Part E Wall & Floor Sound Reduction
Wall and floor construction specifications to meet Approved Document E, including Robust Details, construction types, and laboratory Rw ratings for common separating wall and floor builds.
Separating Wall Types (AD-E Section 1)
| Wall Type | Construction | Typical Rw (dB) | AD-E Reference |
|---|---|---|---|
| Type 1 — Solid masonry | Dense block (min. 375 kg/m² mass), 13 mm plaster each side | 53-56 | Section 1, E-WT-1 |
| Type 2 — Cavity masonry | Two leaves of block with 75 mm cavity, butterfly ties, plaster finish | 55-58 | Section 1, E-WT-2 |
| Type 3 — Masonry between IWL | Dense or lightweight block with independent wall linings (IWL) each side | 55-60 | Section 1, E-WT-3 |
| Type 4 — Timber/steel frame | Twin independent frames, min. 200 mm total depth, mineral wool, 2 x plasterboard each face | 55-62 | Section 1, E-WT-4 |
Separating Floor Types (AD-E Section 2)
| Floor Type | Construction | Airborne Rw (dB) | Impact Ln,w (dB) |
|---|---|---|---|
| Type 1 — Concrete with soft covering | Concrete slab min. 300 kg/m², resilient covering (carpet + underlay) | 52-55 | 60-65 |
| Type 2 — Concrete with floating floor | Concrete slab with floating screed or platform on resilient layer | 55-58 | 52-58 |
| Type 3 — Timber with ceiling treatment | Timber joists with mineral wool, floating platform, independent ceiling | 50-55 | 55-62 |
| Type 3.1 — Engineered timber joist | I-joists or metal web with enhanced ceiling, floating floor | 52-57 | 52-58 |
Robust Details — Current Types
| RD Type | Element | Description |
|---|---|---|
| E-WM-1 to E-WM-24 | Masonry separating walls | Various block types, cavity/solid, wet/dry lining |
| E-WT-1 to E-WT-8 | Timber frame separating walls | Twin frame with board linings |
| E-FC-1 to E-FC-14 | Concrete separating floors | Various concrete types with ceiling and floor treatments |
| E-FT-1 to E-FT-6 | Timber separating floors | Timber joist with floating floor and independent ceiling |
Scotland & Northern Ireland
Scotland uses Technical Handbook Section 5 (Noise) with broadly similar performance targets but different approved constructions. Northern Ireland follows Technical Booklet G. Robust Details are accepted in England and Wales only — Scotland and Northern Ireland require testing or approved constructions per their own standards.
Related Calculators
Use the Sound Insulation Calculator for acoustic performance estimates. See the Part E Acoustic Ratings page for the performance targets.
Always check the latest edition of Approved Documents on the Planning Portal (planningportal.co.uk) as regulations are updated periodically.
How We Calculate This
Frequently Asked Questions
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Last updated: April 2026
All calculations are estimates. Verify with your supplier.