The NFPA 58 Setback Framework
Propane tank setback requirements in the United States are based on NFPA 58: Liquefied Petroleum Gas Code, the national standard published by the National Fire Protection Association. Most states and counties have adopted NFPA 58 as their governing standard either directly or by reference through the International Fuel Gas Code.
NFPA 58 setback distances are determined by two factors: tank size (gallons) and the type of feature you are measuring from. The standard addresses setbacks from building walls, from openings in buildings (windows, doors, dryer vents, AC intakes), from property lines, from public roads, and from ignition sources like electric meters and AC compressors.
These are minimum distances. Your local Authority Having Jurisdiction (AHJ) — your county building department, fire marshal, or city planning office — may require greater setbacks than NFPA 58 minimums. Your homeowner's insurance policy may also impose additional clearance requirements. When in doubt, place the tank farther away, not closer.
Complete NFPA 58 Setback Table — All Tank Sizes
| Tank Size | From Building Walls | From Windows / Doors / Openings | From Property Line | From Ignition Sources | From Public Road |
|---|---|---|---|---|---|
| Up to 125 gal | 10 ft | 10 ft | 10 ft | 10 ft | 10 ft |
| 126–250 gal | 10 ft | 10 ft | 10 ft | 10 ft | 10 ft |
| 251–500 gal | 10 ft | 10 ft | 10 ft | 10 ft | 10 ft |
| 501–2,000 gal | 25 ft | 25 ft | 25 ft | 25 ft | 25 ft |
| 2,001–30,000 gal | 50 ft | 50 ft | 50 ft | 50 ft | 50 ft |
All distances are measured from the nearest point of the tank to the nearest point of the feature. For a building wall, measure from the tank's outer shell to the wall surface. For windows and doors, measure to the nearest edge of the opening. For the property line, measure to the legal property boundary. Use a tape measure — inspectors will.
What Counts as an "Ignition Source"?
This is the most commonly misunderstood part of propane tank setback requirements. An ignition source is any device or feature that could ignite propane vapor in the event of a release or slow leak. NFPA 58 requires the same setback from ignition sources as from building openings. Common ignition sources that require clearance:
- Electric meters and electrical panels: The meter base and electrical panel box on the exterior of your home are ignition sources. A 10-foot setback (for tanks under 500 gal) is required from these features.
- Central air conditioning compressor units: Outdoor AC condenser units contain electric motors and contactors that can spark. They require the same setback as building openings.
- Standby generators: Gasoline or natural gas generators are particularly important to consider. If you have a standby generator installed near the house, verify that your proposed tank location maintains the required setback from the generator.
- Dryer exhaust vents: The heat and potential spark from a dryer exhaust vent counts as an ignition source and opening in the building envelope under NFPA 58.
- Pool or spa equipment pads: Heaters, pumps, and electrical equipment in pool equipment enclosures.
- Barbecue grills (permanent or fixed): Fixed outdoor cooking equipment counts. Portable grills that are moved regularly are not typically counted as fixed ignition sources.
Measuring Setbacks on Your Property
Before your installer arrives — or before you apply for a permit — walk your property with a measuring tape and locate the best tank placement area. Here is a practical approach:
1. Identify all setback constraints
Make a rough sketch of your property showing: the house footprint, all exterior openings (windows, doors, vents), the electric meter and AC unit locations, all outbuildings, property lines (use your survey or property tax map), and any wells, septic systems, or water features.
2. Draw the setback zone
For a tank under 500 gallons: the tank center must be placed such that every point of the tank shell is at least 10 feet from all constraints listed above. For a 500-gallon tank (approximately 10 feet long and 37 inches in diameter), this means the tank center needs to be about 15 feet from a wall to clear the 10-foot setback from the nearest tank edge.
3. Use our calculator
Our Setback Calculator handles the geometry for you — enter tank size and installation type, get all required clearance distances.
Three Things Your Local AHJ May Require Beyond NFPA 58
1. Greater setbacks in high-density areas
Many municipalities in suburban or urban settings require greater setbacks than NFPA 58 minimums, particularly where lots are small and neighboring structures are close. It is common to see 15-foot or even 20-foot setback requirements for above-ground residential tanks in suburban jurisdictions that have adopted locally amended versions of the fuel gas code.
2. Setbacks from septic systems
NFPA 58 does not address septic system setbacks, but many county health departments require propane tanks to be set back from septic tanks and drain fields — typically 10–25 feet. This is a separate requirement from the fire code setbacks and is often enforced by the county health department rather than the building department. If your property has a septic system, check with both departments.
3. Vegetative clearance requirements
Some jurisdictions, particularly in the wildland-urban interface (rural areas prone to wildfire), require a defensible space clearance around above-ground propane tanks — typically 10 feet of cleared non-combustible or low-fuel ground cover around the tank. This is distinct from the structural setbacks and is typically enforced by the fire marshal or state forestry agency in fire-prone counties.
Common Setback Violations — And How Inspectors Find Them
These are the most common setback violations found during LP gas installation inspections:
- Tank too close to AC unit: Homeowners and even some installers overlook that the outdoor AC condenser unit is an ignition source requiring the full setback clearance. The AC unit is often on the side of the house closest to the desired tank location. Verify this distance before placement.
- Tank positioned against the house wall: Occasionally, homeowners request the tank be placed directly against an exterior wall for aesthetic reasons (out of sight). This violates the 10-foot minimum from building walls. The tank must be in a free-standing, accessible location.
- Insufficient setback from property line: On small lots, achieving 10-foot setbacks from both the house and the property line simultaneously can be challenging. If your lot is narrow, work with your installer to identify the site geometry before applying for the permit.
- Forgetting the electric meter: The electric meter on the exterior of the home is almost always on the same side as the utility easement — which is also often the side closest to the street and the most convenient tank location. Do not place the tank within 10 feet of the electric meter.
Setbacks for Specific Situations
Propane tank in a garage or enclosed space
Propane tanks — of any size — may not be stored inside garages, basements, under porches, or in any enclosed space. This is an absolute prohibition under NFPA 58, not a setback issue. LP gas is heavier than air and will accumulate in low-lying enclosed spaces, creating an explosion risk. Tanks must be in open, well-ventilated outdoor locations.
Tank near a pool or hot tub
If you have a pool or hot tub with electric equipment (pump, heater, lighting), those electrical features count as ignition sources. The 10-foot (or applicable) setback applies. Additionally, pool heaters fueled by propane require their own piping permit and are typically inspected separately from the tank installation.
Tank on a sloped property
NFPA 58 does not specifically address slope, but your local AHJ may require additional setback on the downhill side of a tank on steeply sloped land. LP gas vapor, being heavier than air, will flow downhill if released. Tanks on slopes should generally be positioned so that the downhill direction is away from structures and ignition sources.
No — NFPA 58 sets a minimum 10-foot setback from building walls and openings for tanks of any size, including small 120-gallon or 250-gallon tanks. The 10-foot minimum is not relaxed for smaller tanks. If 10 feet of clearance is not achievable on your property, you should consult your local AHJ, who may suggest alternative locations, a different tank size, or in some cases a variance if unique site conditions apply.
Yes. Detached garages, barns, storage sheds, and other outbuildings count as "buildings" under NFPA 58 and require the same setbacks as the main house. If your detached garage has an electric panel, it also counts as an ignition source. Plan your tank placement with setbacks from all structures on the property, not just the main house.
NFPA 58 does not specifically address fences. A standard wood or vinyl residential fence is not a "building" and does not require the 10-foot structural setback. However, fences at the property line often represent the property line itself, which does require a 10-foot setback. Additionally, fences can obstruct the ventilation around a tank and reduce emergency access. Many inspectors and AHJs require tanks to be accessible from at least three sides with no fencing within 3–5 feet. Check with your local AHJ for their specific fence proximity rules.
Your licensed LP gas installer is responsible for verifying setback compliance before finalizing tank placement. During the permit application, the site plan you submit should show all setback distances. The building or fire inspector will then independently verify the distances with their own measurements during the inspection. If the inspector finds that setbacks are not met, the tank must be moved before the permit can be approved. To avoid this expensive repositioning, verify setbacks yourself before your installer arrives using a tape measure and our Setback Calculator.