Do I need to upgrade the floor if I'm converting a flat?

Yes — Building Regs Part E applies to flat conversions ('material change of use'). New flats must meet 62dB L'nT,w for impact + 45dB DnT,w airborne. Floor build-up + ceiling typically requires major intervention — Level 3 solution standard. Sound test required at completion to demonstrate compliance — failure means re-work.

Will replacing my floor finish help?

Carpet over good underlay achieves Part E existing dwelling limit (62dB L'nT,w) without other intervention. Wood/tile floor requires acoustic underlay + ideally floating floor system. Don't lay wood/tile directly over joists in an upper-floor London room — neighbours/family below will complain. Engineered wood specifically marketed 'quiet' (8mm underlay + wear layer) achieves 18–24dB improvement.

How do I test acoustic performance?

Pre-completion sound test: BS EN ISO 717-2 method, certified acoustic consultant. Tapping machine on floor, microphone in room below, measures L'nT,w. Cost £350–£950 per test. Mandatory for flat conversions (Part E compliance). Optional for upper-floor renovations in single dwellings (useful for design verification on premium projects).

Impact Noise Floor London 2026 | Builderr

How Is Impact Noise Through Floors Managed in a London Renovation?

London floor impact noise management targets Building Regs Part E maximum L'nT,w 62dB existing dwellings / 64dB new builds. Solutions: acoustic underlay (5–10mm rubber/fibre under floor finish), resilient batten + floating floor (15–25mm acoustic mat + plywood + finish), isolated suspended ceiling below. Cost £45–£185/m². Critical in flat conversions and upper-floor master suites above living rooms. Wood floor over joist most problematic; concrete floors better baseline.

Impact noise typology

Impact noise: footfalls, dropped objects, child play, furniture movement. Transmitted through floor structure as vibration; radiated as airborne sound in room below. Subjectively very disturbing — high-frequency clatter, low-frequency thuds. Measured as L'nT,w (impact sound pressure level weighted) — lower better. Untreated wood floor on joist over plasterboard ceiling: 72–82dB — fails Part E. Carpet on underlay over same floor: 58–64dB — passes existing Part E (62dB max), close to new build limit. Tiled or wood floor in flat above another flat: nightmare scenario without acoustic treatment — 80–90dB impact noise reported in complaints.

Solutions by intervention level

Level 1 (minimal — within existing floor finish): acoustic underlay between subfloor + finished floor. 5–10mm rubber/fibre underlay (Quietfloor, Sylomer, Hush HD1012) under engineered wood, laminate, vinyl, tile. Improvement: 6–14dB. Cost £25–£65/m² supplied + installed. Quick retrofit; preserves existing structure. Level 2 (replace floor build-up): resilient batten + floating floor. Existing joists topped with 25mm acoustic mat (Hush HD1014, Regupol), 25mm batten + 18mm plywood + finish above. Improvement: 14–22dB. Cost £85–£185/m². Level 3 (full acoustic floor + ceiling — flat conversion standard): Level 2 floating floor above + independent isolated ceiling below (suspended on resilient hangers, 100mm rockwool quilt in void, 2×15mm acoustic plasterboard ceiling). Improvement: 22–32dB. Cost £155–£285/m² combined floor + ceiling. Achieves Part E flat conversion target. Floating floor critical detail: no rigid fixings between floor and structure; perimeter sealed but not bridged.

Materials and detailing

Acoustic underlays: rubber-fibre composite (Quietfloor 5mm — 14dB improvement), Sylomer R (vibration isolation, 8–12dB), Hush HD1012 (12dB), Tecsound 100 (mass-loaded vinyl layer). Resilient battens: T&G with rubber underside (Regupol Sonus Core, Hush PNB) provide both spring and damping. Isolated ceiling hangers: Resilient Bar (acoustic clip + furring channel) decouples ceiling from joists — eliminates flanking. Floor finish choice: carpet absorbs impact at source (best); wood/tile/vinyl require underlay to manage. Tile on suspended floor most problematic — impact noise transmission worst-case. Tile on concrete acceptable. Perimeter detail: floating floor must not contact wall — 6mm gap with foam isolation strip, covered by skirting (skirting nailed to wall, not floor). Stair noise: under-stair acoustic absorbent (50mm rockwool in stringer + soffit board).