NEIGHBOR NOISE HAS ALWAYS BEEN CONSIDERED a significant factor in the rating of satisfaction in new and refurbished dwellings. The control of sound within dwellings is therefore a statutory requirement in most countries and it is also included in most assessment methods used to determine sustainability. In most instances the statutory requirements are set as minimum target values rather than optimum insulation levels and as a result there can be conflict between end-user expectation and national or regional requirements. The target values adopted around the world look to provide reasonable levels of insulation in the hope that this will satisfy the majority of occupants. For this reason, designers and developers should be wary of using terms like “soundproof,” as even the best-performing walls and floor systems have the potential to allow for some transmission of sound.
12.2.1 Partitions between dwellings
Table 12.1 details the level of occupant satisfaction compared to the measureable sound insulation for partitions separating dwellings. Appendix C outlines a limited number of partition types for use in separating constructions.
Controlling sound transmission is most important in adjoined dwellings and it is generally a requirement of building codes and regulations in many countries across the globe. Table 12.2 shows the expected performance levels required by different building regulations in some countries around the world.
Table 12.1 Perceived satisfaction levels of sound insulation for separating partitions (Smith et al., 2006)
Perceived rating | Airborne sound | Impact sound |
DnT,w (dB) | L’nT,w (dB) | |
A*Excellent | 62–64 | <47–49 |
A Very good | 59–61 | 50–52 |
B Quite good | 56–58 | 53–55 |
C Acceptable | 53–55 | 56–58 |
D Barely acceptable | 50–52 | 59–61 |
E Poor | 47–49 | 62–64 |
F Very poor | 44–46 | 65–67 |
G Intolerable | 41–43 | 68–70> |
12.2.2 Internal partitions
In addition to sound insulation between dwellings, it is considered good practice to ensure a minimum level of acoustic insulation for partitions within dwellings. Insulation levels of STC/Rw 40–43 dB should be seen as a minimum requirement for walls and floors within a house.
The use of single stud partitions with high-mass plasterboard linings (e.g., minimum 10 kg/m2) and the inclusion of a layer of mineral fiber quilt would provide a minimum specification to achieve this level.
12.2.3 Doors to apartments/flats
Doors to apartments/flats which open onto a common lobby or stairwell should be specified as having a minimum performance of STC/Rw 29 dB. Solid core timber doors are usually capable of achieving this level of insulation. It is also good practice to include compressible seals in these doors in order to reduce sound transmission.
THE FOLLOWING ADVICE OUTLINED in Figures 12.1 and 12.2 would hold true for any building design, but it is particularly relevant to the design of housing or rooms for residential purpose where the aim is to reduce the magnitude of noise being transmitted from one part of a building to another.
Table 12.2 Domestic sound insulation requirements around the world for new-build constructions (COST, 2013)
1 As per proposed changes 2013
*United States guidelines for federal housing; state guidelines may differ
+ First value is for laboratory test data; value shown in brackets for on-site testing
Steps and staggers between noise-sensitive buildings can help improve sound insulation by reducing the effective area of common wall.
Minimum steps and staggers of 1 ft (30 cm) should be considered if included for acoustic performance reasons.
Steps and staggers of this size or greater can improve performance by up to 6 dB.
Stack rooms so that noise-sensitive spaces are above one another. Avoid placing kitchens above or below bedrooms.
Cluster around a central stair well so that areas of common walls are limited in size.
12.2 Avoiding sensitive adjacencies in multistory buildings
12.3 Handling of adjacent rooms
Design layouts so that noisy activities back on to less sensitive areas (e.g., kitchens to circulation).
Situate noise-sensitive spaces such as bedrooms as far from other dwellings as possible.
Place stairwells and lift shafts as remote from noise-sensitive areas as possible.
Noise from common circulation spaces can be further reduced by separating the stairwell from the entrance lobby to the dwellings on each floor with a glazed screen and door.
Advice specific to individual building types is given in other sections of Part II of the book, but for general layouts within dwellings Figure 12.3 offers some basic guidance.
Use stairwells, circulation, and cupboard space as buffer zones between noise-sensitive rooms such as lounges and bedrooms. Limiting direct adjacencies of noise-sensitive spaces is preferred.
Where adjacencies are unavoidable, place quiet rooms back-to-back and noisy rooms back-to-back (e.g., kitchen to kitchens, and lounges to lounges).