The data

Interpreting public records for unpermitted additions

Public records often provide clues about unpermitted additions through discrepancies in square footage, room counts, or property descriptions that don't match visible structures. These records rarely explicitly state 'unpermitted,' so you need to look for inconsistencies that suggest unrecorded work.

October 28, 2026 · 3 min read

Start with the recorded square footage and structure type

Compare the square footage listed in public tax records or the county assessor's office with what you observe or what is advertised. A significant difference, especially if the property visually appears larger than its recorded footprint, is a red flag for unpermitted additions.

Also, check the listed structure type. If records say it's a single-family home with a detached garage, but you see a fully enclosed and finished garage or an entirely new detached structure, investigate further. These discrepancies suggest work that might not have gone through the proper channels.

Check the property's permit history for inconsistencies

Most county or city building departments maintain online portals where you can search for a property's permit history. Look for permits issued for significant renovations, additions, or structural changes.

If you observe a new room, a second story, or a major remodel, but find no corresponding permits, this is a strong indicator of unpermitted work. Some counties only keep digital records for recent years, so older unpermitted work might not appear even with a thorough search.

Look at the assessed value history over time

Property tax assessments usually reflect improvements that increase a home's value. If a property's assessed value jumps significantly at a particular point, but there's no corresponding permit activity or market-wide appreciation, it could mean an improvement was made and later discovered by the assessor, but perhaps not permitted.

Conversely, if a visually significant addition was made but the assessed value remains flat for years, it suggests the improvement was never officially recognized, pointing to unpermitted status. This isn't always foolproof, as assessment methods vary.

Compare tax records to satellite or online street view photos

Use historical satellite imagery or street view services to see how a property has changed over time. If you can pinpoint when a new addition or structure appeared, cross-reference that timeframe with the permit history and assessed value changes.

This visual comparison can quickly highlight discrepancies. For example, a new carport that appears between two satellite images but has no permit associated with it is a clear sign to dig deeper.

Understand what public records won't explicitly tell you

Public records rarely explicitly state 'unpermitted addition.' You're looking for absence of evidence, not direct proof. The burden of proof for permitted status often falls on the homeowner or you as the prospective buyer.

Furthermore, what constitutes 'permitted' work can vary by jurisdiction and the age of the structure. Some older additions might predate stricter permitting requirements, making them grandfathered in rather than truly unpermitted.

What to do when you suspect an unpermitted addition

If public records suggest an unpermitted addition, factor the potential risks and costs into your offer. This could include the cost to bring the addition up to code, potential fines, or the impact on resale value and insurability.

You might need to adjust your cash offer calculations significantly. It is not legal advice, but if you have a strong suspicion, consider consulting with a local building inspector or structural engineer before finalizing your offer to understand the full scope of potential issues.

Questions people ask

What if the county records show less square footage than the house visibly has?

That's a strong indicator of an unpermitted addition. The discrepancy means the county hasn't officially recognized the additional space, which could lead to issues with taxes, insurance, or future sale.

Can I rely solely on public records to confirm unpermitted work?

Public records provide strong clues, but they don't always offer definitive proof. They are a starting point for your due diligence. A physical inspection and possibly expert consultation are often necessary to confirm.

Will a permit search always show all past work?

Not always. Older permits might not be digitized, or very minor work might not have required a permit at the time it was done. Focus on major structural changes or additions that would clearly require permits.

Does an unpermitted addition always mean a bad deal?

Not necessarily. It means there's an additional risk and potential cost. If you can acquire the property at a price that accounts for these factors, and you have a clear plan to address the unpermitted work, it can still be a viable deal.