An ELV project is rarely a single drawing. A building may have CCTV cameras, access control doors, structured cabling outlets, fire alarm devices and public address speakers, all sharing the same ceilings, risers and containment. Each system needs its own layout, and the layouts must agree with each other and with the architectural and mechanical drawings.

This article explains the role of CAD in ELV design, the layouts and schedules a typical project needs, how drafting supports coordination, and how to prepare a clear scope for outsourced ELV drafting. It focuses on drawings and documentation. Engineering calculations, code compliance and professional approval are separate responsibilities, and we explain where that boundary sits.

The Role of CAD in ELV Design

The design of an ELV system involves decisions about coverage, capacity, routing and integration. CAD drawings record those decisions so that installers, commissioning engineers and the client can see what has been designed. Good drawings also reduce variations on site, because quantities, routes and device positions are defined before installation.

For building services, CAD is also the common language across disciplines. A ceiling plan shows detectors, speakers and cameras next to lighting and diffusers, which is where most clashes are found.

CCTV Camera Layouts and Coverage Coordination

CCTV layouts show camera positions, orientation, field of view references and mounting heights, together with the cable routes back to recorders or network switches. Drafting can present this clearly, but the coverage objectives and camera selection must come from the system design. Coordinate camera positions with lighting, signage and structural features, and check that mounting points exist on the architectural base.

Access Control Layouts and Door Schedules

Access control drawings show door positions, reader and lock locations, door controllers, power supplies and cable routes. A door schedule records each door reference, its function, hardware, reader type and controller. The schedule must match the plans, and any change to door hardware must be reflected in both. Confirm door numbering with the architect at the start, because renumbering later creates work across every drawing.

Structured Cabling and Telecom Layouts

Structured cabling drawings show outlet positions, horizontal routes, containment, telecom rooms and rack layouts. Cable schedules link each outlet to its patch panel port. Plans should show the containment capacity and separation from power cabling where routes run close together, following the applicable cabling standard for the project. Our structured cabling design service covers the design side of these layouts.

Fire Alarm Layouts and Relevant Documentation

Fire alarm layouts show detector, call point, sounder and control panel positions, together with cable routes and zone boundaries. Drafting must not change zoning or device positions without the design engineer's approval. Fire alarm drawings are often subject to specific approval and certification requirements, which vary by jurisdiction, so the documentation should follow the requirements in force for your project. More detail on the design side is in our fire detection and alarm design page.

PA/VA and Other Applicable ELV Layouts

Public address and voice alarm layouts show loudspeaker positions, zone arrangements, amplifier locations and cable routes. Speaker positions depend on acoustic objectives and the design's coverage calculations, so drafting should record those positions rather than invent them. Our PA/VA design service describes the design approach in more detail.

Riser Diagrams, Schematics, Rack Layouts and Cable Schedules

Four types of document commonly complement the plans:

  • Riser diagrams: vertical distribution of cabling and equipment between floors.
  • Schematic diagrams: functional connections between system components, without geographic detail.
  • Rack layouts: equipment arrangement within cabinets, including U positions and patch panel allocations.
  • Cable schedules: reference, origin, destination, type and route for each cable.

These documents should cross-reference each other. A cable reference on a plan should be traceable to the schedule, the rack and the riser.

Coordination With Architectural and MEP Drawings

ELV coordination uses the same approach as other building services. Agree the base drawing and its revision, set common levels, and record the base revision used on each ELV sheet. Check clearances around ceiling mounted devices and containment routes at key points, and log clashes for resolution at coordination meetings. Where ELV containment shares routes with power or mechanical services, confirm separation requirements with the design engineer.

Drawing Quality Assurance

ELV drawing sets benefit from a checklist applied before issue. A practical list includes:

  • Device counts on plans match the schedules
  • Cable references match between plans, schedules and riser diagrams
  • Door numbers match the architectural base and the door schedule
  • Rack elevations match the equipment list
  • Legends and symbols match the project standard
  • Revision block and drawing register are updated

How to Prepare a Clear Scope for Outsourced ELV Drafting

A useful scope for outsourced ELV drafting includes:

  1. The systems included, and any systems excluded
  2. The list of drawings and schedules required
  3. The base drawings, their revisions and where they are held
  4. The symbol library, drawing standard and file formats
  5. Which design decisions are supplied by the engineer
  6. The number of review rounds and the approval route
  7. The programme, including the date for the first issue

Drafting Support vs Engineering Responsibility

Drafting support documents the design; it does not replace the responsibilities of the engineer of record. Calculations, code compliance, equipment selection, system performance and professional approval remain with the qualified engineer. A drafting partner should be clear about this boundary in writing, and should raise questions when information is missing rather than assume the answer.

To discuss ELV drawings, layouts or schedules for your project, contact ASDV Consultant through our contact page.

Frequently Asked Questions

Typical ELV drawing sets include system layouts on floor plans, riser diagrams, schematic or block diagrams, rack and cabinet elevations, cable and equipment schedules, and details for mounting and containment. The exact list depends on the systems included and the contract. Confirm the list with the design engineer before drafting begins.
Drafting records the system design. Camera positions, coverage, door arrangements and cable routes should be decided by the qualified designer or engineer responsible for the system, then documented by the drafter. A drafting provider can suggest presentation improvements but should not be relied on for system design decisions without a clear scope.
ELV layouts depend on room positions, ceiling heights, door locations and structural constraints. If the architectural base changes, camera positions, door details and containment routes can become incorrect. Coordination with the base drawings and a clear revision reference prevents this.
A cable schedule typically records the cable reference, origin and destination, cable type, length or route reference, and the system it serves. Schedules should match the layouts and the containment drawings, and must be updated whenever routes change.
Yes. Riser diagrams show the vertical distribution of cabling and equipment between floors. Drafting can produce the diagram from the design information, including rack elevations and patch panel allocations, provided the design information is supplied and agreed.
Define the systems, the drawing list, the base drawings and their revisions, the format, the standard, the number of review rounds, and who answers queries. Make it clear which design decisions remain with your engineer. A short scope document avoids most disputes.

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