Dwelling Service Load Calculator

CSA C22.1:24 Rule 8-200 / Table 14 demand factors for single dwellings, row housing, and apartments. Calculates basic load, heating, A/C, EVSE, and total service/feeder demand.

Inputs

Basic load: 24,000 W if ≥ 80 m², else 14,400 W

If both heating & A/C, only the greater counts (Rule 8-202 3)

Results

Total Calculated Demand

watts

Basic Load — W
Heating/A/C (greater) — W
Range — W
EVSE — W
Other Loads — W

Service Current

A @ 240V

Recommended Size

A

CSA C22.1:24 Reference

Rule 8-200, Table 14

How It Works

Rule 8-200 (Single Dwelling): The calculated load is the basic load (24,000 W for ≥ 80 m², 14,400 W for < 80 m²) plus the greater of electric heating or A/C, plus electric range, plus EVSE, plus other connected loads. No demand factor is applied to a single dwelling.

Rule 8-202 (Multiple Dwellings): For row housing or apartments, the calculated load per unit is determined per Rule 8-200, then demand factors from Table 14 are applied. The first unit uses 100%, and additional units use 65% of the sum of the next two units' loads.

Service current = Total Demand (W) ÷ System Voltage (240 V for single-phase). Standard breaker sizes: 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 500, 600, 800, 1000 A. Round up to next standard size.

Reference Table

Table 14 — Watts/m² and Demand Factors

Watts per square metre and demand factors for services and feeders for various types of occupancy. See Rules 8-002 and 8-210.

Type of occupancy Watts/m² Insulated service conductors (%) Feeders (%)
Store, restaurant 30100100
Office — First 930 m² 5090100
Office — All in excess of 930 m² 507090
Industrial and commercial 25100100
Church 10100100
Garage 10100100
Storage warehouse 57090
Theatre 307595
Armouries and auditoriums 1080100
Banks 50100100
Barbershops and beauty parlours 3090100
Clubs 2080100
Courthouses 20100100
Lodges 1580100

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