Solar Site Survey Checklist for US Installers (Avoid Costly Mistakes)

The site survey is the quietest step in a solar project and the one that decides everything downstream. A clean survey feeds an accurate design, a permit that clears on the first submission, and an install crew that shows up to a job with no surprises. A sloppy survey feeds change orders, truck rolls, and a customer who starts to doubt the company.

At Wattmonk, the survey is where every design and proposal begins. Our site survey app guides a rep through the capture, and our automation checks the inputs before the engineering team starts work. Along the way, we have seen the same handful of misses turn small jobs into expensive ones. This checklist covers what a complete solar site survey should capture, and the mistakes that cost installers the most.

Why the site survey carries so much weight

A solar design is only as accurate as the field data behind it. Aerial imagery and satellite tools are useful for a first look, but they miss what happens on the ground: the true condition of the main service panel, the size and spacing of rafters in the attic, the shade a neighbor's tree throws at 4 p.m. in December.

When any of that is wrong or missing, the cost does not disappear. It moves downstream, where it is far more expensive to fix. A measurement error caught during the survey costs minutes. The same error caught on install day costs a crew, a truck, and a rescheduled customer.

The solar site survey checklist

1. Property and site overview

• Confirm the address and match it to the correct structure, including the right building on multi-structure lots.
• Capture a clear site map showing the home, the roof, and the location of major equipment.
• Note access points, gate codes, pets, and any obstacle that would slow an install crew.
• Photograph the overall property from the street and from each side of the house.

2. Roof measurement and condition

• Measure every roof plane that could host modules, recording length, width, and usable area.
• Record the azimuth (the compass direction each plane faces) and the tilt or pitch.
• Identify the roof covering, whether asphalt shingle, tile, metal, or flat membrane, since it drives the mounting method.
• Document the roof condition and approximate age. A roof near the end of its life is a conversation to have before install day.
• Capture all obstructions on the roof: vents, chimneys, skylights, satellite dishes, and existing penetrations.
• Note the number of roof layers where visible, because a second layer changes the structural picture.

3. Shading analysis

• Record every shading source, including trees, chimneys, adjacent buildings, and rooflines.
• Capture shading as it changes across the day and across the seasons rather than from a single snapshot.
• Flag obstructions that cannot be removed so the design team can plan module placement and module-level electronics accordingly.

Shading is one of the most common reasons a system underperforms its estimate. Getting it right in the field is far cheaper than explaining a production shortfall a year later.

4. Electrical assessment

• Photograph the main service panel with the cover on and off, showing the busbar rating and the main breaker rating clearly.
• Record the panel manufacturer and the amperage, since the busbar rating drives interconnection options and the well-known 120 percent calculation.
• Document the meter, the main service disconnect, and the utility service entrance.
• Capture the available breaker spaces and the panel labeling.
• Note the location where the new solar equipment and conduit would run.

Electrical data is where many surveys fall short, and it is also where a miss forces a full redesign. A panel that cannot support the system as drawn means either a main panel upgrade or a smaller system, and both change the deal.

5. Attic and structural evaluation

• Access the attic where possible and measure rafter or truss size, spacing, and span.
• Photograph the framing so a structural reviewer can confirm the roof carries the added load.
• Note the roof decking type and any signs of water damage, rot, or prior repair.
• Record insulation and any conditions that affect drilling and mounting.

Structural data protects both the customer and the installer. It is also one of the items reviewers flag most often when it is missing from a permit package.

6. Interconnection and equipment siting

• Identify where the inverter, rapid shutdown equipment, and any battery would sit.
• Confirm wall space, clearances, and a path for conduit.
• Note the distance from the array to the point of interconnection.

The survey mistakes that cost installers the most

Even experienced crews repeat the same errors. The expensive ones include:

• Skipping the attic. Guessing at rafter size to save fifteen minutes on site can trigger a structural redesign and a second visit.
• Bad electrical photos. A blurry panel label or a missing busbar rating forces a callback before the design can even start.
• Single-moment shading. Judging shade from one photo at midday misses the low winter sun that will cut into production.
• Estimating roof geometry. Trusting an aerial measurement instead of confirming azimuth and pitch on site puts every production number at risk.
• Incomplete site context. Missing access notes or the wrong structure on a shared lot sends a crew to a job they cannot finish.

Every one of these is preventable with a disciplined checklist and a quality check before the data leaves the field.

Turning survey data into a design-ready package

Capturing the data is half the job. The other half is handing it off in a form the design team can use without guessing. A survey that lives as a pile of unlabeled photos on someone's phone is nearly as risky as no survey at all, because the designer has to interpret what the rep saw.

A clean handoff includes labeled photos tied to each roof plane, clear electrical shots that show the ratings a designer needs, measurements recorded against a site map, and notes on anything unusual. When the package arrives organized and complete, the design moves straight into drafting. When it arrives as a guessing game, the design team burns time chasing clarifications, and the project slows before it has really started.

How Wattmonk keeps surveys clean

We built our process around removing these misses. The Wattmonk site survey app walks a rep through capturing every detail the engineering team needs, with customized templates so nothing gets skipped in the field. A survey can be completed in minutes, covering roof, shading, electrical, and structural details in one visit. Then our automation reviews the inputs for completeness and flags anything missing before the project moves to design, so a gap gets caught while a rep can still fix it rather than on install day. From there, the same verified survey data auto-feeds our plan sets and sales proposals.

The result for an installer is a survey you can hand to engineering with confidence, a design that reflects the real roof, and a permit package that is less likely to bounce.

Final word

A solar site survey is not paperwork to rush through. It is the foundation the design, the permit, and the install all stand on. Use a complete checklist every time, capture the electrical and structural detail that surveys most often miss, and check the data before it leaves the field.

That discipline is what we deliver at Wattmonk. Accurate field data, checked before it reaches engineering and fed straight into your designs and proposals, so the costly mistakes stay off your schedule and off your budget.

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