Is My Roof Good for Solar? 7 Things to Check Before You Install

The most common question we hear from homeowners who are thinking about solar: "Is my roof even good enough?" The good news is that the vast majority of roofs — well over 85% — are suitable for solar installation. But knowing what factors matter, and what to look for before scheduling an assessment, helps you go into the process with realistic expectations. Here are the seven things Legacy Energy's engineers check on every roof, and what each one means for your project.

1. Roof Age

The single most important practical consideration is how much useful life remains in your roof. Solar panels have a 25-year performance warranty — and ideally, your roof should last at least as long as your panels.

• Ideal scenario: Roof is 10 years old or newer, or was recently replaced. A solar install can proceed without any roofing work.
• Proceed with caution: Roof is 12–18 years old and in good condition. A thorough inspection is needed to determine if it will last 25 years or if spot repairs are warranted before installation.
• Replace roof first: If your roof has fewer than 5–7 years of life remaining, the right move is to replace it before going solar — or replace it simultaneously. Removing and reinstalling panels to re-roof later costs $1,500–$4,000 and is an avoidable expense.

Legacy Energy can coordinate roof replacement and solar installation as a single project, which simplifies logistics and often saves on combined labor costs. If your roof is nearing end of life, ask your consultant about our roofing coordination service.

2. Roof Angle (Pitch)

The angle of your roof affects how much sunlight your panels receive and at what angle — which directly influences annual energy production.

• Ideal pitch: 15–40 degrees — This range maximizes direct solar exposure for most US latitudes. Most standard American residential roofs fall in this range.
• Flat roofs (0–10 degrees): Very common on commercial buildings and some residential homes. Work excellently for solar using tilted racking systems that angle panels at the optimal 15–30 degree pitch. Ballasted (non-penetrating) mounting is an option on many flat roofs.
• Very steep roofs (45+ degrees): Can support solar but produce slightly less annual energy than optimal-pitch roofs. Installation is also more complex and may carry a modest labor premium.

3. Roof Orientation

Which direction your roof faces — its "azimuth" — is a key production variable. In the Northern Hemisphere, the sun travels across the southern sky, which means:

• South-facing: Optimal orientation. Produces 15–25% more energy annually than east or west-facing roofs. If you have south-facing roof space, this is where your panels should go.
• East or West-facing: Fully viable. West-facing panels actually carry a slight advantage in states with time-of-use electricity pricing, because they produce more power in the afternoon when rates are highest. Production is roughly 15–20% lower than south-facing but payback periods are still excellent.
• North-facing: Not recommended as a primary installation orientation. North-facing panels receive significantly less direct sunlight and produce substantially less energy. Legacy Energy will identify south, east, or west-facing sections of your roof and design around them.

4. Shading

Shading is the factor that most often surprises homeowners — because even modest shading can significantly reduce system output. Legacy Energy uses professional-grade shade analysis software (including aerial imagery and solar irradiance modeling) during every site assessment to quantify shading impact precisely.

• Trees: Even partial tree shading — a branch covering one panel for two hours per day — can reduce whole-system output by 10–20% without panel-level power electronics. With microinverters or power optimizers, shading impact is isolated to affected panels only.
• Chimneys and dormers: Cast shadows that move across the roof throughout the day. Our shade analysis software maps exactly which panels are affected and when.
• Neighboring buildings: Becoming more common in urban and suburban infill areas. We model shadow paths across all seasons, including the winter solstice when shadows are longest.

If shading is significant but unavoidable, microinverter technology (Enphase) or DC optimizers (SolarEdge) can reduce the performance penalty substantially by ensuring each panel operates independently.

5. Roof Material

Solar panels can be installed on virtually every common roofing material, though some are easier and less expensive than others:

• Asphalt shingle: The easiest and least expensive to work with. Standard flashing and lag bolt mounts create a simple, watertight penetration. The vast majority of US residential roofs.
• Metal standing seam: Excellent for solar. Clamp-on mounting systems attach directly to the seam without any penetrations, meaning zero risk of leaks. Often the best option available.
• Clay or concrete tile: Common in Arizona, California, and the Southwest. Requires specialized tile hooks that integrate beneath the tile surface. Works well, but installation takes longer and costs slightly more — typically $500–$1,500 more than asphalt.
• Flat membrane (TPO, EPDM, modified bitumen): Common on commercial roofs. Requires either ballasted (weighted) mounting or penetrating anchors with flashing kits. Both methods work well when installed correctly.
• Wood shake / cedar shingle: Requires careful assessment. Older wood shake roofs may need partial replacement in panel mounting areas before installation can proceed safely.

6. Structural Integrity

Solar panels add weight to your roof structure — typically 3–4 pounds per square foot of panel coverage. For a standard 8 kW system covering approximately 400–450 square feet of roof area, this represents about 1,400–1,800 pounds of additional load.

The good news: the vast majority of homes built to standard residential construction codes easily handle this additional load without any structural modifications. However, Legacy Energy's engineers assess structural capacity on every project. We review available building documentation and, on older homes or homes with visible structural concerns, may recommend a licensed structural engineer inspection before installation proceeds.

7. HOA Rules

Homeowner associations sometimes have rules regarding solar panels — requiring approval, specifying placement, or mandating certain aesthetics. Here's what you need to know:

• Most states have solar access laws that limit an HOA's ability to prohibit solar outright. Colorado, Arizona, California, Texas, Florida, and most other major solar states have laws preventing HOAs from banning solar systems that would otherwise qualify for a permit.
• HOAs can still require approval and may have guidelines around panel placement or aesthetics (all-black panels, for example). These are generally manageable.
• Legacy Energy's team handles HOA approval processes for you — preparing the documentation, architectural review requests, and any required specifications. We've navigated hundreds of HOA applications and know what works.

What If My Roof Doesn't Qualify?

If your roof has significant issues — whether structural, due to age, orientation, or shading — you still have options for going solar:

• Ground-mount system: Panels installed on a freestanding structure in your yard. Full orientation and tilt control, no roof concerns. Best for properties with adequate yard space.
• Carport or pergola mount: Panels mounted over a driveway carport or backyard pergola, creating a functional shaded structure while generating power. Popular in Arizona and other hot climates.
• Community solar subscription: If on-site solar isn't feasible at all, community solar programs allow you to subscribe to a portion of a remote solar installation and receive bill credits. Available in Colorado through Xcel Energy and several community solar developers.