FindSolar.caBefore any installer runs your address through design software, you can screen your own roof in ten minutes with a maps app and an honest look from the sidewalk. Four things decide roof suitability for solar in Canada: which way it faces, how much clear area it offers, what shades it, and what shape it is in. Here is how to read each one like a designer would.
Orientation: south is best, east-west is fine
A south-facing plane is the ideal, but the gap is smaller than folklore says: southeast and southwest give up only a few percent on planning factors, and a straight east or west roof still delivers about 85% of ideal annual production. East-west pairs also spread production across the day, which suits homes that use power at breakfast and dinner. North-facing planes, at about 62%, are usually left out of designs. Check your roof's compass bearing in any maps app; the production guide shows what each orientation does to annual output.
Area: what actually fits
Plan on roughly 100 square feet of clear roof per kilowatt of panels. A typical 8 kW home system therefore wants about 800 square feet of usable plane, and usable is the operative word: vents, chimneys, skylights, dormers and code setbacks from edges and ridges all subtract. Steep, cut-up roofs with many small faces fit fewer panels than their total area suggests, while a plain gable swallows a big array easily.
Shade: the input worth modelling, not guessing
Shade is where driveway assessments fail. A tree that is clear in March can shade the array all August, a neighbour's spruce grows a metre a year, and a chimney's shadow walks across the roof daily. Designers model this properly with site tools, and you should treat any quote that never assessed shade as incomplete. If trees are borderline, weigh trimming against the production gain; and remember module-level electronics manage shade losses but never recover the sunlight itself.
Condition: the roof under the array
Panels occupy a roof for 25 years or more, so the surface beneath them needs comparable life expectancy; the reroof-first guide gives the decision rule. Structure is rarely an issue for modern trussed roofs carrying a few pounds per square foot of array, but older homes and unusual framing deserve the structural question asked out loud. If your screening passes all four tests, you are ready to invite quotes and judge them from strength; if one fails, better to know before the salespeople arrive.
Questions homeowners ask
Does my roof have to face south for solar to work?
No. South is ideal, but east or west planes still deliver about 85% of ideal annual production on planning factors, and southeast or southwest nearly all of it. East-west designs also spread output across morning and evening, which suits how many households actually use power. Only north-facing planes are usually excluded.
What roof pitch is best for solar in Canada?
Common residential pitches all work; annual production changes only modestly across the typical range. Steeper roofs shed snow faster, which helps winter output, while shallower roofs are easier to work on. Designers optimize what your roof offers rather than chasing a theoretical angle, so pitch is rarely a deciding factor.
How much shade is too much shade for solar?
Enough that no panel placement avoids it for the productive hours of the day, across seasons. That judgment needs a proper shade model, not a glance: shade moves daily and seasonally, and trees grow. Light, managed shade is designable; heavy persistent shade is the one problem equipment cannot fix.
How much clear roof space do I need?
Plan on roughly 100 square feet per kW, so about 800 square feet for a typical 8 kW system. Vents, skylights, dormers and code setbacks from edges all subtract from the gross area. A simple large plane fits more than the same area cut into small faces.
Can I put panels on more than one side of my roof?
Yes, multi-face designs are routine. Each face has its own production profile, which modern inverter architectures handle cleanly, with module-level electronics the usual choice when faces differ a lot. Expect the secondary face to produce at its orientation factor, and let the designer decide whether it earns its place.
Should I cut down trees to improve solar production?
Sometimes trimming pays for itself in production; removal is a bigger call that trades energy against shade comfort, property character and the tree itself, and municipal rules can apply. Model production with and without the tree, then decide with real numbers rather than resentment toward a spruce.