ELV containment is routinely the last trade modelled and the first clashed on Australian construction projects — a pattern that repeats project after project not because ELV design is inherently harder to coordinate, but because it's structurally disadvantaged in most design programmes by the time it gets modelled.
Why ELV Clashes More Than Other Trades
ELV containment is frequently modelled later in the design programme than hydraulics, HVAC ductwork and structural elements, which are typically modelled and effectively locked earlier in the coordination process. By the time ELV containment routing is added to the model, the ceiling void space it needs to navigate has often already been substantially claimed by other services, forcing ELV routing into whatever constrained space remains. This isn't a technical modelling problem — it's a sequencing problem, and the fix is procedural (bringing ELV modelling forward in the coordination programme) as much as it is a Revit technique.
LOD Expectations for Security and Comms Devices
- Security and comms devices typically need LOD 300-350 for coordination purposes — accurate size, location and connection points sufficient for clash detection and construction sequencing.
- LOD 400 fabrication-level detail is usually unnecessary for device placement and adds modelling effort without proportionate coordination benefit for most ELV device types.
- Containment (tray, conduit) generally needs higher-fidelity modelling than individual devices, since it's containment routing — not device placement — that drives the majority of ELV clashes with other trades.
Tray-Routing Priorities Against Hydraulics and HVAC
When ELV containment genuinely competes for the same ceiling void space as hydraulic pipework or HVAC ductwork, a documented routing priority — agreed with the broader MEP coordination team, not decided unilaterally by whichever trade models last — avoids the same conflict resurfacing repeatedly through the coordination process. In practice, larger-diameter hydraulic and ductwork services often have less routing flexibility than ELV containment (which can generally take a less direct path more easily), which is a useful default priority principle, though it should be confirmed against the specific project rather than applied blindly.
Design takeaway: Bring ELV containment modelling forward in the coordination programme rather than treating it as the trade that fits into whatever space remains, and establish an explicit routing priority with the MEP coordination team before clashes accumulate — this is a scheduling and process fix as much as a modelling technique.
Navisworks Test Suites That Catch Congestion Early
Beyond simple geometric clash detection, an effective Navisworks test suite for ELV checks minimum separation clearances between ELV containment and other services — particularly high-voltage cabling, where separation is a compliance requirement rather than just a coordination preference — plus ceiling-void congestion in high-density zones and access clearance for maintenance around ELV equipment. These checks catch coordination problems that pure geometric clash detection misses, since a technically non-clashing but overly congested ceiling void is a real construction and maintenance problem even without a hard geometric intersection.
Frequently Asked Questions
Why does ELV containment routinely clash more than other trades on Australian projects?
ELV containment is frequently modelled later in the design programme than hydraulics, HVAC ductwork and structural elements, which are typically modelled and locked earlier — by the time ELV containment routing is added, the ceiling void space it needs to navigate has often already been substantially claimed by other trades, forcing ELV into the remaining, more constrained space.
What LOD should security and comms devices be modelled to on an Australian project?
Security and comms devices typically need LOD 300-350 for coordination purposes — accurate size, location and connection points sufficient for clash detection and construction coordination — rather than LOD 400 fabrication-level detail, which is usually unnecessary for device placement and adds modelling effort without proportionate coordination benefit.
What should a Navisworks clash test suite for ELV specifically check?
Beyond simple geometric clash detection, an effective test suite checks minimum separation clearances between ELV containment and other services (particularly high-voltage cabling, where separation is a compliance requirement not just a coordination preference), ceiling-void congestion in high-density zones, and access clearance for maintenance around ELV equipment — issues that pure geometric clash detection alone won't necessarily catch.