How Much Does Electrical Design Cost for a Commercial Building?
The Short Answer
Electrical design fees for commercial buildings in Australia range from $2,000 for a small fitout to $60,000+ for a multi-storey development. Most projects fall in the $6,000–$20,000 range. These are engineering design fees for drawings, calculations, and documentation required for certification and construction. They do not include the cost of equipment or installation. Design fees are typically 3–8% of the electrical installation cost.
Typical Fee Ranges by Project Type
Small Commercial Fitout (under 500 sqm)
Office, retail, or food and beverage fitout. $2,000–$6,000. Includes power distribution layout, lighting design, emergency and exit lighting, switchboard sizing, maximum demand calculation, and specification. Turnaround: 2–3 weeks.
Medium Commercial (500–2,000 sqm)
Multi-tenancy office, large retail, gym, restaurant. $6,000–$20,000. More complex power distribution, sub-metering for Section J compliance, detailed lighting power density calculations, and RCD protection layout. Full documentation set for CC. Turnaround: 3–6 weeks.
Multi-Storey Development (2,000+ sqm)
Mixed-use, residential towers, large commercial. $20,000–$60,000+. Main switchboard and distribution board design, riser coordination, cable sizing with voltage drop analysis per AS/NZS 3008, staged documentation across DA, CC, and construction. Turnaround: 2–6 months depending on project program.
Specialist Additions (any size)
Lightning protection, solar PV integration, surge protection, data and communications, security systems, EV charging provisions. Add $2,000–$15,000 depending on scope. These are quoted separately because they require specific calculations and compliance documentation beyond the base electrical design.
What Drives the Cost
- Building size and number of floors – more area means more circuits, more distribution boards, more design work
- Maximum demand – higher electrical loads require larger switchboards, bigger cables, and more detailed calculations per AS/NZS 3000
- Section J lighting compliance – lighting power density calculations and controls design add to the scope
- Sub-metering requirements – NCC Section J mandates sub-metering for energy monitoring in most commercial buildings
- New build or refurbishment – existing buildings have unknown cable routes, legacy switchboards, and more survey work
- Specialist systems – lightning protection, solar PV, EV charging, and security all add distinct design packages
- Documentation scope – DA-level vs full CC documentation vs construction-phase support
- Multi-discipline packages – bundling electrical with mechanical, hydraulic, and fire reduces per-discipline cost
What You Get for the Fee
- Power distribution design – switchboard schedules, circuit layouts, and single line diagrams
- Lighting layout – luminaire selection, lux level calculations, and controls
- Emergency and exit lighting – compliance with AS/NZS 2293
- Maximum demand calculations – per AS/NZS 3000 Wiring Rules
- Cable sizing and voltage drop – per AS/NZS 3008
- Section J energy compliance – lighting power density, sub-metering, and controls documentation
- RCD protection layout – residual current device selection and circuit allocation
- Specification for tendering and construction
- Coordination with mechanical, hydraulic, and fire services
- Response to contractor queries during construction
Who Needs to Know What
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References
- AS/NZS 3000:2018, Electrical installations (known as the Australian/New Zealand Wiring Rules)
- AS/NZS 3008.1.1:2017, Electrical installations – Selection of cables – Cables for alternating current voltages up to and including 0.6/1 kV
- National Construction Code 2022, Section J – Energy Efficiency
- AS/NZS 3010:2017, Electrical installations – Generating sets