Is my roof good for solar?

Your roof decides a lot about whether solar makes sense and how much power you'll get. Four things matter most: which way it faces, how much shade it gets, what condition it's in, and how much usable space is left after code setbacks. Let's check each.

Orientation and tilt

In the northern hemisphere, south-facing roofs capture the most sun. But you have more freedom than people think:

• South — best production.
• East or west — often just 10 to 20% less; west can even align better with evening usage.
• North — weakest, usually skipped.

Tilt matters less than direction. Most residential roof pitches (roughly 15 to 40 degrees) work fine, and panels can be arranged to make the most of what you have.

Shading is the real killer

Shade hurts more than most people expect. A tree limb or vent shading even part of the array can drag down production. Note anything that casts shadows during the middle of the day:

• Tall trees to the south, east, or west
• Chimneys, vents, and dormers
• Neighboring buildings

Some shading can be worked around with panel placement and module-level electronics, but heavy midday shade is a genuine dealbreaker. Trimming or removing a problem tree can transform a marginal roof.

Condition and age

Panels last 25+ years, so the roof underneath them should too. If your roof is near the end of its life, replace it first — pulling panels off to reroof later is costly. Also consider:

• Material — asphalt shingle, metal, and tile all support solar with the right mounting.
• Structure — the framing must carry the added weight; older or damaged decking may need reinforcement.

Usable space (it's less than the whole roof)

Not every square foot counts. Fire codes require setbacks around edges and ridges for firefighter access, and vents, skylights, and hips break up the area. Each panel is about 18 sq ft, so:

If space is tight, higher-wattage panels get you more power per square foot. See how many panels to power a house for the count.

Get a professional set of eyes

A good desktop check tells you if solar is worth pursuing, but the final call on structure, mounting, and layout belongs to pros. A licensed electrician or PE must design and connect the system, and an installer will verify your roof carries the load safely. Start by learning to size your system, then explore the guides.

Educational reference, reviewed 2026-07. A design aid, not a substitute for a licensed electrician or PE. Confirm the enforced NEC edition and local amendments with your AHJ.