What a home appraisal error looks like and why it matters

A home appraisal is an official estimate of what your house is worth, ordered by your lender during a mortgage or refinance. The appraiser walks through your home, measures rooms, checks comparable sales in your neighborhood, and produces a written report with a dollar value. If that value comes in lower than the purchase price or your expected refinance amount, your loan may not go through — or you may have to put down more money or accept a smaller loan.

Appraisal errors happen. An appraiser might miss a recent kitchen renovation, miscount square footage, use the wrong comparable homes, or undervalue upgrades you've made. When the number feels wrong, you have the right to challenge it. The process is straightforward: you gather evidence, write a rebuttal letter, and send it to the appraiser or lender. Many errors get corrected this way.

Key Takeaways

  • You can challenge an appraisal by submitting a written rebuttal with photos, receipts, and comparable sales data to the appraiser or your lender within days of receiving the report.
  • Common errors include missed renovations, wrong square footage, incorrect property features, and comparable homes that don't match your neighborhood or condition.
  • The appraiser may revise the report, order a new appraisal, or stand by the original number — all outcomes are possible and you should know which one your lender will accept.
  • If the appraisal still comes in low after your challenge, you can request a second appraisal from a different appraiser, though your lender decides whether to order one.

Spotting the mistake in your appraisal report

Read the appraisal report line by line. The appraiser lists the property address, lot size, year built, square footage, number of bedrooms and bathrooms, roof type, foundation, heating and cooling systems, and any recent updates. They also list the comparable homes they used — usually three to five similar houses that sold recently nearby. Check every fact against what you know about your house.

Common errors include: square footage listed as 1,800 when your deed says 2,100; a finished basement counted as unfinished; a new roof or HVAC system not mentioned; a recent kitchen or bathroom remodel omitted; or comparable homes that are in a different school district, on a busy street, or significantly smaller or larger than yours. If the appraiser visited during winter and missed mature landscaping, or if they used sales from two years ago when your neighborhood has appreciated, those are also red flags.

Pull your property deed, any permits for work you've done, and recent property tax records. These documents show what the appraiser should have seen. Take photos of any upgrades — new flooring, appliances, paint, fixtures — dated if possible. If you know the square footage from a home inspection or builder documents, have that ready too.

Gathering evidence before you write your rebuttal

Your rebuttal is only as strong as the evidence behind it. Start by documenting what the appraiser got wrong. If they missed a renovation, collect the contractor invoice, permit paperwork, and before-and-after photos. If square footage is wrong, pull your home inspection report, the original builder specs, or a recent measurement from a real estate agent's listing sheet. If the comparable homes are off, find three to five homes in your actual neighborhood that sold in the last three to six months and are truly similar — same size, same condition, same street type.

Real estate websites like Zillow, Redfin, and your county assessor's website show recent sales and property details. You can also call a local real estate agent and ask them to pull comparable sales for your address — many will do this for free. Write down the address, sale price, sale date, square footage, lot size, and any major differences from your home (older roof, smaller lot, needs work). This comparison is powerful because it shows the appraiser used the wrong homes.

Organize everything in a folder: photos, invoices, permits, your property deed, the comparable sales list, and any professional reports (home inspection, survey, contractor estimate). You do not need a lawyer or paid appraiser to challenge — your own evidence is enough.

Writing and submitting your rebuttal letter

Keep the letter short and factual. Address it to the appraiser by name if you have it, or to your lender's appraisal department. State the appraisal value, explain what you believe is wrong, and provide specific evidence. Do not argue about the appraiser's judgment or use emotional language. Stick to facts: "The appraisal lists 1,800 square feet. Our home inspection from March 2023 documents 2,100 square feet. The finished basement was not mentioned in the report, though it was completed in 2019 with a permit from the city."

Include a list of the comparable homes the appraiser used and explain why they do not match yours. Then list your own comparables — homes in the same neighborhood, similar size and condition, sold in the last six months. Show the price per square foot for each. If your comparables are higher, that supports a higher appraisal value.

Attach copies (not originals) of your evidence: photos, invoices, permits, the home inspection report, and your comparable sales sheet. Do not send originals — keep those for your records. Email or mail the letter to the appraiser directly if you have their contact information, or send it to your lender's appraisal department. Ask for a delivery confirmation or read receipt so you know it arrived. Most lenders require the rebuttal within 10 to 15 days of the appraisal report date, so act quickly.

What happens after you submit your rebuttal

The appraiser will review your evidence and decide whether to revise the report, order a new appraisal, or stand by the original number. This usually takes five to ten business days. You should hear back from your lender, not directly from the appraiser. The lender will tell you the outcome: revised appraisal, new appraisal ordered, or original appraisal upheld.

If the appraiser revises the report and the new value is higher, your loan can move forward. If they order a new appraisal, a different appraiser will visit your home and produce a fresh report — this takes another week or two. If they uphold the original appraisal, your options narrow: you can request a second appraisal (though your lender decides whether to order one), renegotiate the purchase price with the seller, put down more money, or walk away from the deal.

Ask your lender what they will accept. Some lenders will order a second appraisal if the first one is disputed. Others will not. Knowing this before you submit your rebuttal helps you plan your next step if the challenge does not work.

When to request a second appraisal

If your rebuttal does not change the appraiser's mind and you still believe the value is wrong, you can ask your lender to order a second appraisal from a different appraiser. This is not the same as a rebuttal — it is a completely new appraisal by someone else. The second appraiser may see things differently and come in higher.

Second appraisals cost money — usually $400 to $600 — and you typically pay upfront. Your lender decides whether to order one, so ask them directly: "Will you order a second appraisal if I pay for it?" Some will, some will not. If they will, ask whether they will use the higher of the two appraisals, average them, or use the second one only if it is significantly higher. Get this in writing before you pay.

A second appraisal makes sense if you have strong evidence the first one is wrong and you are confident a different appraiser will see it. It does not make sense if the first appraiser's logic was sound and you straightforward disagree with the market value. Be honest with yourself about whether the evidence supports a higher number.

Appraisal errors you cannot fix with a rebuttal

Some appraisal issues are not errors — they are the appraiser's professional judgment about market value. If the appraiser says your neighborhood is declining, or that homes in your area are not selling well, or that your home needs work, those are opinions based on market data, not mistakes. You can argue with the comparable homes they chose, but you cannot argue with their conclusion about what the market will bear.

If your home genuinely needs a new roof, foundation work, or major repairs, the appraiser will factor that into the value. A rebuttal will not change that — only fixing the problem will. Similarly, if your home is in a less desirable location or school district than the comparable homes, the appraiser's lower value may be correct. In these cases, a second appraisal is unlikely to help.

Focus your rebuttal on factual errors: missed features, wrong square footage, incorrect property details, or bad comparable homes. Do not waste time arguing about the appraiser's market assessment or their judgment about condition unless you have concrete evidence they are wrong.

Frequently Asked Questions

How long do I have to challenge an appraisal?

Most lenders require you to submit a rebuttal within 10 to 15 days of receiving the appraisal report. Check your loan documents or call your lender to confirm the important date. After that window closes, you typically cannot challenge the appraisal through the normal rebuttal process, though you may still request a second appraisal.

Do I need to hire an appraiser to challenge the appraisal?

No. You can write a rebuttal yourself using your own evidence — photos, invoices, permits, and comparable sales data. Many successful rebuttals come from homeowners, not professionals. A paid appraiser review can help if you want a second opinion, but it is not required.

What if the second appraisal also comes in low?

If both appraisals are low and you still believe the value is wrong, you have limited options. You can renegotiate the purchase price with the seller, put down more money to cover the gap, or walk away from the deal. Some lenders will average two appraisals or use the higher one, so ask your lender what their policy is before you order a second one.

Can the appraiser retaliate if I challenge their work?

No. Appraisers are bound by professional standards and cannot lower the appraisal in retaliation for a challenge. If you believe retaliation has occurred, report it to your state's appraisal board or the Appraisal Subcommittee, a federal office that oversees appraiser licensing.

Should I tell the seller about the low appraisal?

In a purchase, the seller usually finds out anyway because the deal may fall through or renegotiation becomes necessary. In a refinance, the seller is not involved. If you are buying and the appraisal is low, talk to your real estate agent about whether to renegotiate the price before you challenge the appraisal — sometimes that is faster than waiting for a rebuttal.