Should you replace your roof before getting solar? The math on a typical house

Solar panels last 25 years or more. Most asphalt shingle roofs do not last that long, and replacing a roof under panels means paying to take the panels off and put them back. So the first solar question is often a roof question.

When the roof should go first

• The roof is past its middle age — roughly 10–15 years on many shingle roofs.
• It has had leaks, missing shingles or hail damage.
• The solar installer will not say in writing that the roof will outlast the panels.

If the roof is young and sound, panels can go on now; ask the installer how they flash every mount.

What the roof costs

On our pricing engine, a typical 1,800 sq ft house at 6/12 pitch, reroofed in architectural shingles with one layer torn off, is $17,807 ($16,561–$19,054). Standing-Seam Metal — which outlasts any panel — is $36,135. Price your own roof from satellite.

For comparison, a solar system on the same house — about 9 kW of standard panels — prices at about $23,385 on our engine before incentives, around $2.60 per watt. Replacing an ageing roof first adds to that — but costs less than paying to remove and reinstall the panels halfway through their life, plus a roof job anyway.

Doing both together

1. Get the roof quote and the solar quote at the same time.
2. Agree who installs and flashes the panel mounts, and who warrants the roof under them.
3. Schedule the roof first, then panels within weeks, so the roof warranty and the mounts are documented together.

Common questions

Should I replace my roof before installing solar?

If it has less than about 10–15 years left, usually yes.

How old can a roof be for solar?

No fixed age; past the middle of its life, replace first, and get the installer's view in writing.

Can I do a new roof and solar at the same time?

Yes — about $17,807 for the roof on a typical house; coordinate the mounts and warranties.