What do you need to consider?
Boverket's building regulations, BBR, contains regulations and general advice on the noise protection of buildings. The rules clarify the basic requirements for noise protection contained in the Planning and Building Act, PBL, and the Planning and Construction Regulation, PBF.
According to PBL, construction works must have the technical characteristics essential for protection against noise. PBF states that buildings must be designed and built so that noise does not pose unacceptable health risks. It should be possible to sleep, rest and work in satisfactory conditions.
Rules and recommendations regarding the sound environment in public spaces are also given by the Swedish Work Environment Authority, the Public Health Agency of Sweden, and the Swedish Environmental Protection Agency.
Two separate standards for sound rating
There are two Swedish standards for building acoustics and sound classification of spaces in buildings. Standard SS 25268 deals with public spaces such as care rooms, teaching facilities, daycare and leisure facilities, offices, and hotels. The standard SS 25267 is for housing.
Sound classes are divided into A, B, C or D class where A is the highest sound reduction. Class C corresponds to the minimum requirements laid down in BBR for newly built dwellings or premises. With each step up or down, the rating requirements change by about +/– 5 dB.
The requirements for sound reduction vary
Door sound reduction is indicated by the weighted sound reduction index Rw. The Rw value is measured in the unit dB (decibels) and is a measure of how effectively walls, floors, ceilings – and doors – prevent the sound from passing on. Rw is measured and tested in a laboratory environment unlike R'w which is a value measured with the door mounted in the environment, which during design should be reduced by 2-3 dB compared to the Rw value.
The activities in the premises determine the requirements for sound reduction. A few simple guidelines indicate the levels.
Rw 48-53 dB
Offers call privacy. Screams and loud activity can be heard faintly at the lower end of the range. A soundproofing level that offers acceptable conditions in environments where privacy requirements are not complete, but privacy requirements are clear.
Rw 39-47 dB
Offers some call confidentiality. Single words in loud conversations can be heard but not really understood. A sound insulation level that may be considered as relatively high standard in, for example, offices where workspaces are to be separated from conference rooms.
Rw 34-38 dB
Audible calls can be perceived but at the same time difficult to discern in detail. A sound insulation level which can be considered as the lowest standard, where there is a requirement for sound insulation and privacy.
Normal calls can be heard in the lower isolation levels. In the upper layer, single words can be heard at normal call height but can be difficult to perceive. A low insulation standard that can be accepted in cases where low requirements are placed on sound insulation.