Key takeaways
- Permitting, not installation labor, is where most calendar time disappears. NREL puts the average at a week or longer to get approval on a new solar project.
- Where it is available, SolarAPP+ removes that queue entirely. NREL reports more than 160 communities automating permitting with it, cutting at least 5 to 10 business days off the process.
- Revisions almost always trace back to the site survey. Assumed measurements and unrecorded service panel details are the expensive ones.
- Draw to the cycle the AHJ has actually adopted. Oregon enforces the 2023 Oregon Electrical Specialty Code (2023 NEC); the District of Columbia is still on the 2014 NEC.
- Avila Solar Drafting returns plan sets in 2-3 business days standard and 1-2 business days on Fast Roof with complete information, with free revisions for six months.
What actually slows a solar install down?
Not the roof work. On a typical residential job the crew is on site for a day or two; the schedule is set by everything either side of that. Permit review, plan revisions, interconnection approval and inspection scheduling are where weeks go. Every one of those is a document problem, which means every one of them is fixable before anybody climbs a ladder.
That reframing matters because it changes where you spend effort. Shaving an hour off racking installation is a real gain but a small one. Removing a two-week revision cycle from a plan check is a much larger one, and it is available on every job rather than on the good ones.
The rest of this guide works through the four places installers lose the most days, in the order they occur: the site survey, the plan set, the code cycle, and crew scheduling around permit timing. The output of the first three is a single artifact, the solar plan set, which is why so much of the schedule turns on it.
How long does solar permitting take, and why?
Per NREL, it takes on average a week or longer to receive approval on a new solar project in the United States, and that is before any resubmittal. The cause is fragmentation: every jurisdiction in the U.S. has its own process and requirements, so a submittal package that satisfies one AHJ can be incomplete for the next one over.
NREL’s own summary of the problem in its SolarAPP overview describes the typical sequence as waiting for review, waiting for a decision, and restarting if rejected. The restart is the part that hurts. A rejection does not add a day of correction time; it puts you at the back of the queue.
There is a structural fix in some places. SolarAPP+, NREL’s standardized plan review software, automatically checks system designs for safety and code compliance and issues eligible residential permits without human review. NREL reports more than 160 communities automating permitting with it and says it standardizes up to 90 percent of standard system plans. In the NREL summary above, it cuts the permitting process by at least 5 to 10 business days.
Two caveats. SolarAPP+ covers standard residential configurations, so anything unusual still goes to conventional review. And it only accelerates jurisdictions that have adopted it, which is a minority of the country. Check adoption before you promise a homeowner a date.
This is also the cost story. The U.S. Department of Energy classifies permitting, inspection and grid interconnection as soft costs – the non-hardware costs of going solar – alongside customer acquisition and labor, and notes that soft costs represent a growing share of total system cost as hardware prices fall. Time spent in a permit queue is not neutral; it is margin.
If you want the full sequence of what happens between contract and permission to operate, we mapped it in the solar permitting process, stage by stage.
How do you stop the site survey from causing revisions?
Record, do not estimate. Almost every plan set revision we issue traces back to a dimension, an equipment rating or a panel detail that was assumed on site and turned out wrong. A survey that takes twenty minutes longer at the property routinely saves a week later, because it removes the round trip between the drafter, the installer and the AHJ.
The four items that generate the most rework:
- Roof condition and structure. Age, deck type, rafter size and spacing, and any existing damage. A re-roof discovered after the plan set is drawn resets the schedule and sometimes the design.
- Service equipment. Main breaker rating, busbar rating, meter configuration and available breaker spaces, photographed with the panel schedule legible. This is what drives the interconnection method.
- Shading. Measured, not eyeballed, across the year. Where the production number is doing sales work, back it with a production report from Aurora, Helioscope or PVsyst.
- Dimensions and obstructions. Ridge and eave lengths, setbacks, vents, skylights and existing penetrations. Inaccurate roof dimensions remain the single most common cause of a redraw.
The SEIA Installation Best Practices document, produced by SEIA’s Quality Assurance Working Group, makes the same argument from the quality side: consistency in the residential installation process is what makes the outcome predictable. Speed and quality are the same discipline here, not a trade-off.
We keep a field version of this in the solar site survey checklist. Hand it to whoever is going to the property.
What has to be in the plan set before you submit?
A submittal-ready residential plan set carries a site plan, a roof plan with module and racking layout, structural attachment details and calculations, a single-line or three-line electrical diagram, equipment specifications and listings, the placard and labeling schedule, and the applicable code references. Missing any one of them is a completeness rejection rather than a design disagreement.
Completeness is the distinction worth internalizing. Plan checkers are not usually arguing with your engineering. They are looking for a sheet that is absent, a number on the site plan that contradicts a number on the single-line, or a code citation written to an edition their jurisdiction has not adopted. Those are all avoidable before the package leaves your office.
Two references worth keeping open: what is included in a permit-ready plan set for the sheet-by-sheet breakdown, and the pre-submittal checklist for the last pass before you upload. If you want the failure modes rather than the requirements, why solar permits get rejected is written from actual AHJ comments.
Which code cycle does the plan set have to be drawn to?
Whichever one the jurisdiction has adopted, which is not necessarily the newest one published. Adoption is uneven: Oregon enforces the 2023 Oregon Electrical Specialty Code, based on the 2023 National Electrical Code, while the District of Columbia’s construction codes still adopt the 2014 National Electrical Code. Jurisdictions are spread across several NEC editions, so confirm before you draw.
Both of those are verifiable at the source. The Oregon Building Codes Division electrical page gives the 2023 OESC an effective date of October 1, 2023 and flags a 2026 OESC adoption already in development. The DC Department of Buildings construction codes page confirms the 2017 DC Construction Codes, effective May 29, 2020, are based on the 2015 ICC family of model codes and the 2014 NEC.
Structural editions move too, and independently. Oregon’s 2025 Oregon Structural Specialty Code, based on the 2024 International Building Code, has been mandatory since April 1, 2026. A set drawn to the superseded structural edition is a rejection even when the electrical work is perfect.
Three provisions worth naming explicitly on the sheet rather than implying:
- NEC 2023 705.12(B)(3)(2) – the 120 percent busbar allowance for load-side interconnection. The utility overcurrent device rating plus the inverter overcurrent device rating must not exceed 120 percent of the busbar ampacity. Keep it separate from the 125 percent factor applied to continuous inverter output current when sizing conductors and overcurrent protection.
- NEC 2023 690.12 – rapid shutdown. Identify the controlled conductors, the initiation device and where it sits, and put the labeling on the placard schedule.
- NEC 2023 690.8 – circuit sizing and current. Show the calculation rather than the result, so the plan checker does not have to reconstruct it.
For the wider map of which article governs which sheet, see which NEC articles govern a solar plan set. Regional detail lives on our Oregon, Texas and Washington DC plan set pages.
How do regional conditions change the design?
Climate loads and local amendments, mostly. The electrical design travels reasonably well across state lines once you have the right NEC cycle; the structural design does not. Wind, snow and seismic parameters are site-specific inputs, and the attachment schedule has to be calculated from them rather than copied from the last job.
- Pacific Northwest. Snow load east of the Cascades and in the mountains is a different calculation from a Willamette Valley roof. Oregon’s statewide code removes AHJ-to-AHJ technical variation but not submittal format variation.
- Gulf and South Atlantic coasts. Wind is the governing load. Racking, attachment spacing and uplift resistance have to be justified against the site wind speed, not the product datasheet’s best case.
- Snow country and the upper Midwest. Ground snow load plus drift at parapets and adjacent roof planes. Show the load path down to the rafter.
- Northeast. Older housing stock means undersized services, knob-and-tube surprises and framing that does not match any standard span table. Budget for a service upgrade conversation earlier than you would elsewhere.
- Desert Southwest. High ambient temperature drives conductor derating and inverter siting, and cold-morning Voc still sets the string ceiling. Our string sizing walkthrough works both ends of that.
One service note before you scope a job in those regions. Avila does not provide engineering stamps in four jurisdictions: APS and SRP territory in Arizona, the City of Peoria, AZ, the City of Phoenix, AZ, and Los Angeles County (LABD) in California. Everywhere else, PE and SE stamps are available. Ground-mounted arrays follow their own structural path, covered on our ground mount plan sets page.
Does outsourcing the drafting actually make you faster?
It makes the drafting step predictable, which is what turns into speed. An in-house drafter is as fast as their current queue; an outsourced set has a stated turnaround you can schedule against. Avila returns standard plan sets in 2-3 business days and Fast Roof sets in 1-2 business days with complete information, so the date goes into the calendar before the survey is finished.
| Dimension | In-house drafting | Avila drafting |
| Turnaround | Depends on who is free that week | 2-3 business days standard, 1-2 on Fast Roof with complete information |
| Code coverage | Limited to the cycles your team actively tracks | Drawn to the cycle the AHJ has adopted |
| Capacity | Fixed; queues when volume spikes | Flexes with your pipeline |
| Revisions | Your team’s time, at the expense of the next job | Free revisions for six months |
| Stamping | Separate PE engagement to arrange | PE and SE stamps available, outside the four excluded jurisdictions |
Pricing depends on scope and complexity — current figures are on the solar plan sets page. Avila guarantees accurate solar plan sets and every set is designed to pass first-time review, but the AHJ makes the decision and you make the submission – we produce the documents, you file them.
The honest version of the trade-off, including the cases where keeping it in house is the right call, is in outsourced solar design vs in-house.
How do you schedule crews around permit timing?
Sequence off the permit, not off the sales date. Order equipment and hold crew days against the permit issue date rather than the contract date, and keep a second job staged so a slipped approval moves a crew sideways instead of idling it. The installers who stay busy are the ones with something ready to swap in.
- Survey and submit the design request the same week the contract signs. The drafting queue and the permit queue run in series, so starting late costs twice.
- Submit the permit package and the utility interconnection application together, with matching array size, inverter model and panel ratings on both.
- Confirm materials are on site before the crew day, not on it. A missing balance-of-system part stops the whole day.
- Give the crew a set they can read. A plan set that needs a phone call to interpret is a plan set that produces field deviations, and field deviations produce failed inspections.
- Book the inspection as soon as the install date is fixed, and keep the as-built consistent with the approved set.
None of this is glamorous, and all of it compounds. Removing one revision cycle and one idle crew day per job is a bigger annual number than any single process improvement on the roof.
Frequently asked questions
How can I speed up solar permit approvals?
Submit a complete, internally consistent package the first time. Most delays are completeness failures rather than design disagreements: a missing sheet, a dimension on the site plan that contradicts the single-line diagram, or a code citation written to an edition the jurisdiction has not adopted. Confirm the adopted NEC and building code cycles before drawing, match the permit package to the interconnection application, and check whether the jurisdiction accepts SolarAPP+, which NREL says removes 5 to 10 business days where it is available.
What is included in a professional solar plan set?
A submittal-ready residential set includes a site plan, a roof plan with module and racking layout, structural attachment details and calculations, a single-line or three-line electrical diagram, equipment specifications and listings, the placard and labeling schedule, and the code references the jurisdiction expects. The same package serves two audiences: the plan checker who approves it and the crew who builds from it, which is why clarity matters as much as completeness.
How long does a solar plan set take?
Avila returns standard plan sets in 2-3 business days and Fast Roof plan sets in 1-2 business days, in both cases with complete information from the site survey. Pricing depends on system size and complexity — current figures are on the solar plan sets page, and every set includes free revisions for six months. Avila produces the drawings, calculations and details; the installer submits them to the AHJ and the utility.
Does SolarAPP+ make solar permitting faster?
Where a jurisdiction has adopted it, yes. SolarAPP+ is NREL standardized plan review software that automatically checks system designs for safety and code compliance and issues eligible residential permits without manual review. NREL reports more than 160 communities using it, says it standardizes up to 90 percent of standard system plans, and puts the saving at at least 5 to 10 business days. It applies to standard residential configurations only, and unusual designs still go to conventional review.
Which NEC edition should a solar plan set be drawn to?
The edition the jurisdiction has adopted, which is not always the newest published. Oregon enforces the 2023 Oregon Electrical Specialty Code, based on the 2023 National Electrical Code, effective October 1, 2023. The District of Columbia construction codes, effective May 29, 2020, adopt the 2014 National Electrical Code. Jurisdictions are spread across several NEC editions, so confirm the adopted cycle with the AHJ before drawing and cite it on the sheet.
Should a small solar installer outsource drafting?
It depends on volume consistency rather than company size. Outsourcing converts drafting from a queue you manage into a scheduled step with a stated turnaround, which is most valuable when your pipeline is uneven or you are entering unfamiliar jurisdictions. Keeping it in house makes more sense when volume is steady, the jurisdictions are few and well understood, and the designer is already on staff. Many installers run both, outsourcing overflow and unfamiliar territory.
Get the drafting off your critical path
Send us the survey and the equipment list and you get a set drawn to the cycle your AHJ has adopted, with the busbar calculation, the rapid shutdown provisions and the attachment schedule shown on the sheet rather than assumed.
Order a plan set, or call 971-410-0655 to talk through the pipeline first.
