Planning and noise guidance
Any industrial or commercial development must not cause an increase in background noise levels at the nearest noise sensitive property, or at the boundary of the property. The guidance generally recommends that noise levels within residential properties should not exceed the World Health Organisation values where practicable.
Noise measurement and calculation
BS 4142, BS 8223 and the World Health Guidelines all give values and design ranges for the measurement of noise in certain situations. It is unlikely that anyone other than a qualified noise consultant will be able to carry out an assessment of the noise. A representative assessment will be required to include special circumstances, for example, tonal values, impact noise, number and loudness of individual events, weather conditions and so on.
The assessment needs to cover the noisiest periods, taking into account the character of the area, for example, shift patterns in businesses. The assessment also needs to include the night time noise levels.
Certain information must be recorded including isolated events which would not be represented in an equivalent noise level [LAeq] taken over a longer period, for example, a train which passed at 5:00am, or unpredictable impact noise. High incident noise levels for short periods may cause sleep disturbance.
Daytime LAeq [7:00am to 11:00pm] at representative points around the site or at various facades
Night time LAeq [11:00pm to 7:00am] at representative points around the site or at various facades
LAmax values for the daytime and night time period.
Individual noise events should not exceed 45dB LAMAX (BS 8233. 1999)
night time (23:00 to 07:00)
day time (07:00 to 23:00)
Gardens and terraces
day time* (07:00 to 23:00)
*not in town centre or near main roads
The simplest method of assessing the insulation requirement of a façade is to subtract the internal noise level from the free field external level. For example, measured level 65 dBLAeq Glazing reduction of 35 RTRA Internal level 30 dBLAeq (according to BS 8233: 1999 simple method).
Glazing in residential property
In some cases standard thermal double glazing units be sufficient, other cases will need a thicker unit with specialist glass. If low frequency noise is an issue secondary units in conjunction with single or double glazed units may be required.
Both trickle and rapid ventilation will need to be considered, this may vary from standard trickle vents to fully mechanical powered ventilation. The ventilation must not compromise the effect provided by the glazing
Flues/chimneys serving domestic heating appliances give rise to emissions of smoke.
A significant proportion of Northampton Town is in a smoke control area (SCA). If you want to find out if you live in an SCA you can use our mapping system.
Where a smoke problem from a chimney/flue occurs on a regular basis and is persistent we can investigate under statutory nuisance provisions. Complaints are more likely to be received when:
- the flue/chimney is installed in an inappropriate location
- there is a material defect in the installation
- an inappropriate fuel is being burnt which it was not designed for
- the heating appliance is not being used/serviced, maintained in accordance with the manufacturer’s instructions or sufficiently cleaned; and/or
- the flue/chimney is not maintained or sufficiently cleaned
On occasions smoke may not disperse directly upwards from a flue/chimney. This can be for several reasons:
- initial light up of a fire - Solid fuel heating appliances need time to achieve an optimal operating temperature. This temperature promotes effective dispersal of the combustion products
- downdraughts - Smoke plumes can disperse directly downwards from the exhaust point as a result of pressure variations between the inside and outside of the building. Downdraughts can also be caused where the airflow around a chimney is impeded due to the presence of taller trees/buildings nearby
- certain weather conditions such as a temperature inversion can also impede the upward dispersal of a smoke plume. These conditions typically occur on cold sunny/foggy mornings/days in the winter and spring for example
Therefore, careful consideration should be given to the positioning and height of any flue/chimney serving a heating appliance. Regard should be given to the prevailing wind conditions for that location and proximity and height of neighbouring properties relative to the exhaust point of the flue serving the heating appliance.
To avoid the possibility of a statutory nuisance occurring it is recommended that any flue/chimney serving a solid fuel heating appliance should extend above the roof ridge height of the building to which it is attached, and the exhaust height be positioned more than 20 metres from the openings on neighbouring properties.
The heating appliance and flue should also be installed, operated, and maintained in accordance with the manufacturer’s instructions.
Developers and applicants must provide information on the following matters relevant to each of the planning class order:
|Class order||Information required|
|A1 and A2||Noise|
opening hours (including deliveries and servicing)
fume and externally mounted plant
Refuse storage and removal
|A3, C1, C2, D1 and D2||
Noise from the premises and patrons
|B1||Noise from the building and process (including impact and vehicle noise)|
externally mounted plant
Fumes, vapours and odours
Hours of work including deliveries and servicing
|B2||As B1 assessment is likely to be more rigorous and may involve the Environment Agency and/or the Local Authority, determination will be required as to IPPC|
|C3||Noise assessment required in most cases|
Possibly fume, odour, waste storage
Any premises with a combustion appliance rated higher than 0.4 MW heat input is likely to require prior approval of chimney height under the Chimney Height Approval Regulations.