generally be avoided or mitigated.
NZS 6803:1999 Acoustics – Construction noise allows for the production of significant noise between the hours of 7.30am to 6pm during weekdays. The standard also contains provisions relating to:
- the measurement of noise from construction, maintenance and demolition work
- the assessment of such noise to determine whether action is required to control those noise emissions.
- In the event of non-compliance, action can be taken under the appropriate sections of the Resource Management Act.
NZS 6803:1999 sets out recommended upper limits in dB(A) for construction work noise in residential areas:
L10 is the noise level exceeded for 10% of the time of the measurement period. For example, a noise limit of L10 75 dB(A) means that, over a period of 1 hour, the noise from construction activities can only exceed 75 dB(A) for a total of 6 minutes or 1 minute over a period of 10 minutes.
L95 is the level exceeded for 95% of the time and represents the background level without any construction noise present.
Lmax is the maximum level measured over a time period, but it is not the same or not as high as an individual peak level
To help reduce building noise, consider:
- limiting work hours
- selecting quieter equipment or use alternatives
- carrying out work as far away as possible from neighbours and away from sensitive areas such as bedroom windows
- regularly servicing equipment – lack of maintenance can cause higher noise levels
- erecting a solid fence or barrier
- installing an acoustic enclosure for fixed equipment such as compressors or vacuum equipment
- modifying equipment – discuss this option with the manufacturer or installer.
If noisy work is planned, such as jack hammering, concrete cutting and pouring, discuss this with nearby residents beforehand. A sign on site or distribution of leaflets explaining the hours and duration of operation may help prevent complaints.
Reprinted with permission from BRANZ