When an appraiser walks through your house, they are documenting four things: how big it is, what it was built with, what shape it’s in now, and how it compares to recent sales nearby. That’s what an appraiser looks for when appraising a house. The visit itself usually runs 30 minutes to an hour for a single-family home, but the number they produce afterward is built from measurements, standardized ratings, and comparable sales data pulled together into a single opinion of market value.
Square Footage Comes First
Nothing moves appraised value more than the size of the home, so the appraiser measures carefully. Fannie Mae requires appraisers to follow the ANSI Z765 standard, which sets specific rules: measurements go to the nearest inch, finished rooms need ceiling heights of at least seven feet, and any space that is even partially below ground gets reported separately as below-grade area.1Fannie Mae. Standardizing Property Measuring Guidelines
What counts is “above-grade finished area,” meaning livable, finished space that sits entirely above ground level. This distinction matters more than people realize. A beautifully finished basement with a home theater and wet bar gets noted on the report, but it contributes less to the appraised value per square foot than the same space would if it were above grade.
Sloped-ceiling rooms like finished attics follow another ANSI rule: at least half the finished floor area must have a ceiling height of seven feet or more, and no portion can drop below five feet.1Fannie Mae. Standardizing Property Measuring Guidelines Space that doesn’t meet these thresholds gets carved out of the finished count entirely. Unpermitted additions create a related problem: the appraiser may not count that square footage at all, or may flag it as a risk factor.
Quality of Construction
The appraiser assigns a standardized quality rating from Q1 (the highest) to Q6 (the lowest), reflecting the materials, craftsmanship, and architectural design of the home. These ratings come from the Uniform Appraisal Dataset and appear directly on the appraisal form your lender reviews.2Fannie Mae. Property Condition and Quality of Construction of the Improvements
- Q1: Architect-designed, one-of-a-kind homes built with the highest-grade materials and workmanship throughout.
- Q2: Custom or heavily modified designs with high-quality finishes and detailed ornamentation, often built on individual lots.
- Q3: Above-standard homes with notable exterior detail and well-finished interiors, built from quality plans with upgraded materials.
- Q4: Standard builder-grade construction that meets code, with adequate design and some upgrades. This is the most common rating for tract-built homes.
- Q5: Economy construction focused on basic functionality, with plain design, minimal finishes, and stock materials.
- Q6: Lowest-cost construction, sometimes built without formal plans, with minimal mechanical systems and basic materials.
The rating reflects what was originally built, not what’s been renovated. A Q4 home with a gorgeous kitchen remodel doesn’t jump to Q2. The renovation shows up in the condition rating instead.
Property Condition
Separate from quality, the appraiser rates the home’s current physical condition on a C1-to-C6 scale. Where quality asks what the house was built with, condition asks how it has held up. This rating captures wear, maintenance, and whether components have been updated or are failing.2Fannie Mae. Property Condition and Quality of Construction of the Improvements
- C1: Brand new, never occupied, zero depreciation.
- C2: Recently and completely renovated to like-new condition, or nearly new with no deferred maintenance.
- C3: Well maintained with limited wear. Some components may be updated, but it hasn’t been fully renovated.
- C4: Adequately maintained with some minor deferred maintenance and normal wear. All major systems still function. This is where most resale homes land.
- C5: Noticeable deferred maintenance with significant repairs needed. Components are worn or outdated.
- C6: Major damage or serious deferred maintenance affecting structural integrity or safety. If any part of the home warrants a C6, the entire dwelling receives that rating.
The C6 rule is the one that catches people off guard. A house in otherwise decent shape can earn a C6 if the appraiser spots one significant structural or safety issue. Kitchen and bathroom renovations are the most reliable way to push a condition rating upward, though the appraiser will look for permits on major work.
Major Systems and Visible Safety Issues
The appraiser checks the age and general condition of the HVAC, electrical, plumbing, and roofing systems. This is not a home inspection. The appraiser won’t run diagnostic tests or crawl through ductwork, but they are required to note any obvious problems that affect habitability or marketability. Think visible water damage on ceilings, a furnace that clearly doesn’t run, exposed wiring, or foundation cracks visible from the basement.
The roof gets close scrutiny. The appraiser evaluates its remaining useful life and current condition, checking for missing shingles, sagging areas, or signs of leaking. A newer roof adds value; one that’s visibly failing will result in a downward adjustment. The same logic applies to siding, windows, and exterior paint. The appraiser is estimating how much life these components have left and what a buyer would factor into their offer.
The Lot and the Neighborhood
The appraiser evaluates more than the house itself. Lot size, shape, and topography all get documented and compared to the neighborhood norm. An unusually large lot in a subdivision of quarter-acre parcels adds value; an oddly shaped or steeply sloped lot can subtract it. Flood zone designations are noted because they affect both insurability and buyer demand.
Accessory structures like detached garages, workshops, sheds, and pools get valued based on how much they contribute to marketability. An in-ground pool adds more value in warm climates than in northern states where the swimming season is short. The appraiser also confirms that the property’s zoning classification matches its actual use. A legal single-family residence is straightforward; a property with a non-conforming use or a zoning violation introduces risk that pulls value down.
External influences round out the site analysis. Proximity to good schools, parks, and employment centers supports higher values. Heavy traffic, commercial encroachment, nearby power lines, or railroad tracks prompt downward adjustments based on how the local market perceives them. The appraiser is estimating buyer resistance: how much less would a typical purchaser pay because of that cell tower next door? That estimate gets baked directly into the final number.
Comparable Sales
The backbone of a residential appraisal is the sales comparison approach. The appraiser finds recently sold homes similar to yours and uses their sale prices to estimate your home’s value, looking at closed sales, pending contracts, and active listings. Fannie Mae requires the report to include a twelve-month sales history for each comparable used.3Fannie Mae. Sales Comparison Approach Section of the Appraisal Report
The best comps come from the same subdivision or a directly competing neighborhood and share key characteristics with the subject: similar age, architectural style, square footage, and quality of construction. Most appraisals include at least three comparable sales, and the appraiser must verify the sale data through a disinterested source, meaning someone without a financial stake in the transaction.3Fannie Mae. Sales Comparison Approach Section of the Appraisal Report In a slow rural market where few homes trade hands, the appraiser may need to reach further geographically or go back further in time, but the report should explain why.
How Adjustments Produce the Final Number
No two homes are identical, so the appraiser adjusts each comp’s sale price to account for differences with the subject property. The adjustments always apply to the comp, never to the subject. If a comp has a feature the subject lacks, like a three-car garage versus a two-car garage, the appraiser subtracts dollars from that comp’s price. If the comp is inferior in some way, dollars get added.4Fannie Mae. Adjustments to Comparable Sales
Common adjustments include differences in square footage (often calculated on a per-square-foot basis), lot size, number of bedrooms and bathrooms, garage capacity, condition, and age. Non-physical factors also get adjusted. If the seller paid the buyer’s closing costs, the appraiser backs that concession out of the sale price to reflect what the home truly sold for on its own merits.
After adjusting all the comps, the appraiser reconciles the adjusted prices into a single opinion of value. This is not an average. The appraiser gives the most weight to the comp that required the fewest and smallest adjustments, the one most naturally similar to the subject property. A comp that needed only a minor square footage adjustment holds far more influence than one requiring adjustments for age, condition, lot size, and garage count.
If the Buyer Is Using FHA or VA Financing
If the loan is FHA, the appraisal includes a layer of minimum property requirements that go beyond what a conventional appraisal demands. FHA appraisals enforce health and safety standards set by HUD, and a home that doesn’t meet them can’t close with FHA financing until the issues are fixed.
The general HUD rule is that any component reaching the end of its useful life within two years should be replaced. For the roof, the covering must prevent moisture from entering and provide reasonable future utility.5U.S. Department of Housing and Urban Development. HUD 4150.2 Property Analysis Other common FHA triggers include chipping or peeling paint in homes built before 1978 (due to lead-based paint concerns), inadequate drainage around the foundation, non-functional plumbing or electrical systems, and evidence of termite damage or dampness in basements and crawl spaces. VA appraisals follow a similar philosophy with their own set of minimum property requirements.
How To Prepare for the Visit
You can’t control comparable sales or neighborhood factors, but you can control how the appraiser perceives your property’s condition. Before the visit, handle the obvious maintenance items: fix leaking faucets, replace burned-out light bulbs, repair cracked windows, and make sure all doors open and close properly. These aren’t value-boosting renovations. They prevent the appraiser from downgrading your condition rating for visible deferred maintenance.
On the exterior, clean gutters, touch up peeling paint, mow the lawn, and repair any cracked walkways or driveway surfaces. A home that looks neglected on the outside sets a negative expectation before the appraiser crosses the threshold.
The most underrated preparation is documentation. Put together a one-page summary of every improvement you’ve made, with approximate costs and dates. Include permit records for any additions, electrical upgrades, or system replacements. If you replaced the roof three years ago, the appraiser needs to know that. A roof that looks five years old and one confirmed at three years old get treated differently in the condition analysis. Having a recent survey or floor plans available also helps, particularly if your home has an unusual layout or additions that might be confusing to measure.
Don’t bother with deep cleaning or staging. The appraiser isn’t evaluating your taste in furniture or how organized your closets are. They’re documenting the bones: square footage, room count, system condition, quality of finishes, and physical deficiencies. A clean house is fine; a professionally staged house doesn’t add a dollar to the appraised value.