Recommended noise limits

In spatial planning, the authorities designate a noise zone around noise sources, where the noise level exceeds the recommended noise limit.

In spatial planning, the authorities designate a noise zone around noise sources, where the noise level exceeds the recommended noise limit. Below is a review of recommended noise limits for airports and airfields.

The recommended noise limits for airports and airfields are found in Guidelines from the Danish Environmental Protection Agency, no. 5/1994 "Noise from Airfields" (in Danish). They are used both for environmental permits and for spatial planning.

The recommended noise limits are expressed as DENL values (L _den ), which is the A-weighted average noise level over 24 hours including a 5 dB penalty for events during the evening period (19-22) and a 10 dB penalty for the night (22-07). In addition a 5 dB penalty applies to special aircraft activities (such as parachute flying, visual training flights, scenic pleasure flights, ultra light flying, etc.) in weekends and in the evening and night on weekdays.

In spatial planning, the authorities designate a noise zone around high-speed ferries and other noise sources, where the noise level exceeds the recommended noise limit. Below is a review of recommended noise limits for high-speed ferries.

Statutory Orders no. 821 of 23. October 1997 lays down rules for granting of environmental permits to high speed ferries.

The limit values for low frequency noise inside dwellings are:

The limit values apply to the A-weighted level of the noise in the frequency range 10–160 Hz, measured or calculated as the equivalent level over two minutes indoor, in the most exposed room.

In addition there are also limit values for the "normal" noise from high speed ferries, both for the average noise level (expressed as L _den ) and for the maximum A-weighted level, L _max . These have been found to be considerably less restrictive than the limits for the low frequency noise.

In spatial planning, the authorities designate a noise zone around industries and other noise sources, where the noise level exceeds the recommended noise limit. Below is a review of recommended noise limits for industries.

Noise from industry 

The recommended noise limits for industries, enterprises etc. are published in Guidelines from the Danish Environmental Protection Agency, no. 5/1984 "Environmental Noise from Industry" (in Danish).

The recommended noise limits are mainly used in processing environmental permits or bans related to noise. However, they are also used for spatial planning. The recommended limits differ in the day, evening and night periods.

The limit values apply to the corrected, A-weighted equivalent noise level (noise rating level L _r ).

The equivalent noise level is the average of the noise level over a long period of time, the reference time interval (eight hours for the day period 7am-6pm, one hour for the evening 6pm-10pm, and half an hour for the night period 10pm-7am). In case the noise has clearly audible tones or impulses, a 5 dB penalty is added to the equivalent noise level to obtain the noise rating level.

The limit values are to be kept out of doors in the adjacent area, not only in areas near dwellings or at the area's border. For dwelling areas a supplementary noise limit applies to the maximum (instantaneous) noise level during the night period. This is 15 dB above the corresponding L _r – limit for these periods, namely L _max = 50 or 55 dB.

Other limit values apply to the situation where the enterprise and the dwelling are in the same building. In such case the noise is to be measured indoors.

Since the recommended noise limits differ in the day, evening, and night periods, the drawing of a manageable noise zone around an industry is not straightforward. A set of recommended noise limits for purpose of general (and strategic) planning, each expressed as a single-figure Lden was published in Guidelines from the Danish Environmental Protection Agency, no. 4/2006 "Noise Mapping and Noise Action Plans" (in Danish).

In spatial planning, the authorities designate a noise zone around noise sources, where the noise level exceeds the recommended noise limit. Below is a review of recommended noise limits for low frequency noise, infrasound and vibrations.

The Danish Environmental Protection Agency has published recommendations about low frequency noise and infrasound in Information from the Danish Environmental Protection Agency, no. 9/1997 "Low Frequency Noise, Infrasound, and Vibrations in the Environment" (in Danish). Information is given about recommended limit values and recommended measurement methods are described.

The limit values for low frequency noise go for the A-weighted level of the noise in the frequency range 10–160 Hz, and the limit values for infrasound apply to the G-weighted infrasound level. Both measured indoors in the most exposed habitation room as an average over 10 minutes, following the specified measurement procedure. The measurement procedure was last adjusted in March 2010: Measurement procedure LFnoise (in Danish)

The recommended limit values for environmental vibration are:

• 75 dB in dwellings in dwelling areas (day, evening, and night), kindergartens, etc. plus dwellings in mixed areas in the evening and night period (6pm-7am)
• 80 dB in dwellings in mixed areas in the day period (7am-6pm) and in offices, rooms for teaching etc.
• 85 dB in enterprises other than offices.

These limit values apply to the maximum level of whole-body combined weighted acceleration, measured and analysed as specified.

Read more about low frequency noise from wind turbines

In spatial planning, the authorities designate a noise zone around motor sport tracks and other noise sources, where the noise level exceeds the recommended noise limit. Below is a review of recommended noise limits for motorsport tracks.

A special set of recommended noise limits for motor sport tracks is published in Guidelines from the Danish Environmental Protection Agency, no. 2/2005 "Noise from Motoring Tracks" (in Danish). They are used both for environmental permits and for spatial planning.

The noise limits differ as a function of the number of training days per week.

Day is from 9am-6pm on weekdays and 9am-2pm on Saturdays.
Evening is from 6pm-8pm on weekdays and 2pm-6pm on Saturdays.

The limit values apply to the A-weighted equivalent level over one hour. Usually there are no noise limits for public races and similar events in the environmental permit, but a restricted number of events per year.

In spatial planning, the authorities designate a noise zone around noise sources, where the noise level exceeds the recommended noise limit. Below is a review of recommended noise limits for railways.

The recommended noise limits for railway noise are published in an addendum from July 2007 to Guidelines from the Danish Environmental Protection Agency, no. 1/1997 "Noise and Vibration from Railways" (in Danish) Additional guidelines, no. 1/1997 "Noise and Vibration from Railways" (in Danish). Like the recommended noise limits for roads, they are mainly used in spatial planning and expressed in terms of Lden. 

The noise limits for railway noise are:

• Recreational areas in the open country (areas for holiday cottages, camping sites, green areas, etc.): 59 dB
• Recreational areas near or in cities (parks, allotment gardens, city camping, etc.): 64 dB
• Dwelling areas (dwellings, areas for staying out of doors): 64 dB
• Public purposes (hospitals, institutions, schools, universities, etc.): 64 dB
• Commercial purposes (hotels, offices, etc.): 69 dB

There are also requirements for both the maximum noise level and vibration level of the individual dwellings. The recommended limit for the maximum level is 85 dB, and limit vibrations is 75 dB KB-weighted acceleration level.

To avoid vibrations a planning-related minimum distance is provide between track center and the mentioned areas (except for allotment gardens). If documented that the vibration can be observed there may be built closer to the track.

In spatial planning, the authorities designate a noise zone around roads and other noise sources, where the noise level exceeds the recommended noise limit. Below is a review of recommended noise limits for road traffic.

The recommended noise limits for road traffic noise are described in Guidelines from the Danish Environmental Protection Agency, no. 4/2007 "Noise from Roads" (in Danish).

The recommended noise limits are mainly used in spatial planning when planning for dwelling areas near existing roads. Moreover, they are used for assessment of noise impact in existing dwellings as well. It is recommended to consider the noise impact and secure the lowest possible noise level when planning new roads and road expansions.

Before 2007, the noise limits were expressed as 24-hour L _Aeq , but since 2007 they are expressed in terms of Lden. Here a 5 dB penalty is applied to noise events in the evening period (7pm–10pm) and 10 dB in the night period (10pm–7am).

The noise limits for road traffic noise are:

• Recreational areas in the open country (areas for holiday cottages, camping sites, green areas, etc.): 53 dB
• Recreational areas near or in cities (parks, allotment gardens, city camping, etc.): 58 dB
• Dwelling areas (dwellings, areas for staying out of doors): 58 dB
• Public purposes (hospitals, institutions, schools, universities, etc.): 58 dB
• Commercial purposes (hotels, offices, etc.): 63 dB

Read more about traffic noise

In spatial planning, the authorities designate a noise zone around shooting ranges and other noise sources, where the noise level exceeds the recommended noise limit. Below is a review of recommended noise limits for shooting ranges.

For shooting ranges the recommended noise limits appear in Guidelines from the Danish Environmental Protection Agency, no. 1/1995 "Noise from Shooting Ranges" (in Danish). They are used both for environmental permits and for spatial planning.

The recommended noise limits for newly planned and existing shooting ranges differ. The limit applies to the maximum A-weighted level from a single shot, using time weighting "I" (Impulse), and measured or calculated at the most exposed dwelling. The limit value is a function of the number of practicing days per week and the duration of the shooting period. Longer shooting periods result in lower noise limits.

For new shooting ranges the noise limit is from 70 dB, for a shooting range used only one day and evening per week, till 60 dB, if the range is used every evening. In cases with shooting later than 22 in the night the noise limit can be as low as 55 dB.

The recommended noise limits for existing shooting ranges are higher, up to 80 dB. It is left to the authorities to decide on the amount of noise reduction needed on an existing range, whereas the assessment starts from the recommended limits for new shooting ranges.

In spatial planning, the authorities designate a noise zone around wind turbines and other noise sources, where the noise level exceeds the noise limit. Below is a review of noise limits for wind turbines.

Noise limits for wind turbines

Statutory Orders no. 1518 of 14 December 2006 sets mandatory noise limits for wind turbines.

• 44 dB in areas for staying out of doors in direct connection to (up to 15 m from) dwellings in the open country, and
• 39 dB in dwelling areas and similar noise sensitive use.

The noise limits apply to the calculated noise level from all wind turbines in the area at 8 m/s wind speed. In addition, the statutory order has noise limits at 6 m/s, these are 2 dB lower. The statutory order includes the calculation method to be used and specifies the method for measuring noise emission from wind turbines.

Revising the Statutory Order on wind turbines

The Environmental Protection Agency has revised the Statutory Order on Wind Turbines to include mandatory limit values for low frequency noise. The new limit values will apply to turbines for which applications are made after the Statutory Order enters into force, which is expected to be at the end of 2011.

Read more about noise from wind turbines