Part E: sound insulation rules between London dwellings

When does it apply to domestic work?

Whenever a building is converted to create flats or rooms for residential purposes, and whenever new internal walls and floors are built within a new dwelling — where the internal standard is a laboratory value of 40 dB Rw for walls and floors between a bedroom and other rooms.

A loft conversion within a single house does not create a separating element and therefore does not trigger testing, though the internal 40 dB Rw standard applies to the new walls.

What is pre-completion testing?

For conversions, a sample of separating elements is tested before completion — normally one set per group of up to ten nominally identical constructions. Testing is by a UKAS-accredited or ANC-registered organisation, and a failure means upgrade and retest before the completion certificate is issued.

Which detail usually fails?

Flanking transmission through the external wall or a continuous joist, and unsealed service penetrations. A single unsealed soil pipe or a row of recessed downlights can lose 8 to 10 dB, which is the difference between a pass and a rebuild.

What does approved document e (sound) mean for a London project?

How approved document e (sound) plays out in Haringey: London Borough of Haringey (Haringey Council) maintains 29 conservation areas, the Highgate Village Conservation Area and the Muswell Hill Conservation Area among them, and an Article 4 direction is in force there, so permitted development cannot be assumed. Anyone dealing with approved document e (sound) at a Haringey address is therefore working to a £548 householder application decided in 8 weeks, or a £249 prior approval over 6 weeks where approved document e (sound) still qualifies.

Approved Document E (sound) at a glance

Common questions about approved document e (sound)

• Acoustic separation
• Building regulations
• House in multiple occupation (HMO)
• Approved Document B (fire safety)