Why evidence is the whole game
Every property tax appeal, regardless of county, lives or dies on evidence. Assessment review boards — whether called a Board of Equalization, a Board of Assessment Review, or a hearing officer panel — are not there to negotiate. They exist to determine whether the assessor's number is accurate given the market and the property's actual condition. Frustration, fairness arguments, and comparisons to a neighbor's bill carry no weight. Documented facts do.
The NTUF's research puts successful residential appeals in the 40–60% range nationally, but the homeowners who win aren't doing anything exotic. They're presenting organized, specific evidence while most appellants show up empty-handed. That gap is what the appeal process guide is built around, and this page gives you the evidence layer in detail.
Comparable sales: the three rules boards actually apply
Comparable sales — comps — are the primary evidence in nearly every residential appeal because assessors derive market value from sales data, and the board uses the same methodology to evaluate your challenge. The question is always: what did similar homes actually sell for before the assessment date? Three rules determine whether a comp will hold up under scrutiny:
- Distance. In urban and suburban neighborhoods, stay within a half-mile to one mile of your property. Boards discount comps from different subdivisions, school zones, or across major roads — even at similar prices — because micro-location is a real price variable. Rural parcels may require a wider radius, but proximity always strengthens the argument.
- Recency. Sales should have closed within the twelve months before your assessment date, with the most recent weighted highest. Boards treat older sales as weaker evidence of current value; sales from beyond eighteen months back are often dismissed unless the market was demonstrably flat during that period.
- Similarity. Target homes within 20% of your square footage, the same bedroom and bathroom count, a comparable year built, and the same general property type — single-family, townhome, or condo. A 1,400-square-foot ranch cannot comp against a 2,200-square-foot two-story, even on the same block.
Three comps is the floor; five that all point the same direction gives the board a clear pattern. More than seven rarely adds persuasive weight and can make the presentation harder to follow. Screen each candidate against all three rules before it goes on your sheet.
Record-card errors: the fastest win available
Every parcel in a county has a property record card — the assessor's official description of what sits on the land. The county's mass-appraisal model flows directly from these fields, which means a factual error in the card translates into a calculable overcharge. Pull your card from the assessor's online portal and check every field against what you know to be true on the ground:
- Gross living area — the most common error and typically the highest-value catch
- Bedroom and full/half bathroom count
- Basement: finished versus unfinished percentage
- Garage: attached versus detached, number of bays
- Pool, deck, and outbuilding presence and size
- Lot size and acreage
- Year built and effective age
A 200-square-foot overcount on a suburban home can inflate assessed value by thousands of dollars. Assessors almost always concede clear measurement errors before the hearing, which means a record-card correction can resolve an appeal without you ever sitting in front of a board. Document the error with measurements, photos, and — where available — original building plans or permit records. The correction amount flows from the county's own model, so there's no room to dispute the math once the error is established.
Condition documentation: what the mass model can't see
Mass-appraisal models are built on averages. They can price a three-bedroom ranch in a given zip code within a reasonable range, but they cannot account for the foundation crack behind finished drywall, the flat roof that needs full replacement, the HVAC system running on borrowed time, or the fact that a backyard abuts a flood easement. These are condition factors — things that reduce what a real buyer would pay — and they are the third evidence category boards recognize.
Effective condition documentation means dated photographs showing the specific defect (exterior and interior), a written estimate from a licensed contractor quantifying the repair cost, and where available, a home inspection report or structural engineer assessment. The board needs to connect the condition problem to a dollar impact on value: "this roof requires $18,000 in repairs" is evidence; "the roof looks bad" is not.
Condition evidence works best as a supplement to comps rather than a replacement. If you can find a sold comparable that also carried deferred maintenance, its sale price anchors the argument in market terms and makes the condition case much harder to dismiss.
How boards weigh each evidence type — and what that means for preparation
Boards treat the three evidence categories differently in practice. Comparable sales carry the most weight in a contested value hearing because they reflect what buyers actually paid — the definition of market value. A clean set of well-selected comps is the evidence type most likely to produce a negotiated reduction before the formal hearing even begins.
Record-card errors are handled almost mechanically: they are factual disputes, not valuation disputes. Present the error, show your documentation, and in most cases the correction is accepted. The dollar impact flows from the county's own model, so there's no subjective room once the error is confirmed.
Condition evidence is the most subjective of the three and requires the most work to quantify. Boards vary in how much weight they give to deferred maintenance versus functional obsolescence — an awkward floor plan, proximity to a busy road, a lot with drainage problems — but both are legitimate grounds when supported by dollar estimates from professionals.
When you file, organize all three categories on separate, clearly labeled pages and lead with comps. The letter template structures the argument in exactly this order, and the DIY appeal walkthrough covers the hearing itself step by step. One organized package — not a folder of screenshots — is what wins the room.