The Architect's Guide to Electrical Coordination
Coordinating with an electrical engineer is a high-stakes balancing act. Misalignment leads to surface-mounted equipment on finished walls, substations that breach authority clearances, undersized service rooms, and fire-detection devices that don't comply. This guide serves as a coordination bridge, ensuring electrical and communications data are accurately integrated across your plans, from the incoming supply at the boundary to the last switch in the last room.
1. WHEN ARE ELECTRICAL ENGINEERS ENGAGED & FOR WHICH BUILDING CLASSES?
Timing: Engaged in Schematic Design / Design Development to establish the incoming supply strategy, calculate maximum demand, and reserve space for substations, main switchrooms, risers, and service rooms. They remain on board through Construction Documentation as load calculations, lighting, and devices are finalised.
Classes: All building classes. Coordination intensity scales with size and use; larger Class 2–9 buildings frequently require a dedicated substation or padmount, multiple switchrooms, riser shafts, and fire services, all of which consume planned floor area.
2. WHAT INFORMATION DO THEY PROVIDE, AND HOW DO YOU COORDINATE IT?
A. Incoming Supply & Main Service Routing
The Driver: The electrical engineer establishes the connection method, point of attachment, and incoming supply characteristics derived from the project’s calculated maximum demand. Once the entry point is locked, the engineer maps the incoming high-voltage (HV) and low-voltage (LV) underground conduit runs. Because these conduits compete for physical ground space with deep structural elements and gravitational wet services, you must actively lead the spatial coordination of the service trenches before any early works packages are issued.
Information Provided by the Electrical Engineer:
The physical point of entry at the property boundary, consumer mains sizing, and total number/diameter of incoming conduits.
The precise horizontal and vertical routing of the High Voltage (HV) supply paths leading into the on-site padmount, substation, or main switchroom.
The depth, bending radii, and bedding requirements for all heavy electrical conduit banks.
Architectural Cross-Check & Action:
The Early Works Overlay: Overlay the Electrical site plan, Hydraulic site plan, Civil grading, and Structural Foundation layout directly onto your Master Architectural Site Plan. You must track where services run into the building footprint to ensure deep electrical conduit banks do not physically intersect with gravitational sewer lines, stormwater pipes, or civil bio-retention basins.
The Sub-Structure Clash Test: Trace the physical path of the HV conduits from the boundary to the main switchroom. Cross-check this route against the structural engineering drawings to verify that the conduit depth completely clears all deep piling, capping beams, and strip footings. Where conduits must penetrate structural elements or floor slabs, verify that the structural engineer has detailed compliant, sleeved penetrations that do not compromise structural integrity.
The Service Trench Sequence: Cross-check the civil and landscape plans to ensure that deep service trenches do not undermine proposed retaining walls, fence footings, or heavy vehicle driveway pavements.
B. Substation & Padmount Siting
The Driver: When a padmount or substation is required on-site, the electrical engineer provides the requirements mandated by both the local supply authority and the Australian Standards. Because an authority easement permanently locks that footprint, you must actively cross-check these clearance boundaries against your architectural layouts.
Information Provided by the Electrical Engineer:
The specific separation metrics required to satisfy network environmental codes, electromagnetic field (EMF) rules, and structural fire safety.
The exact physical clearance zones needed around the unit for operational cabinet door swings, maintenance boundaries, and heavy vehicle crane access routes.
Architectural Cross-Check & Action:
The Environmental Boundary (Acoustic & EMF): Take the separation metrics provided by the engineer and cross-check your layouts against them to ensure the transformer enclosure stays a minimum of the specified distance (typically 4m) from any internal habitable spaces (such as bedrooms or living areas) to satisfy statutory acoustic hum and low-frequency EMF exposure codes.
Fire Propagation Boundary (AS 2067): Confirm the fire propagation boundary with the electrical engineer. Padmount transformers typically require a minimum 6 m separation from the building envelope.
FRL Alternative: Where a 6 m setback cannot be achieved, an FRL 120/120/120 concrete or masonry firewall may be used in accordance with AS 2067 and Energex requirements. Maintain a minimum 1 m clearance between the padmount and the firewall. Confirm the firewall’s extent with the electrical engineer if unsure.
The Authority Easement Footprint: Cross-check the final position against the network provider's mandatory easement boundaries. This zone must remain completely clear of any building overhangs, eaves, or balconies to satisfy the authority's "clear sky" requirement, ensuring a heavy crane can vertically extract and replace the unit during an emergency. Get these requirements from the electrical engineer if unsure.
C. Electrical & Communications Service Rooms: FRL & Separation
The Driver: Switchrooms, main distribution rooms, communications/data rooms, substation rooms, generator rooms, lift shafts, and the fire control room all attract fire-resistance and separation requirements under the NCC. These are easy to under-size and easy to mis-rate, and both errors are expensive to fix late.
Architectural Check:
Confirm and lock the FRL and separating-construction requirements for every electrical, comms, service, lift, and substation enclosure against the relevant NCC provisions for your project. Reflect these FRL requirements on the architectural fire-rating plan and partitions plan.
Where the requirement is unclear, ask the certifier and the electrical engineer to confirm the FRL; do not assume it. Mis-rated walls and doors around switch and comms rooms are a common late-stage rework.
Specify and reserve space for the actual wall system construction required to achieve the nominated FRL, rather than relying on a plan label to deliver the rating.
Locate the Fire Indicator Panel (FIP) and (where required) the fire control room early. Coordinate its FRL requirements, door swing, and clear space with the fire engineer and electrical engineer; retrofitting it into a finished foyer never goes well.
D. Equipment Sizing & Spatial Allocation
The Fit Test: Major electrical equipment must be drawn to scale into the space you've allocated, not represented by a generic dashed rectangle. Switchgear, distribution boards, an emergency generator, transfer switches, and a UPS all have real footprints, swing clearances, and ventilation needs.
Architectural Check:
Verify that the equipment sizes and access requirements are accounted for on the architectural floor plans.
Confirm dedicated risers are sized to fit every specified cable tray.
Cross-check the RCP and ceiling cavity so electrical cable trays don't clash with bulky mechanical ducts, structural beams, or hydraulic drainage falls. Where they do, resolve it before it eats into clear head height or forces an oversized bulkhead.
Appliances requiring services: Coordinate dishwashers, fridges/freezers, ovens, cooktops, hot-water units, and any tenant/feature appliances early, so the load schedule and switchboard are sized correctly rather than patched on site.
E. Lighting, power & Comms Devices.
The Driver: Coordinate lighting, power/comms, and fire-detection devices on reflected ceiling plans and wall elevations with architectural, mechanical, hydraulic (sprinkler), and structural elements.
Architectural Check:
Identify typical and feature lighting fixtures (ceiling and wall) on the RCP, plus exit and emergency lighting, and coordinate them with diffusers, sprinkler heads, and access panels.
Locate and verify all electrical and communication outlets, including power receptacles, data/telephone points, TV outlets, light switches, CCTV, security devices, and intercoms for all rooms, ensuring coordination with the furniture and joinery layout.
F. Dry Fire Services
The electrical engineer provides the information regarding dry fire services, which includes the location for all emergency lighting, smoke detectors, smoke/fire alarms, etc.
Action Checklist:
Cross-check the electrical RCP against the mechanical, hydraulic (sprinkler), and architectural RCPs for clashes.
Fire-Detection vs. Air Movement ("Fan Distance"): Smoke and heat detectors must be set back from mechanical supply/return-air outlets, diffusers, and ceiling fans so that air movement doesn't dilute smoke and delay activation (per AS 1670.1). Coordinate detector positions against the mechanical RCP early, and confirm the required minimum offset with the electrical engineer rather than spacing detectors on the architectural grid alone.
3. COMMON COORDINATION PITFALLS
The Padmount Exclusion-Zone Squeeze: Treating the substation as a leftover-corner item rather than designing its full clearance envelope. If a window, balcony, overhang, habitable room, or hydrant falls inside the authority's exclusion zone, or a fire barrier is triggered late, the building either loses planned area to an easement or forces an unbudgeted FRL 120/120/120 wall. Plot the zone before you fix the building footprint.
The Spatial Afterthought: Sizing electrical plant rooms or risers based on generic rules of thumb rather than scaled equipment footprints leads to oversized bulkheads, compromised clear head heights, or loss of saleable/useable floor space when the actual switchgear or UPS dimensions are finalised. Draw the real footprints early.
The Demolition Stall (Abolishment Trap): Assuming a demolition contractor can begin stripping a site immediately on day one without completing the formal utility connection abolishment process. This results in severe project delays and significant site safety hazards. Because abolishment runs through the retailer to the network provider (and the builder's pole runs through the contractor to the provider via the partner portal), authority lead times govern, not your program; lodge both requests early.
The FRL Fire-Drill: Failing to identify fire-rated service enclosures early. Missing an FRL requirement on an electrical service room means fire doors, fire-rated plasterboard, and specialised acoustic/fire dampening penetrations are missed in tender documents, leading to major budget blowouts. Confirm the FRL requirements with your fire engineer/certifier before issuing.
The Superseded File Trap: Coordinating against an outdated electrical site plan leads to misaligned conduit paths, undersized risers, clashing services and, at the boundary, an HV route that no longer matches the structural foundation plan. Always confirm you're working to the current issue before you coordinate.