Key takeaways
- Organise the survey by the sheet that needs the data, not by the order you walk the property. Every field maps to a drawing.
- The main service panel label is the single highest-value photo on the survey. Busbar and main breaker ratings decide the interconnection method.
- Capture clear span, not just framing size. Span is what determines whether the structure carries the array.
- Photograph every location you’ll show on the site plan. Equipment drawn where it won’t be installed is the most common correction there is.
- An aerial report covers roof geometry well. It covers none of the electrical, structural or siting data.
What should a solar site survey capture?
A solar site survey should capture everything the plan set has to prove: the electrical service and its capacity, the existing framing and its span, roof geometry and obstructions, shading, and the physical location of every piece of equipment. Organise the capture by drawing sheet, because that’s how the gaps become visible before you leave the property.
Surveys fail in a predictable way. The tech walks the site, gets good roof photos, and comes back missing the one number the drafter needs to size the interconnection. Structuring the checklist by sheet fixes that, because a blank field is visibly attached to a drawing that can’t be finished.
Which sheet needs what
| Plan sheet | What the survey has to supply | Most common miss |
|---|---|---|
| Site plan | Property lines, building footprint, equipment locations, access dimensions | Equipment shown where it won’t be installed |
| Roof plan | Plane dimensions, pitch, azimuth, obstruction positions, ridges and valleys | Only the array area measured, not the whole plane |
| Structural | Framing size, spacing, clear span, deck, roofing layers, condition | Span omitted — size captured alone is unusable |
| Single line diagram | Busbar rating, main breaker rating, available spaces, conductor entry | Panel label never photographed |
| Labels & placards | Equipment locations and service disconnect position | Treated as a drafting detail rather than survey data |
| Production model | Obstruction heights and distances, tree ownership | Shade data estimated rather than measured |
Knowing what belongs in a plan set is what makes this table usable. Every row on it exists because a plan checker will look for it — and because solar plan sets can’t assert something the survey never established.
The electrical service — the highest-value five minutes
Photograph the main service panel label, the panel interior with the deadfront off, the meter, and the service entrance. From those four images a drafter should be able to read the busbar rating, the main breaker rating, the available spaces, and the conductor entry.
The busbar and main breaker ratings decide everything downstream. Under NFPA’s NFPA 70, the National Electrical Code, the busbar allowance at NEC 2023 705.12(B)(3) caps what you can backfeed into an existing panel: main breaker plus backfeed breaker can’t exceed 120% of the busbar rating.
On a 200 A busbar with a 200 A main, that leaves 40 A of headroom — enough for a 7.6 kW inverter at exactly the limit and nothing more. If the survey doesn’t capture the busbar rating, the drafter either guesses or calls you back. Both cost a day.
Capture as well:
- Available breaker spaces and their positions
- Whether the main breaker sits at the top or bottom of the bus
- Panel manufacturer and model
- Any existing subpanels and what feeds them
- Loads the customer plans to add later — a battery, an EV charger, a heat pump
That last one isn’t for this permit. It’s for whether the panel you’re about to fill is the panel they’ll need in two years, and it’s a conversation worth having while you’re standing in front of it.
The structure — span, not just size
Record rafter or truss size, on-center spacing, clear span, roof deck material and thickness, the number of existing roofing layers, and the condition of the framing. Size alone is not enough — span is what governs.
“2×6 at 24 inches” tells a plan checker nothing without the span. A 2×6 spanning eight feet and a 2×6 spanning fourteen feet are different structures, and only one takes an array without reinforcement.
Photograph the attic or underside wherever you can reach it, and measure rather than estimate. Note anything that changes the load path: a previous re-roof that added a layer, sistered rafters, visible sag, water damage, or a truss configuration that isn’t standard.
This is also where the PE stamp question gets answered. Marginal framing, unusual spans, or high wind and snow exposure push a project toward a stamped structural review — and you want to know that during the sale rather than at submittal.
Roof geometry and obstructions
Dimension every roof plane you might use: length, width, pitch, azimuth, and the position of every obstruction — vents, stacks, skylights, chimneys, HVAC curbs, and the ridges, hips and valleys that bound the plane.
The City of San Diego’s Information Bulletin 301, a representative residential PV submittal checklist, requires a roof plan showing slopes, panel placement relative to ridges, hips and valleys, and existing roof equipment. You can’t draw that from a satellite image and a hunch.
Fire setbacks and access pathways are dimensioned items on the same sheet, and they vary by jurisdiction more than almost anything else in a residential submittal. Capture enough of the roof to lay them out, not just the area you intend to fill. A survey that measures only the array footprint forces the drafter to invent the boundary conditions.
Shading
Record obstruction height and horizontal distance for anything that could shade the array — trees, neighbouring structures, and the building’s own upper roof planes and chimneys.
Shade data drives the production model, and the production model drives what you sold. Accurate shade and production modelling depends entirely on what the survey captured; a model built from bad obstruction data produces a number the system won’t hit, and that becomes a customer problem in year one.
Note whether trees are on the customer’s property or a neighbour’s. It changes what can be trimmed, and it changes what you can promise.
Equipment siting — photograph where it’s going
Walk the actual mounting locations for the inverter, AC disconnect, rapid shutdown initiator, any energy storage, and the conduit runs. Photograph each one and note the clearances.
This is the section that prevents the most common correction in the business. A plan showing the AC disconnect on the south wall when it gets installed by the meter on the east wall fails inspection — even though the as-built location was better. The drawing is the agreement.
Decide the locations on site, with the crew’s input, and record them. Note working space in front of electrical equipment, the distance from inverter to meter, and whether the conduit run is interior, exterior, or through conditioned space.
Storage and future loads
If storage is in scope — or might be later — the survey needs more: available wall or floor space with clearances, ambient temperature conditions, egress paths, and the distance from the storage location to the service equipment.
Batteries carry their own siting and clearance requirements, and retrofitting them into a survey done for PV alone usually means a second visit. If the customer has mentioned storage even speculatively, capture the space while you’re there. It costs five minutes now and a truck roll later.
What an aerial report covers — and what it doesn’t
An aerial measurement report handles roof geometry well and speeds turnaround considerably. It covers none of the electrical service, none of the framing, and none of the equipment siting.
Supplying a Roof Order or EagleView XML with a Fast Roof order brings turnaround to a single business day. That’s a real gain, and it’s the right tool for plane dimensions, pitch and azimuth.
What it cannot tell you is the busbar rating, the rafter span, the roof’s condition underneath the shingles, or where the crew can actually mount the inverter. Treating an aerial report as a substitute for the site visit is how a plan set ends up built on assumptions.
The drafter can only draw what the survey captured. Every correction that arrives three weeks later started as a blank field somebody walked past.
The five most common survey misses
- The panel label photo — taken at an angle, out of focus, or skipped entirely because the deadfront was awkward to remove
- Clear span — framing size recorded, span estimated or omitted
- The whole roof plane — only the array area dimensioned, leaving setbacks and pathways undefined
- Equipment locations — assumed at the desk rather than decided on site
- Obstruction heights — distances measured, heights guessed
Most of the common drafting errors that draw corrections are survey gaps wearing a drafting costume. The fix is upstream of the drafter every time.
How to hand it off
Send the survey as one package with the photos named or annotated by what they show. A folder of forty unlabelled images is a survey the drafter has to interpret.
Group by sheet: electrical photos together, structural together, roof and siting together. Flag anything unusual in a short note rather than hoping it’s visible in a picture — a sistered rafter, a subpanel of unknown origin, a neighbour’s tree that’s coming down next spring.
Standardised permitting raises the stakes on completeness. The U.S. Department of Energy describes SolarAPP+ as automating review for residential systems meeting a defined compliance envelope, and automated checks are unforgiving about missing or inconsistent inputs in a way a human plan checker sometimes isn’t.
Running a pre-submittal check catches the gaps, but catching them at the survey is cheaper — and it’s one of the 12 factors for solar project design success that separates shops that scale from shops that firefight. The same discipline is what judging plan set quality rests on.
The one-page version
Before the tech leaves the site, they should have:
- Main panel label photo, panel interior photo, meter photo, service entrance photo
- Busbar rating, main breaker rating, available spaces, main breaker position
- Rafter or truss size, spacing, clear span, deck material, roofing layers, framing condition
- Every roof plane dimensioned with pitch and azimuth
- Every obstruction located, with heights for anything that shades
- Marked locations for inverter, disconnects, rapid shutdown, storage and conduit
- Storage space and clearances, if storage is in scope or possible
- Wide shots of every elevation, and a photo of the address
If any line is blank, the plan set will either wait or guess. Neither is what you wanted, and both show up later as a permit rejection.
FAQ
What should a solar site survey capture?
The electrical service and its capacity, existing framing size and clear span, roof plane dimensions with pitch and azimuth, obstruction locations and heights, shading data, and the physical mounting location of every piece of equipment. Organise the capture by which plan sheet needs it.
Why is the main panel photo so important?
Because the busbar and main breaker ratings determine the interconnection method. NEC 2023 705.12(B)(3) caps the combined main and backfeed breaker at 120% of the busbar rating, and without those two numbers a drafter can’t size the interconnection.
What structural information does the survey need?
Rafter or truss size, on-center spacing, clear span, roof deck material, number of existing roofing layers, and the condition of the framing. Size without span is not usable.
Can you draft from an aerial measurement report instead of a site visit?
An aerial report covers roof geometry well and speeds turnaround — supplying a Roof Order or EagleView XML with a Fast Roof order brings it to one business day. It does not cover the electrical service, framing, or equipment siting, which still require the site.
How long does it take to get solar plan sets?
Avila Solar Drafting delivers standard plan sets in 2–3 business days and Fast Roof plan sets in 1–2 business days, with a one-business-day turnaround when the order includes a Roof Order or EagleView XML. Turnaround starts when complete site data is received.
What happens if the survey is incomplete?
The plan set either waits for the missing data or is drafted on an assumption. Assumptions are what generate corrections, so incomplete surveys tend to surface as AHJ comments weeks later.
Does the survey change if the customer wants a battery?
Yes. Storage adds siting and clearance requirements — available space, ambient conditions, egress paths, and distance to the service equipment. Capture it even if storage is only a possibility.
Send a complete survey, get the plan set back this week
The survey is where the plan set is really made. Everything after it is drafting.
Avila Solar Drafting turns complete survey data into permit-ready plan sets in 2–3 business days — 1–2 for Fast Roof — backed by our guarantee of accurate solar plan sets and six months of free revisions, designed to pass first-time review. PV plan set pricing depends on system size and complexity — current pricing is on the solar plan sets page.
Unusual structure, marginal service, or a jurisdiction you haven’t filed in before? Call 971-410-0655.
