An installer reuses a roof template for a backyard array. The plan checker opens the set and finds a site plan, a single-line diagram and a label sheet. There is no foundation detail, no trench section and no proof that the array sits outside the yard setbacks. The correction notice writes itself.
A ground mount solar permit is a structural and site permit as much as an electrical one. Footings, trench routes, zoning setbacks and extra inspections all enter the submittal. This guide lists the added sheets and the questions to put to the AHJ before drawing starts.
Quick answer. A ground mount solar permit adds a foundation sheet, structural calculations, a trench detail and a dimensioned site plan to the usual electrical set. Foundation inputs are soil, frost depth, wind and snow, all set by the adopted code and the AHJ. NEC 2023 Table 300.5 sets minimum cover. Setbacks are zoning rules. Footing and trench inspections happen before concrete and backfill.
This guide is written for the installer operations manager or permit coordinator. The team already ships roof sets and now has a ground-mount job in the queue. It covers only what changes off the roof, and it sits in the solar permit design resource hub. For the general submission process, read how to submit a solar permit to an AHJ and the solar permit package checklist. For layout, row spacing and foundation type selection, see the ground mount solar design guide.
What a ground mount solar permit adds to a roof set
A ground mount is a small structure plus site work. Published checklists treat it that way. A City of Willow Park, Texas solar permit application checklist marks a rooftop system as needing an electrical permit. It marks a ground mount as needing building and electrical permits. Hillsborough County, Florida routes a ground mount through a Residential Miscellaneous permit, according to its solar photovoltaic system checklist (page last modified January 10, 2025). Jerome County, Idaho states on its ground mounted solar panel permit application that zoning must be approved before the application moves to the building department.
So the first question is not what to draw. It is how many permits apply and in what order.
The table compares a typical roof set with a ground-mount set. The right column cites the published checklist that asks for each item.
| Sheet | Roof set | Ground-mount set | Published AHJ source |
|---|---|---|---|
| Site plan | Array shown on the roof, light site context | Dimensioned property lines, setbacks, easements, existing structures, well and septic, trench route | Fayette County GA, Nevada County CA, Jerome County ID |
| Array plan | Roof plan with fire pathways and ridge setbacks | Array layout with height and distance to every property line | Hillsborough County FL, Lake County CO |
| Attachment or foundation | Flashing and attachment detail | Foundation plan and detail: pier or footing type, size, embedment, frost depth | Fayette County GA, Storey County NV |
| Structural basis | Framing letter or span table | Calculations covering wind, snow and soil, sealed where the AHJ requires it | Hillsborough County FL, Jerome County ID, Nevada County CA |
| Racking documents | Cut sheets | Manufacturer installation specifications that include footings, piers and framing | Storey County NV |
| Single-line diagram | Required | Required, with conduit and conductor schedule from array to point of connection | Fayette County GA |
| Trench and conduit detail | Not applicable | Section view with raceway type, cover and backfill notes | San Luis Obispo County CA, Lake County CO |
| Agency letters | Rare | Environmental Health, fire department or HOA approvals before intake | Fayette County GA, Jerome County ID, Lake County CO |
Three sheets are new: the foundation sheet, the trench sheet and the dimensioned site plan. Everything else is a roof sheet with different content. If your team has no templates for those three, the US solar permit design service covers them as part of an AHJ-ready permit plan set.
What published AHJ checklists ask for on a ground mount
Eight real documents show how far requirements drift between jurisdictions. These are snapshots of published checklists, not promises about how any reviewer will act. Each one names its own code cycle, and several are old.
| AHJ and document | Date or code cycle shown | Ground-mount items |
|---|---|---|
| Hillsborough County, FL | Page modified Jan 10, 2025; “current Florida Building Code” | Digitally signed and sealed engineered drawings; panels may not project into the required front yard; 14 ft maximum height in residential districts; geotechnical report may be required in coastal high hazard, coastal A or muck soil areas |
| Fayette County, GA | Revised 06/14/22 | Environmental Health approval and a site plan with distances to property lines before intake; structural calculations and plans for wind design covering footings, framing and height |
| Lake County, CO | Zoning standard revised Dec 17, 2013 | Site plan shows utility trenching; array outside minimum setbacks and easements; 25 ft maximum height; system sized at no more than 120% of site generation needs; footing inspection listed |
| Nevada County, CA | Effective Jan 1, 2020; 2019 California codes | Site plan shows setbacks and new underground utilities; wet-stamped structural components at 50 lb snow load or above or when snow data is missing; 10 ft brush-free area |
| Storey County, NV | 2018 IRC and 2017 NEC named | Published wind, snow, seismic and 24 in frost criteria; plot walk with array staked; footing inspection for piers |
| Jerome County, ID | 2018 IBC and IRC listed as adopted | Additional structural engineering item; agency letters; well, septic, drain field, canal and easement locations on the site plan |
| Pierce County, WA | Revised 3/26/2024; 2021 codes | General residential design criteria: presumptive soil bearing, frost depth, ground snow rules |
| San Luis Obispo County, CA | BLD-2007, 09/15/2023 | Trench inspection after conduit and before backfill; footing inspection before concrete |
Two lessons come out of the table. Requirements are local, and a single county can attach three or four conditions that a neighbor does not. And the code cycles run from the 2017 NEC to 2021 codes, so a value copied from one county is rarely safe in another. Treat each document as a prompt for your own AHJ call, not as a template.
Foundation design inputs: soil, frost depth, wind and snow
The foundation sheet is only as good as its four inputs. Each comes from a different record, and the AHJ often publishes the answer.
| Input | Where it comes from | What goes on the sheet | Published examples |
|---|---|---|---|
| Soil | Geotechnical report, or a presumptive value the AHJ accepts | Bearing assumption and the report reference | Jerome County ID and Pierce County WA both assume 1,500 psf unless a soils investigation says otherwise |
| Frost depth | AHJ design criteria or adopted local rule | Frost depth and the embedment that clears it | Storey County NV 24 in; Jerome County ID 24 in; Pierce County WA 12 in in low-land areas |
| Wind | Adopted code and ASCE 7 edition, plus AHJ basic wind speed and exposure | Basic wind speed, exposure, risk category, method used | Storey County NV 110 mph; Jerome County ID 115 mph, Exposure C; Pierce County WA 110 mph ultimate, Exposure B assumed |
| Snow | Ground snow load from the adopted standard or AHJ table | Ground snow load and any elevation adjustment | Jerome County ID 30 psf; Pierce County WA 30 psf IRC minimum; Storey County NV 70 to 90 psf by elevation |
The same four fields swing widely across these documents. Snow runs from 30 psf to 90 psf. Frost depth runs from 12 in to 24 in. That spread is why a foundation sheet built for one county cannot move to the next without a fresh look. The wind and snow load criteria by state guide shows how to build the load basis from adoption records and hazard outputs.
Soil and the geotechnical question
Presumptive bearing values are written for vertical bearing. Ask the engineer whether pier uplift and lateral capacity need site data, because those usually govern a ground mount. The solar pile foundation design guide explains SPT N-value, pull-out testing and embedment. Pierce County states that its 1,500 psf assumption applies “unless a soils report from a licensed geotechnical engineer is provided.” Hillsborough County adds a trigger. A soils and foundation analysis may be required in coastal high hazard, coastal A and muck-soil areas.
Frost depth and where it is set
Frost depth is local. The model codes tell the designer to protect foundations from frost, and each state or county fills in the depth. Minnesota’s amended IBC 1809.5, published in Minnesota Rules 1305.1809 in 2015, lists three routes. A foundation extends below the frost line in state rules, is built to ASCE 32, or bears on solid rock. Storey County notes that ground-mount piers will probably run deeper than its 24 in minimum. That is a fair prompt to ask about every shallow element too, such as equipment pads and ballast footings.
Wind and ASCE 7-22 section 29.4.5
ASCE 7-22 added wind provisions for ground-mounted fixed-tilt solar panel systems. The International Code Council’s “Demystifying Loads for Building Officials” training (2024 IBC and ASCE 7-22) lists new provisions in section 29.4.5. It also lists the geometry limits under 29.4.5.1:
- Panel chord length between 6 ft and 14 ft.
- Shortest array row at least 7 chord lengths long.
- Panel angle to the ground between 0 and 60 degrees.
- Mean panel height between 0.5 and 0.8 of the chord length.
- Row spacing such that chord length divided by spacing falls between 0.2 and 0.6.
- Gap between adjacent panels under 0.014 of the chord length.
- Open area within a row under 0.25 of the chord length, and open transverse distance between rows under twice the row spacing.
An array outside any limit cannot use that section as written. Ask the structural engineer to state on the calculation which method was used and why it applies.
Edition matters just as much. The ICC material ties the 2024 IBC to ASCE 7-22. The AHJ documents above name the 2017 NEC, the 2018 codes and the 2021 codes. A jurisdiction still on an older cycle may not reference section 29.4.5 at all. Check the adopted edition first, then use the ASCE 7-22 glossary entry for adoption background. The ASCE wind load guide covers the calculation steps.
Illustrative design-criteria block
Put one criteria block on the foundation sheet so the reviewer sees the inputs in one place. The example below copies the values Jerome County, Idaho publishes on its ground-mount form. It is illustrative. Do not reuse these values at another site.
| Field | Illustrative entry (Jerome County ID form) |
|---|---|
| Adopted codes listed | 2018 IBC, 2018 IRC |
| Basic wind speed and exposure | 115 mph, Exposure C |
| Ground snow load | 30 psf |
| Seismic design category | C |
| Presumed soil bearing | 1,500 psf without soils investigation |
| Frost depth | 24 in |
| Foundation element | To be selected and sized by the responsible engineer |
Trenching and conductor burial depth under NEC 2023
Underground conductors from the array to the point of connection fall under NEC 300.5. This section uses the NEC 2023 edition (NFPA 70-2023). NFPA publishes the code text behind a login. The table below therefore follows the copy reproduced in the North Carolina Office of State Fire Marshal’s compact copy of the 2023 state electrical code amendments. North Carolina adopted the 2023 NEC effective January 1, 2025. Its Item 17 amends the heading of Column 4 only, and the rows below are Columns 1 to 3 as that document prints them. Confirm the table against your AHJ’s adopted copy.
Table 300.5, 0 to 1000 volts, minimum cover in inches:
| Location | Column 1: direct burial cable or conductors | Column 2: rigid metal or intermediate metal conduit | Column 3: nonmetallic raceways listed for direct burial, without concrete encasement |
|---|---|---|---|
| All locations not specified below | 24 | 6 | 18 |
| In trench below 2 in. thick concrete | 18 | 6 | 12 |
| Under 4 in. exterior concrete slab, no vehicular traffic, slab extending 6 in. beyond | 18 | 4 | 4 |
| One- and two-family dwelling driveways and outdoor parking, dwelling use only | 18 | 18 | 18 |
| Under streets, highways, roads, alleys, driveways and parking lots | 24 | 24 | 24 |
Column 4 covers residential branch circuits with GFCI protection. Column 5 covers low-voltage irrigation and lighting circuits. Column 4 is written for branch circuits, so ask the AHJ before relying on it for DC array conductors. North Carolina amended that column heading to 250 volts and 50 amperes, which shows that states change this table.
The edition changes the answer. The 2023 NEC added electrical metallic tubing to Column 3. Table 300.5 note 6 points to 358.10 for corrosion protection. This comes from the Steel Tube Institute’s 2023 NEC changes summary (a trade association, not the code body). Storey County’s handout names the 2017 NEC. Willow Park’s checklist says Texas adopts each new NEC on September 1 of the year it is published. Name the edition on the sheet and confirm which one the AHJ enforces.
For conductor type in buried circuits, confirm the wiring-method rules in NEC 690 for the adopted edition. Size the conductors and check conduit fill separately. The conduit fill glossary entry shows how.
Illustrative trench callout
A single trench often crosses several surfaces. The table below uses the NEC 2023 rows above. The assumptions: the owner’s driveway serves only the dwelling, a 4 in. exterior slab carries no vehicles, the trench crosses one public alley, and the AHJ has not amended Columns 1 to 3. The example is illustrative.
| Trench segment | Nonmetallic raceway (Column 3), in. | Rigid metal conduit (Column 2), in. |
|---|---|---|
| Open yard | 18 | 6 |
| Under owner’s driveway | 18 | 18 |
| Under 4 in. exterior slab | 4 | 4 |
| Under public alley | 24 | 24 |
Metal conduit saves depth only in open ground. Under the driveway and alley the two columns match. The trench sheet therefore needs a cover value per segment, not one number for the whole run. State cover as the depth from the top of the raceway to finished grade, so the drawing and the field crew use the same reference.
Other items belong on the trench sheet. Lake County asks for utility trenching on the site plan. Nevada County asks for new underground utilities on the site plan. Fayette County lists 811 on its guide, which reminds crews to locate existing utilities before digging.
Setbacks and zoning
Three different rules get called “setbacks” on a ground mount. Mixing them is a common reason for a correction notice.
Zoning setbacks and height. These are property-line and height rules. Hillsborough County bars ground-mounted panels from the required front yard, with an exception for lots that have two front yards. It also caps height at 14 ft in residential districts. Lake County bars a ground-mounted system from the minimum setbacks of its zoning district. It must sit outside any easements, and height is capped at 25 ft.
Site constraints. Fayette County requires Environmental Health approval for a ground mount before it accepts the application. Jerome County asks for the well, septic and drain field, canals and ditches and easements on the site plan. A solar array placed over a septic field is a plan-check finding that no code table can fix.
Fire clearance. Roof fire pathways and ridge setbacks do not apply on the ground. A different fire rule does. The Willow Park checklist reproduces 2012 IFC section 605.11.3.3.4. It says setback requirements do not apply to ground-mounted free-standing arrays. It requires a clear, brush-free area of 10 ft around them. Nevada County’s checklist, which cites the 2019 California codes, also asks for a 10 ft brush-free area. The 2012 IFC is an old edition, so confirm the fire code your AHJ enforces. The fire setback glossary entry covers the roof version of the rule.
Ask how the AHJ measures height. A tilted array peaks at one edge. A reviewer who measures that edge reads a different number than one who reads the mounting height.
Inspection points for a ground mount
A roof job usually has a rough and a final. A ground mount adds inspections that happen before the work is buried. The table orders them as the published checklists do.
| Stage | What the inspector sees | Published source |
|---|---|---|
| Plot walk or siting | Array location staked on the ground | Storey County NV; Jerome County ID form lists a siting line |
| Footing or hole | Open excavation or driven pier before concrete is placed | San Luis Obispo County CA; Storey County NV; Lake County CO |
| Trench | Conduit installed and uncovered before backfill | San Luis Obispo County CA |
| Rough electrical | Wiring methods before cover | Storey County NV; Lake County CO |
| Final | Completed system, labels, disconnects | All of the above |
Note the Storey County wording. It lists a footing inspection “for piers on ground mount system”, so a driven pier with no concrete can still draw a footing inspection. Do not assume a driven pier skips the stage.
Fayette County prints a warning that matters here. Any work concealed before the necessary inspection is approved requires an engineer’s evaluation sign-off or must be properly exposed for the inspection. A crew that backfills early turns a one-hour inspection into an engineering letter or a re-dig.
Notice rules also differ. Lake County requires 24 hours of notice. San Luis Obispo County asks the contractor to call one day ahead. Jerome County sets an 8:30 AM cutoff for same-day scheduling. Build the crew schedule so concrete and backfill wait for the inspector, not the other way around.
Permits that sit outside the plan set
Some approvals are not sheets at all. Look for them on the first AHJ call.
- Zoning permit. Jerome County needs it approved first.
- Health or septic approval. Fayette County needs it before intake.
- Fire department letter. Jerome County lists one where the project sits more than 150 ft from the main road.
- Homeowner association permission. Lake County’s checklist says an active HOA should provide permission.
- Stormwater coverage. The US Environmental Protection Agency states that construction stormwater discharges need a Clean Water Act permit when a site disturbs one acre or more. Smaller sites count when they belong to a larger plan that will disturb one acre or more. See the EPA construction stormwater page. Most residential ground mounts sit well below that threshold, but a subdivision lot may not.
Engineering review and stamping
Ground-mount structural requirements vary more than roof requirements. Hillsborough County requires signed and sealed drawings by a Florida-licensed design professional. Jerome County lists additional structural engineering as a required item. Nevada County allows general engineered foundation tables below 50 lb snow load if the calculations include snow. It requires wet-stamped components at 50 lb or above, or when snow data is missing. Pierce County requires structural calculations by a Washington-registered engineer above 70 psf ground snow under 2021 IRC section R301.2.3. Willow Park leaves the sealing decision to the building official.
That is five different rules in five places. Stamping requirements are confirmed at quote stage, once the project address and the AHJ’s current position are known. The post on structural PE stamps for solar explains the roof-side logic.
Ten questions to send the AHJ before you draw
Send these in writing and save the reply with the job file. A dated email gives the next reviewer a traceable basis.
- Which permits apply (building, electrical, zoning), and in what order?
- Which editions of the IBC, IRC and NEC are enforced, and does the jurisdiction reference ASCE 7-22?
- Does the AHJ publish design criteria for wind, exposure, ground snow, seismic category and frost depth?
- Is a geotechnical report required, or is a presumptive bearing value accepted?
- Does every ground mount need an engineer’s seal, or only above a height or snow threshold?
- What are the zoning setbacks and the height limit, and where is height measured?
- Are agency letters (health, fire, highway) or HOA approvals needed before intake?
- What clear area does the fire code require around the array?
- What trench cover does the AHJ expect, and is Table 300.5 amended in this state?
- Which inspections apply, in what order, and how much notice is required?
Run the same ten questions on every new county. Over time the answers become a jurisdiction sheet that the permit team reuses, so the next job in the same county starts with fewer lookups.
Where Heaven Designs fits
Heaven Designs is a design and engineering firm, founded in 2020 in Surat, with 50+ engineers (company-stated). It prepares AHJ-ready US permit plan sets through its solar permit design service for US installers. That includes the sheets in this guide. Turnaround is agreed at scoping, and stamping requirements are confirmed at quote stage. Heaven Designs does not install systems or supply hardware.
To compare drawing quality first, request the design sample pack. To start a ground-mount job, send the site address and the AHJ checklist through the contact form. The team replies within 1 business day (company-stated).
FAQ
Does a residential ground mount need a different permit from a roof system?
Often yes. The Willow Park checklist asks for building and electrical permits on a ground mount against an electrical permit alone for a rooftop system. Hillsborough County uses a Residential Miscellaneous permit. Confirm the permit type and order with the AHJ.
How deep must conduit be buried for a ground-mount array?
It depends on the wiring method and the surface above it. Under NEC 2023 Table 300.5, general locations need 24 in for direct burial cable and 6 in for rigid metal or intermediate metal conduit. Nonmetallic raceways listed for direct burial need 18 in. Roads and alleys need 24 in for every method. Confirm your state’s adopted edition and amendments.
Do roof fire setbacks apply to a ground mount?
No, the roof pathway and ridge rules are written for roofs. Ground arrays draw a clear area instead. Willow Park’s 2012 IFC text and Nevada County’s checklist both name 10 ft of brush-free space around the array. Check the fire code edition your AHJ enforces.
Does a ground mount need a soils report?
Not always. Jerome County and Pierce County both publish a 1,500 psf presumptive value for use without a soils investigation. Hillsborough County says a geotechnical analysis may be required in coastal high hazard, coastal A and muck-soil areas. Ask the AHJ and the structural engineer.
Does a ground mount need an engineer’s seal?
The published checklists disagree. Hillsborough County requires sealed drawings, Nevada County sets a snow-load threshold, and Willow Park leaves the decision to the building official. Heaven Designs confirms stamping requirements at quote stage.