Low-voltage design should begin during schematic design – at the same time the architect is establishing the building's floor plan, equipment room locations, and core layout. The earlier low-voltage requirements are defined, the more cleanly they integrate with the architectural and MEP design.
When architectural teams defer low-voltage design for too long, the decisions that most affect low-voltage infrastructure have already been made without low-voltage input, creating coordination gaps that surface as RFIs and change orders.
The sections below walk through what gets decided at each phase and what it costs to wait on low-voltage design. Learn when low-voltage design should start on a commercial building project and what happens when it's deferred to construction in this blog by TMC.
What’s Decided at Schematic Design?
Schematic design (SD) is where the decisions that most affect low-voltage infrastructure are made. Telecommunications room locations, equipment room placement, riser shaft design, and ceiling system type are all established during SD, so getting low-voltage requirements into those decisions, rather than adapting to them afterward, is the primary value of early engagement.
At schematic design, the low-voltage design consultant establishes a technology program that explains:
- What systems the project requires
- Where the primary infrastructure lives
- What the infrastructure requirements are
These decisions become guides for the architectural design and requirements for the MEP engineering scope.
What’s Coordinated at Design Development?
Design development (DD) is where low-voltage requirements move from the program to T-layer drawings. These are a dedicated set of drawings for IT, AV, and security that feed back into the other disciplines, influencing the MEP drawings where conduit, cable trays, and similar pathways are concerned, and the architectural drawings where the systems affect the building itself. That two-way coordination is exactly what design development is for.
This is where most low-voltage coordination problems are caught, and where they’re cheapest to fix. A conduit route that conflicts with a mechanical duct or an equipment room that’s too small for the required rack count are easier to resolve during design development with a drawing revision – but the same problems discovered during construction require field modifications and expensive rework.
What’s Finalized at Construction Documents?
Construction documents (CD) are where the low-voltage design consultant produces the final drawings and specifications that go out to bid. Division 27 and Division 28 specifications describe each system the project requires, to what performance standard, with what infrastructure, and under what installation conditions.
Complete, coordinated low-voltage construction documents let contractors price the scope accurately, without any gaps for assumptions or unknowns. The bid reflects the actual project.
What Happens When Low-Voltage Design Is Deferred?
Deferring low-voltage design to CD or to the construction phase often results in architectural and MEP teams making decisions that affect low-voltage infrastructure without low-voltage input. This can lead to issues like:
- Telecommunications rooms that are undersized or in the wrong location
- Equipment rooms that don’t have the power, cooling, or physical dimensions the systems require
- Conduit that hasn’t been routed where the cable runs need to go
Starting low-voltage design during SD eliminates costly problems like these, because the infrastructure is sized correctly from the beginning, and the construction documents reflect what the project actually requires.
Ready to learn more about how TMC approaches low-voltage design for architectural projects? Reach out today.
