SSOT v3.7 · Project Reference · Acoustic Design Basis

Construction Trade Sequence

Reference sequence for structural verification, acoustic shell construction, fit-out, and final commissioning. Hold points [HP] must be signed off before dependent work can proceed. Acoustic-critical scope remains tagged [AC].

Total Duration
35–50 days
Hold Points
4 formal sign-offs
Parallel Streams
MEP + Acoustic
Final Gate
Certificate issue
Hold Point / Sign-off MEP Contractor Acoustic Contractor AV / Joinery

10-Phase Flowchart

Parallel Swim Lanes

MEP rough-in and acoustic works are shown as coordinated swim lanes. Hold points sit outside the trade lanes and block downstream activities until written sign-off is issued.

MEP contractor lane Acoustic / fit-out lane Consultant / hold points Phase 1 [HP] Structural + Site Verification Who: Structural engineer + MEP What: Slab 45 kg/m² check + survey/protect W/N MEP corridor (SP-02) Duration: 1–2 days Phase 2 MEP Rough-In Who: MEP contractor What: Sleeves, duct rough-in, electrical rough-in. Duration: 5–7 days Phase 3 Acoustic Wall Construction Who: Acoustic contractor What: W3–W6 framing, clips, wool, gypsum, GG. Duration: 8–12 days Phase 4 [HP] Penetration Sealing Who: Acoustic contractor What: Tremco Fyre-Sil both faces before ceiling. Duration: 2 days Phase 5 Float Floor Who: Acoustic contractor What: Sylomer, 2-layer T&G, 10 mm gap [AC] Duration: 4–6 days HP INSPECT Phase 6 Acoustic Ceiling Who: Acoustic contractor What: T-grid, Rockwool, tiles, plenum barriers. Duration: 3–4 days Phase 7 MEP Fit-Out Who: MEP contractor What: Silencers, outlets, lighting, HVAC connections. Duration: 4–5 days Phase 8 Acoustic Treatment Who: Acoustic contractor What: Panels, bass traps, QRD, OW-1 glazing install. Duration: 3–4 days Phase 9 Equipment & Doors Who: AV contractor + joinery What: D1–D3 + D5 hung, racks terminated, desk installed. Duration: 3–5 days Phase 10 [HP] Commissioning Who: Acoustic consultant What: RT60, NC, STC tests. Certificate issued. Duration: 1–2 days Total indicative programme: 35–50 working days

Hold Points

4 Mandatory Sign-Offs

HP-1 Structural Verification

Written confirmation from the structural engineer is required before Sylomer, plywood, or finish-floor loads are introduced.

Phase 1

Existing MEP Corridor (SP-02)

Survey + protect the EXISTING high-level services along the west/north edge — insulated duct, spiral ducts, cable trays, live cabling, smoke detection (S3-SITE-TRUTH §4, photo IMG_1291). They sit in the future audio-side 76 cm plenum zone: coordinate plenum + silencer routing BEFORE any ceiling work; keep live services live; relocations only per approved MEP shop drawing.

Phase 1

HP-4 Penetration Sealing

All wall penetrations must be sealed and inspected before ceilings close the plenum. No ceiling works advance until sealing is accepted.

Phase 4

HP-5 Float Floor Gap Check

The 10 mm perimeter gap, backing rod, and Tremco sealant must be inspected before vinyl or carpet finishes are installed [AC].

Phase 5

HP-10 Commissioning

Client handover occurs only after RT60, NC, and field transmission results are documented and the acoustic certificate is issued.

Phase 10

Trade Handoffs

Interface Notes
FromToCritical Interface
Structural engineerAcoustic contractorFloat floor dead load approval before Sylomer order release
MEP contractorAcoustic contractorOversized sleeves and 10 mm annular gaps delivered before wall closure
Acoustic contractorMEP contractorPenetration sealing and plenum barriers completed before final connections
Acoustic contractorAV / joineryWalls, ceilings, and treatment complete before desk, racks, and door hardware adjustments
All tradesConsultantFinal commissioning relies on fully installed finishes, silencers, doors, and treatment