Rooftop solar installation

A residential solar installation in Ottawa is four jobs in sequence: a structural review, a building permit or a documented exemption, an electrical installation under the Ontario Electrical Safety Code, and a connection agreement with your distributor. The panels on the roof are the easy part. Most of the elapsed time is paperwork, and most of the ways a project goes wrong are in that paperwork.

Step one: a professional engineer looks at your roof. This is not optional in Ottawa and it surprises most homeowners. The City's position is that the design of solar collector systems and the on-site field review of their installation must be undertaken by a professional engineer licensed in the Province of Ontario (City of Ottawa, Solar collector systems). A building permit is separately required once the collector face area reaches 5 square metres, which almost any useful array does. Low-rise housing can be exempt, but only where the system is flush mounted with no ballast and an Ontario-licensed engineer has assessed the existing roof as being in good structural condition. Either route runs through an engineer.

Step two: the roof itself. An array is designed for twenty-five years and asphalt shingles in this climate are not. If your shingles have more than about eight years on them, reroof first, because removing and reinstalling an array later costs thousands. Orientation and shading are assessed at the same visit: due south is ideal, east and west elevations lose meaningful output, and one mature maple on the south side can cost more production than a smaller array would have made.

Step three: the electrical work and the ESA. Almost all electrical work in Ontario must be reported to the Electrical Safety Authority through a notification of work filed before the work begins, and if you hire someone to do it, by law it must be a Licensed Electrical Contractor (Electrical Safety Authority, Notifications and inspections). A building permit is a separate thing from an electrical notification and you may need both. Ontario's alert on photovoltaic systems notes that small amounts of sunlight can produce a voltage potential capable of causing electrocution or arc-flash injury (Ontario, Alert: photovoltaic systems). A panel is live in daylight whatever is switched off.

Step four: the connection. Hydro Ottawa treats residential solar as micro-generation at 12 kW AC or less. You submit a service request indicating net metering capability, and the utility returns a service layout with responsibilities and a quotation, normally within 15 days and up to 60 for a complex project. Layouts are valid 90 days and payment comes before work. Nothing is energized until the preparatory work is done and the Electrical Safety Authority Connection Authorization has been received (Hydro Ottawa, DER connection process).

How long it takes. Two to four days on the roof for a typical 8 to 12 kW array, and three to six months from signed contract to energization. The variable parts are the engineer's schedule, the permit review and the distributor's queue. Anyone promising four weeks end to end is describing the roof work and leaving out the rest.

What it costs in Ottawa in 2026. No public authority publishes installed solar pricing here, so these are indicative ranges rather than sourced figures. Installed cost commonly lands between $2.40 and $3.50 per watt before any rebate, putting a 6 kW array at roughly $14,000 to $21,000 and a 10 kW array at $24,000 to $35,000. What moves it: roof pitch and access, how many planes the array is split across, whether the electrical panel needs upgrading, microinverters against a string inverter, and the engineer's fee. Ask for the engineer's fee and the permit fee as separate lines.

What makes an Ottawa roof different. Snow, and the geometry that follows from it. Panels are more efficient cold, so clear winter days produce well, and then whole weeks go to snow cover. A steep array sheds snow. A near-flat one holds it. Panels also interrupt snow sliding off a slope and can create drifts and ice dams where there were none, which is one more reason the engineer's review is a requirement rather than a formality. The sun itself is fine: the Canada Energy Regulator puts Ottawa at 6.09 kilowatt hours per square metre, ahead of Toronto at 5.94 (Canada Energy Regulator, Which cities have the highest solar potential in Canada).

Who must be involved, and which credential. Three named credentials, all verifiable. A professional engineer licensed in Ontario, for the design and the field review, required by the City. A Licensed Electrical Contractor, required by law for the electrical work. And the Electrical Safety Authority, which must issue the Connection Authorization before the distributor energizes anything. There is no separate provincial solar installer licence in Ontario, so a company describing itself as a certified solar installer is referring to a manufacturer or industry credential rather than a government one. Ask which, and ask who the engineer is by name.

What to ask before you sign. Who is the engineer, and is the field review included. Are you a Licensed Electrical Contractor. Will you file the ESA notification and obtain the Connection Authorization. Is the building permit in your scope or mine. What annual production have you modelled, and in which software. Do you recommend reroofing first. What is the warranty on panels, inverter, racking and roof penetrations, and who honours each.

One thing to settle before anything else. Under Ontario's current rebate you have to choose between the rebate and a net metering agreement, because the rebate is for load-displacement systems only (Home Renovation Savings, solar and battery storage). That single decision changes the system size, the economics and the connection paperwork, so make it first rather than last.