Power to Sheds, Garages & Outbuildings in HRM

Do I need a subpanel, or will one circuit do?

It depends entirely on what is going out there, and it is worth being honest with yourself about that at the start rather than upgrading in two years. One circuit is genuinely enough for lights and a couple of receptacles in a garden shed. It is not enough for a workshop.

A subpanel makes sense once there is more than one circuit’s worth of load, or once you want the ability to isolate things separately out there. It costs more in the feeder and the panel, and it saves you doing the whole job twice. The question to answer first is not “shed or garage” but “what gets plugged in”.

Overhead or underground?

Underground is tidier, is not in the way of anything, and does not care about the weather. It also means a trench, which is most of the cost and most of the disruption to a lawn. Overhead is quicker and cheaper and there is a span of cable across your garden for the rest of the building’s life.

Most people here go underground for anything permanent, and the deciding factor is usually what is between the house and the outbuilding. A driveway, mature tree roots or a rock shelf can change the arithmetic considerably, which is why the route gets looked at rather than measured on a map.

What about the trench?

The depth, the route and what shares the trench are all specified, and they are worth getting right the first time because the remedy for a trench at the wrong depth is another trench. Jamie will tell you the spec for your particular run before anybody puts a spade in.

If you are digging it yourself to save money, that is a reasonable plan and it works, as long as the conversation happens first. Call before you dig, whoever is doing the digging: what else is buried in a Nova Scotia garden is not always recorded and is occasionally someone else’s service.

Does the outbuilding need its own permit?

Two separate permits, and people routinely conflate them.

The wiring permit comes from Nova Scotia Power Inspection Services on the province’s behalf, as it does for any electrical work here. Running a feeder and a subpanel to a detached building is permitted, inspected work.

The building permit is HRM’s and it is about the structure, not the wiring. HRM requires a building permit for accessory buildings at or above 20 square metres, roughly 215 square feet, or more than one storey; smaller structures need a development permit. Those are their thresholds and they are worth confirming with HRM directly before you build, because they set them and they change them.

What if there is a car charger in the plan?

Say so early, because it changes the size of everything. A detached garage with a Level 2 charger in it is a materially different feeder from one with lights and a freezer, and it is the load most likely to expose a service that is already close to its limit.

It is also much cheaper to run the right feeder once than to run a modest one now and replace it when the car arrives. If a charger is even a possibility, the EV charger page covers the capacity side of it.

What it costs

Quoted, and the distance and the route are the cost. The electrical equipment at each end is fairly predictable; getting the cable from one end to the other is not. A garage twenty feet from the panel wall and a shed at the bottom of a long garden with a driveway in between are different jobs by a wide margin.

Digging your own trench genuinely reduces it. So does deciding the load properly at the start, because the feeder gets sized once.

Permits and inspection in Nova Scotia

Running a single branch circuit within the rating limits can fall inside the exemption in the Electrical Code Regulations, but a feeder and a subpanel do not, and either way the exemption only applies where a construction electrician does the work and keeps a record. Our guide to doing your own electrical work sets out the regulation’s wording, including the part most summaries leave out.

Permits and inspections come from Nova Scotia Power Inspection Services for the province, and the work is done to the 2024 Canadian Electrical Code.