Example 7, Gothenburg noise policy and quiet façades
The noise policy of Gothenburg was decided in 2006. Quiet façades and courtyards are an important part of the policy, at least regarding new dwellings in central areas. The policy only applies within 4 km of the city centre and close to public transport.
Our noise policy aims at new dwellings in areas with high noise levels and when and how the national guideline limits (55 dBA (LAEq,24h), 70 dBA (LAFmax)) can be surpassed. The basic idea of the policy is that high noise levels on one side can be compensated with lower noise levels on the other side and in courtyards and on balconies or patios.
What does the policy say?
If noise levels at the exposed façade are somewhere between 55 dBA (LAEq,24h) and 65 dBA (LAEq,24h) this could be compensated with a quiet façade where the levels should preferably be below 45 dBA (which we call a quiet façade) and must be below 50 dBA (called a "silenced" side). This is illustrated in figure 1 below. Courtyards are usually regarded as part of the quiet side where 45 or at least 50 dB (LAEq,24h) is the level to achieve.
The demands regarding indoor noise levels are higher if traffic noise levels are above 60 dBA (LAEq,24h). Then 26 dBA (LAEq,24h) and 41 dBA (LAFmax) should be reached, as opposed to 30 and 45 when below 60. If traffic noise levels are above 65 dBA (LAEq,24h) no dwellings should be built, but other buildings such as offices may be built (for example as a barrier).
A new policy on the way!
Quiet areas, such as parks, are not yet a part of the city's formal policy. However, the city is working on creating a new noise policy which should address noise from a wider perspective and take what we call the "sound environment" of the area into account. This means that, for example, parks and kindergardens should also be part of the assessment. The top level of 65 dBA will probably be abolished, in central parts of the city, in accordance with the new Swedish national regulations.