Skip to Main Content

The UK’s leading supplier of soundproofing solutions

What type of Wall?
What type of Floor?
What type of Ceiling?
Back to Help, Info & Tips

What is the difference between airborne and impact noise?

understanding airborne and impact noise

 

The difference between airborne noise and impact noise lies in how the sound is generated and transmitted through a structure:

  1. Airborne Noise – This sound travels through the air and is transmitted through walls, floors, and ceilings. Examples include conversations, TV noise, and music. Airborne noise is tested by measuring the reduction in sound levels as it passes through a partition.
  2. Impact Noise – Sound generated by direct contact with a surface, typically on floors, such as footsteps, moving furniture, or dropped objects. It is tested by measuring the level of impact noise that transmits through a floor.

Part E Regulations airborne and impact values

  • Airborne Sound Insulation (Higher Value Required) – The higher the airborne sound insulation (measured in dB DnT,w + Ctr), the better the performance in reducing noise transmission. A higher value indicates better insulation against airborne sound.
  • Impact Sound Transmission (Lower Value Required) – The impact sound level (measured in dB L’nT,w) should be as low as possible, meaning less noise is transmitted through the floor.

This distinction in values ensures that airborne noise is well blocked while impact noise is minimised, creating a quieter living environment in multi-residential buildings.

Part E of the Building Regulations in England addresses the resistance to the passage of sound, setting minimum standards for sound insulation in buildings to ensure occupant comfort and privacy. Airborne and impact sound insulation requirements vary depending on whether the building is newly constructed or formed by a material change of use (e.g., conversions).

For New Build Dwellings (Purpose-Built Houses and Flats):

  • Airborne Sound Insulation:
    • Separating Walls and Floors: Must achieve a minimum of 45 dB DnT,w + Ctr. This means that the weighted standardised level difference, with a spectrum adaptation term, should be at least 45 decibels. A higher value indicates better performance in reducing airborne sound transmission.
  • Impact Sound Insulation:
    • Separating Floors: Must achieve a maximum of 62 dB L’nT,w. This refers to the weighted standardised impact sound pressure level, which should not exceed 62 decibels. A lower value indicates better performance in minimising impact sound transmission.

For Dwellings Formed by Material Change of Use (Conversions):

  • Airborne Sound Insulation:
    • Separating Walls and Floors: Must achieve a minimum of 43 dB DnT,w + Ctr. This is slightly relaxed compared to new builds, acknowledging the challenges in upgrading existing structures.
  • Impact Sound Insulation:
    • Separating Floors: Must achieve a maximum of 64 dB L’nT,w. This is also slightly relaxed compared to new builds.

These standards are outlined in Approved Document E, which provides detailed guidance on achieving compliance with Part E of the Building Regulations.

Dwelling-houses and flats – performance standards for separating walls, separating floors, and stairs that have a separating function Airborne sound insulation DnT,w + Ctr dB (Minimum values) Impact sound insulation L'nT,w dB (Maximum values)
Purpose built dwellings house & flats
Walls 45dB -
Floors & stairs 45dB 62
Dwelling-houses and flats formed by material change of use
Walls 43dB -
Floors & stairs 43dB 64
Rooms for residential purposes – performance standards for separating walls, separating floors, and stairs that have a separating function
Purpose built rooms for residential purposes
Walls 43dB -
Floors & stairs 45dB 62
Rooms for residential purposes formed by material change of use
Walls 43dB -
Floors & stairs 43dB 64

It’s important to note that these requirements are designed to ensure a reasonable resistance to sound transmission between adjoining dwellings, thereby enhancing the acoustic comfort of occupants. Compliance is typically verified through pre-completion sound testing unless an approved Robust Details construction method is used.
The full Approved Document E contains more detailed information, including guidance on construction details and testing procedures.

Download Part E Document

Get in touch

If you’d like any help or advice, or would like to chat to us, please call or fill out this form and we’ll be back in touch shortly