Which AS/NZS 3000 maximum demand method should I use?

Use Table C1 for domestic dwellings and multi-unit residential, Table C2 for non-domestic installations with itemised loads, and Table C3 (energy-demand method) when floor-area and occupancy categories give a more reliable estimate than load itemisation.

Is the maximum demand calculation mandatory?

AS/NZS 3000:2018 Clause 2.2.2 requires that the maximum demand of every consumer's installation be assessed before sizing consumer mains, switchboards and submains. The Appendix C tables are the deemed-to-comply methods.

Can I add EV charging and battery loads to maximum demand?

Yes. AS/NZS 3000 Amendment 2 added explicit assessment rules for EV supply equipment, and battery storage loads must be included according to manufacturer continuous ratings. The ElecAS calculators include EV inputs in C1 and C2.

Which AS/NZS 3000 table do I use to calculate maximum demand?

Use Table C1 for single dwellings and multiple-dwelling installations (units, townhouses, apartments), Table C2 for non-domestic installations (offices, retail, industrial, hotels), and Table C3 for the energy-meter method on existing installations being extended. ElecAS provides a calculator for each.

Is solar PV subtracted from maximum demand under AS/NZS 3000:2018?

No. AS/NZS 3000 requires the consumer mains and submains to be sized for the no-PV case so they can carry full grid-import current if the inverter trips. PV generation is not subtracted from the Appendix C maximum demand result.

What is the minimum consumer mains current under AS/NZS 3000:2018?

Clause 2.2.2 imposes a 32 A minimum for the consumer mains of a single dwelling regardless of the Appendix C calculated demand. For multiple dwellings the minimum applies per dwelling and is summed with the appropriate diversity. The ElecAS C1 calculator applies the minimum automatically.

How do EV chargers affect maximum demand?

EV chargers are handled under AS/NZS 3000:2018 Clause 2.2.2(c). For one or two chargers in a single dwelling the full charger demand is added to the Table C1 / C2 result without diversity. For larger fleets where a primary load-management system limits simultaneous charging (e.g. 3 of 10 chargers at any time), the calculated demand may recognise that limit. Refer to the Electric Vehicle Council guidance for the load-control approach.

Can I use a load-recording method instead of Appendix C?

Yes. Table C3 (the energy-meter method) allows you to scale a calculated Appendix C demand against historical kWh use for an existing installation. The method is recognised under Clause 2.2 but cannot be used for greenfield installations where no historical data exists.

ElecAS

Maximum Demand Calculators

Choose Table C1, Table C2 or Table C3 maximum demand workflows for Australian electrical design calculations.

Why this page matters

Choose Table C1, Table C2 or Table C3 maximum demand workflows for Australian electrical design calculations. This static content is published so the canonical route has meaningful crawlable HTML even before the interactive application hydrates.

Who this page is for

Users selecting the correct maximum demand method for domestic, non-domestic and energy-demand projects.

Relevant standards

AS/NZS 3000 Table C1
AS/NZS 3000 Table C2
AS/NZS 3000 Table C3

What this tool helps with

Compare the three common maximum demand methods from one hub.
Choose the path that matches domestic, non-domestic or energy-demand inputs.
Move directly into the specific calculator needed for the installation.

How to calculate maximum demand for an Australian installation

Pick the right table — Use Table C1 for dwellings (single or multiple), Table C2 for non-domestic (commercial / industrial / mixed-use non-residential), and Table C3 for the energy-meter method on existing installations. The hub page links to each.
Group your connected loads — Group each load into the matching Appendix C row (lighting, socket-outlets, range / cooktop, water heater, motors, fixed A/C, EV charger, etc.). Use the connected installed load, not the demand.
Enter the dwelling count (Table C1) or floor area (Table C2) — Table C1 expressions change with dwelling count band (1, 2, 3–5, 6–20, 21–40, 41+). Table C2 uses load groups with explicit diversity expressions per row.
Apply EV charger and PV considerations — EV chargers are handled under AS/NZS 3000:2018 Clause 2.2.2(c) — calculated demand may recognise a primary load-management system that limits simultaneous charging. PV generation is NOT subtracted — the cable must be sized for the no-PV case.
Check the AS/NZS 3000 minimum current floor — AS/NZS 3000 Clause 2.2.2 imposes a 32 A minimum for single-dwelling consumer mains. The calculator applies the minimum automatically and flags it in the output.
Export the branded PDF — The PDF lists every Appendix C row used, the dwelling-count band or load-group expression, and the resulting per-row contribution — suitable for inclusion in a design submission package.

Maximum demand under AS/NZS 3000:2018 Appendix C — Tables C1, C2 and C3

What is maximum demand and why does AS/NZS 3000 require it?

Maximum demand is the highest current an installation is expected to draw on a sustained basis, calculated by applying diversity factors to the connected load. AS/NZS 3000:2018 Clause 2.2 requires that consumer mains, submains and the main switchboard be sized for the maximum demand of the installation — not the connected load — because real installations almost never draw their full connected load simultaneously.

Appendix C of AS/NZS 3000:2018 provides three tabulated methods: Table C1 for single and multiple dwellings, Table C2 for non-domestic installations (commercial, industrial, mixed-use, common services), and Table C3 for the energy-meter method that allows the calculated demand to be derated against historical kWh consumption.

Which table applies to which installation

Table C1 applies to consumer mains and submains serving any single dwelling or any group of dwellings (units, townhouses, apartments) including their common services where the common services demand is less than 10% of the dwellings demand. Loads are grouped into rows (lighting, socket-outlets, range, water heater, motors, A/C, EV chargers, etc.) with per-row diversity expressions for 1, 2, 3–5, 6–20, 21–40 and 41+ dwelling counts.

Table C2 applies to non-domestic installations — offices, retail, factories, hotels, schools, hospitals — and uses load grouping with different per-row diversity expressions. Table C3 applies the energy-meter method, which scales the calculated demand by historical kWh use; useful for existing installations being extended.

When the choice of table changes the result

A mixed-use building (ground floor retail, upper floors residential) requires Table C2 for the retail submain and Table C1 for the residential submains, with the common services submain summed at the main switchboard. EV chargers are handled under AS/NZS 3000:2018 Clause 2.2.2(c), which allows the calculated demand to recognise a primary load-management system that limits how many chargers operate simultaneously.

Solar PV generation is not subtracted from maximum demand for cable sizing under AS/NZS 3000 — the cable must be sized for the no-PV case so it can carry full grid-import current if the inverter trips. This is a common compliance trap that the ElecAS C1 and C2 calculators flag automatically.

How ElecAS implements Appendix C

The ElecAS suite implements all three tables — Table C1 (single dwelling and multiple-dwelling), Table C2 (non-domestic load grouping) and Table C3 (energy-meter method) — with worked examples drawn from AS/NZS 3000:2018 Appendix C. Each calculator emits a branded PDF citing the row, expression and dwelling-count band used for every load, so the calculation can be re-verified clause-by-clause during compliance review.

Use the hub page to pick the right table for your installation; each linked calculator runs the full Appendix C arithmetic and validates against the AS/NZS 3000 minimum current rules (e.g., 32 A minimum consumer mains for any single dwelling under Clause 2.2.2).

Reviewed by

Wisam Tozah — Associate Electrical Engineer. B.Eng (Electrical), MIEAust, CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE(Aus). LinkedIn.

Frequently asked questions

Which AS/NZS 3000 maximum demand method should I use?: Use Table C1 for domestic dwellings and multi-unit residential, Table C2 for non-domestic installations with itemised loads, and Table C3 (energy-demand method) when floor-area and occupancy categories give a more reliable estimate than load itemisation.
Is the maximum demand calculation mandatory?: AS/NZS 3000:2018 Clause 2.2.2 requires that the maximum demand of every consumer's installation be assessed before sizing consumer mains, switchboards and submains. The Appendix C tables are the deemed-to-comply methods.
Can I add EV charging and battery loads to maximum demand?: Yes. AS/NZS 3000 Amendment 2 added explicit assessment rules for EV supply equipment, and battery storage loads must be included according to manufacturer continuous ratings. The ElecAS calculators include EV inputs in C1 and C2.
Which AS/NZS 3000 table do I use to calculate maximum demand?: Use Table C1 for single dwellings and multiple-dwelling installations (units, townhouses, apartments), Table C2 for non-domestic installations (offices, retail, industrial, hotels), and Table C3 for the energy-meter method on existing installations being extended. ElecAS provides a calculator for each.
Is solar PV subtracted from maximum demand under AS/NZS 3000:2018?: No. AS/NZS 3000 requires the consumer mains and submains to be sized for the no-PV case so they can carry full grid-import current if the inverter trips. PV generation is not subtracted from the Appendix C maximum demand result.
What is the minimum consumer mains current under AS/NZS 3000:2018?: Clause 2.2.2 imposes a 32 A minimum for the consumer mains of a single dwelling regardless of the Appendix C calculated demand. For multiple dwellings the minimum applies per dwelling and is summed with the appropriate diversity. The ElecAS C1 calculator applies the minimum automatically.
How do EV chargers affect maximum demand?: EV chargers are handled under AS/NZS 3000:2018 Clause 2.2.2(c). For one or two chargers in a single dwelling the full charger demand is added to the Table C1 / C2 result without diversity. For larger fleets where a primary load-management system limits simultaneous charging (e.g. 3 of 10 chargers at any time), the calculated demand may recognise that limit. Refer to the Electric Vehicle Council guidance for the load-control approach.
Can I use a load-recording method instead of Appendix C?: Yes. Table C3 (the energy-meter method) allows you to scale a calculated Appendix C demand against historical kWh use for an existing installation. The method is recognised under Clause 2.2 but cannot be used for greenfield installations where no historical data exists.