Pennsylvania’s Act 45 tax exemption is widely misunderstood: Act 45 of 1999 is a construction code exemption, not a property tax law. It lets you build a barn, silo, or grain bin without going through the Uniform Construction Code permit process, but it does not lower your tax bill by itself. The property tax savings farmers associate with Act 45 actually come from three separate programs — the automatic exclusions in 53 Pa.C.S. § 8811, the farmstead exclusion, and Clean and Green preferential assessment under Act 319.
Knowing which of those three applies to your buildings and your land is what turns “I heard farms don’t pay tax on barns” into an actual number off your bill.
What Act 45 Actually Exempts
Act 45 of 1999, the Construction Code Act, requires building permits and inspections for most new construction in Pennsylvania. Section 403.1(b) carves agricultural buildings out of those requirements entirely. Build a barn, milking parlor, silo, or grain storage facility on your farm and you skip the permit process that residential and commercial builders go through.
That has a tax side effect worth naming clearly: because no permit is filed, the county assessor may not learn about the new structure right away. Relying on that gap is a poor strategy. Assessors do periodic reviews and aerial flyovers, and an unreported structure caught later can trigger a retroactive assessment change. The right move is to claim the property tax programs below, which legally keep qualifying structures off the assessment or reduce their taxed value.
Farm Structures Automatically Excluded From Property Tax
The Consolidated County Assessment Law at 53 Pa.C.S. § 8811 lists specific agricultural structures that are not counted as taxable real estate at all. If your building fits one of these categories and serves the farm it sits on, the county should not be including it in your assessment:1Pennsylvania General Assembly. Pennsylvania Code 53 Pa.C.S.A. 8811 – Subjects of Local Taxation
- Silos used predominantly for processing or storage of animal feed connected to the operation of the farm where the silo sits.
- Freestanding, detachable grain bins and corn cribs used exclusively for processing or storage of animal feed on the farm.
- In-ground and above-ground animal waste containments and composting facilities, used predominantly for processing and storing animal waste connected to the farm’s operation.
- High tunnels: hoop-style structures with metal, wood, or plastic frames covered by plastic or flexible textile, floored with soil, crushed stone, matting, pavers, or a floating concrete slab, used for producing, processing, storing, or sheltering agricultural commodities or storing farm equipment.
The recurring phrase in the statute is “incidental to operation of the farm on which it is located.” A silo on a property that no longer farms does not qualify. A grain bin used to store grain for a commercial operation unrelated to that parcel does not qualify. The structure has to serve the specific farm where it stands.
Notice what is not on the list: general-purpose barns, equipment sheds, milking parlors, produce washing stations, and farm retail buildings. Those may benefit from the programs below, but § 8811 does not automatically remove them from your assessment.
Farmstead Exclusion for Buildings § 8811 Doesn’t Cover
The farmstead exclusion is the second lever. It does not remove a building from the tax rolls; it reduces the assessed value of qualifying farm buildings by a set dollar amount before your tax is calculated. Every qualifying structure on the parcel gets that reduction.
To qualify, the farm has to be at least ten contiguous acres used for commercial agricultural production, and the buildings have to serve one of three purposes: producing or storing farm products grown on the property, housing livestock raised for commercial production, or storing machinery, equipment, and supplies used in the farm operation. The farm must also be your primary residence.2PA DCED. Property Tax Relief Through Homestead Exclusion
Two practical points. First, the exclusion only functions in school districts that have approved it, generally funded through state property tax relief allocations. Second, the deadline is firm: for a tax year that begins in July or January, you must file your application with the county assessment office by the preceding March 1. Your school district is required to notify you by December 31 each year if your property is not approved or if the approval is expiring.2PA DCED. Property Tax Relief Through Homestead Exclusion
Clean and Green Preferential Assessment for the Land
Where § 8811 and the farmstead exclusion address buildings, Clean and Green (Act 319) addresses the land itself. It reduces assessed value by taxing your enrolled property based on its agricultural use value rather than its fair market value. In areas where development has pushed market values well above what the land is worth as a working farm, the savings can be significant.3Commonwealth of Pennsylvania. Clean and Green
To enroll, the parcel must be at least ten acres or generate at least $2,000 in annual gross income from agricultural products. The entire tax parcel has to be enrolled; you cannot enroll part of one. The land must fall into one of three use categories: agricultural use, agricultural reserve, or forest reserve. Enrollment creates a covenant with the county to keep the land in that use.
Rollback Taxes if You Change Use
The trade-off with Clean and Green is the rollback. Convert enrolled land to non-agricultural use and you owe the difference between the preferential taxes you paid and what you would have paid at full market value for the previous seven years, plus six percent simple interest per year. On land that has appreciated during enrollment, that number can be large.3Commonwealth of Pennsylvania. Clean and Green
Not every change triggers the full penalty. Pennsylvania recognizes several limited exceptions:
- Split-offs for a residence: you may divide off up to two acres per year (three if local zoning requires it) to build a home. Cumulative split-offs cannot exceed ten acres or ten percent of the originally enrolled land, whichever is less. Rollback applies only to the split-off parcel.
- Rural enterprises: a commercial business on two acres or less of enrolled land is permitted if it doesn’t interfere with farming. Rollback is due only on that portion.
- Oil and gas development: rollback is due only on the acreage directly devoted to the activity.
- Solar and biomass energy: if you install a Tier 1 alternative energy system and most of the energy is consumed on the enrolled tract, no rollback applies.
- Separations: dividing the land into smaller tracts that each still meet program eligibility (generally ten or more acres in a qualifying use) triggers no rollback.
If you decide to voluntarily withdraw land from Clean and Green, notify the county assessor by June 1 of the year before the tax year for which removal is requested. Rollback taxes come due at that point.3Commonwealth of Pennsylvania. Clean and Green
How to Claim Each Benefit
For § 8811 structures, contact your county assessment office and confirm the silo, grain bin, animal waste facility, composting structure, or high tunnel is not being counted in your assessed value. If it is, ask what documentation the county needs to correct the record. Practice varies by county.
For the farmstead exclusion, file the application with your county assessment office by March 1 of the year before the tax year you want the reduction to apply. Be ready to show that the farm is at least ten contiguous acres, that the buildings serve commercial agricultural production, and that the property is your primary residence.2PA DCED. Property Tax Relief Through Homestead Exclusion
For Clean and Green, file an enrollment application with the county assessment office including your tax parcel number, a description of how the land is used, and confirmation that the entire parcel meets the acreage or income threshold.
Appealing a Denied Exclusion or an Assessment Increase
If the county denies an exclusion or raises your assessment in a way that ignores your agricultural use, you can appeal to the county Board of Assessment Appeals. The deadlines are strict. You have 40 days from the mailing date on a Notice of Assessment Change to file a written appeal on the board’s form. For annual appeals not tied to a change notice, the deadline is August 1 of the year before the next billing cycle.
Appeals must be in writing, filed in person at the county assessment office or by mail. Fax and phone appeals are not accepted. If the deadline lands on a weekend or federal holiday, you have until the next business day. Keep proof of mailing; a late postmark means rejection.
At the hearing you carry the burden of proof. Bring documentation of the agricultural use: photographs, Clean and Green enrollment confirmation, Agricultural Security Area membership records, and blueprints or plans showing the structure fits one of the § 8811 categories. If the board rules against you, further appeal to the Court of Common Pleas is available, and an attorney is worth consulting before that step.