Load Calculations for Row-Housing

The following bulletin provides guidance on the application of rules pertaining to the 2024 BC Electrical Code. The requirements of local municipal authorities having jurisdiction may vary. Installers should consult with local authorities having jurisdiction, prior to undertaking work, to determine their requirements.

Scope:

This Bulletin provides clarification on rule 8-200 2), the calculation of the minimum ampacity of service or feeder conductors supplying two or more dwelling units of row-housing and includes single dwellings with secondary suites. (Note: Where it is intended to incorporate a secondary suite in a single dwelling, installers are advised to consult with the local authority having jurisdiction for Building Code requirements.)

Code definitions related to Rule 8-200 2)

Single dwelling - a dwelling unit consisting of a detached house, one unit of a row house, or one unit of a semi-detached, duplex, triplex or quadruplex house.

Dwelling unit - one or more rooms for the use of one or more persons as a housekeeping unit with cooking, eating, living, sleeping, and sanitary facilities (see Suite).

Suite - a single room or series of rooms of complementary use operated under a single tenancy, including dwelling units and individual guest rooms in motels, hotels, boarding houses, rooming houses, and dormitories.

Row-housing - This is not defined in the BC Electrical Code nor the BC Building Code. The local authority having jurisdiction for the BC Building Code may have by-laws that provide a definition. Typical examples of row-housing include: Duplexes, triplexes, quadruplexes, townhouses, and single dwellings with a suite.

When calculating the minimum ampacity of a service or feeder conductors supplying two or more dwelling units of row housing, 8-200 2) requires the use of a greater value from 8-200 1) a) or b), and application of the demands from 8-202 3) a) i) to v) plus the requirements of Rule 8-202 3) b) to e).

For buildings where units are 80m² or more:

• 24,000 W is the minimum allowed load used in the
• Where the calculated load exceeds 24,000 W, the calculated load value must be For buildings where units are less than 80m².
• 14,400 W is the minimum allowed ampacity of the feeder or
• where the calculated load exceeds 14,400 W, the calculated load value must be

In addition to the minimum conductor ampacity, the calculation determines the required rating of the busbar in a multi-gang meter base where one is used.

Note: In the 26th edition of the 2024 Canadian Electrical Code, Rule 8-202 3) d) does not address calculations of combined electric vehicle supply equipment (EVSE) loads when electric vehicle loads are supplied from panelboards of individual dwelling units. 8-202 3) a) excludes EVSE loads however only EVSE loads not supplied by a panelboard within a dwelling unit were added back into the calculation for 8-202 3) d). When EVSE loads supplied from a dwelling unit panel board are not added back into the total calculated load, there is a safety concern as it may result in the selection of consumer service equipment with an inadequate rating and may be non-compliant with other rules such as 8-104. 

The Section 8 technical sub-committee is aware of this oversight and is working on a correction. As CSA’s intent for Rule 8-202 3) Item d) was to apply to installations when electric vehicle supply equipment is either supplied from a panelboard installed in a dwelling unit or from a panelboard installed outside of a dwelling unit, we will be continuing to enforce the rule as we have in the past and with the knowledge that the correction is being made by CSA.

In the next edition of the code, Rule 8-202 3) d) is expected to read as “except as permitted by Rule 8-106 10) or Rule 8-106 11), any electric vehicle supply equipment loads shall be added with a demand of 100%; and”

Download PDF below for full details.

Vicky Kang
Manager, Energy
Provincial Safety Manager, Electrical

References:
Safety Standards Act
Electrical Safety Regulation
Safety Standards General Regulation