About the 500-Gallon Propane Tank
The 500-gallon propane tank is a standard residential size used for Whole-home heating, most common residential size. It holds approximately 400 gallons of usable propane when filled to the standard 80% capacity level (tanks are never filled beyond 80% to allow for thermal expansion of the liquid).
Understanding the permit requirements before you purchase or lease a 500-gallon tank prevents costly surprises on installation day — including last-minute permit applications, inspection delays, and potential insurance issues if installation proceeds without required permits.
Permit Requirements
Above-Ground Installation
Required in most jurisdictions. Even where no LP tank installation permit is required, a gas piping permit for the supply line from the tank to your home is almost always required. Always verify both permit requirements with your county building department or fire marshal before proceeding.
Underground Installation
Underground 500-gallon tanks always require a permit everywhere in the United States, regardless of county, jurisdiction, or ownership arrangement. Underground installations also require a pre-backfill inspection before the excavation is covered, cathodic corrosion protection, and a vent pipe terminating above grade. Full underground permit guide →
NFPA 58 Setback Requirements
| From This Feature | Min. Distance |
|---|---|
| Building walls | 10 feet (NFPA 58) |
| Windows, doors, openings | 10 feet (NFPA 58) |
| Property line | 10 feet (NFPA 58) |
| Ignition sources (electric meter, AC unit) | 10 feet (NFPA 58) |
| Public road | 10 feet (NFPA 58) |
Use our Setback Calculator to verify your specific site layout. Your local AHJ may require greater distances than NFPA 58 minimums.
How to Apply for a Permit
The permit application process for a 500-gallon residential propane tank involves: determining your jurisdiction's permit requirement, preparing a site plan with measured setback distances, gathering your contractor's license information and the tank's spec sheet, submitting the application to your county building or fire department, and scheduling the required inspection(s) after installation. Step-by-step application guide →
What the Inspector Checks
During the final inspection, the building or fire inspector will verify setback distances with a tape measure, check tank placement and labeling, inspect the pressure regulator and shutoff valve, and verify the gas supply line connections and pressure test results. Complete inspection guide →
Even if your county does not require an LP tank installation permit for a 500-gallon above-ground tank, a gas piping permit for the supply line is almost always required separately. Ask specifically about both permits when you call your building department.
A 500-gallon tank must be installed by a licensed LP gas contractor in virtually all states. If you are leasing the tank from a propane supplier, their installation crew handles the work. If you own the tank outright, you hire a licensed contractor. Always verify the contractor's state LP gas license before work begins.
In most jurisdictions, a standard residential LP gas permit for a 500-gallon above-ground tank takes 1–5 business days for approval. Larger cities with online portals may issue same-day or next-day. Underground installations requiring plan review can take up to 2 weeks. Apply at least 2 weeks before your scheduled installation date.