The short answer

When buying a house, look beyond cosmetics at four things: the building’s structure and systems (roof, foundation, water, electrical, HVAC), the public records (owner of record, liens, permits and taxes), insurance and flood exposure (flood zone, claims history, quotes), and the true cost after closing (reassessed taxes, HOA fees and repairs). Inspectors answer the first; records, the seller and insurers answer the rest.

Key takeaways

  • The median owner-occupied US home is 42 years old, so aging roofs, plumbing and electrical are the norm, not the exception.
  • A home inspection is visual and does not determine code compliance; permits and records fill that gap.
  • Match every visible renovation to a permit, and every “no” on the disclosure to the records.
  • Check your own future tax bill; in California and Florida it can reset at sale.
42 yearsMedian age of owner-occupied US homes in 2024NAHB analysis of Census ACS
~47%Owner-occupied homes built before 1980NAHB
21%First-time buyers’ share of purchases (NAR 2025 Profile)NAR
40Median age of first-time buyers, a record highNAR
Housing stock

Median age of owner-occupied US homes

2005
31 years
2024
42 years
NAHB analysis of US Census Bureau American Community Survey data, published March 2026. Source.

1. The building: physical red flags

Physical checks and the professional who answers each
Look forWhy it mattersWho can confirm
Water stains, musty smells, fresh paint on one ceiling patchPast or active leaks; possible insurance claimsInspector; seller’s CLUE report
Cracks wider than a hairline, sticking doors, sloping floorsPossible foundation movementInspector; structural engineer
Roof age and patched areasReplacement cost; insurability in some marketsInspector; roofer; insurer
Old electrical panels, ungrounded outlets, DIY wiringSafety and insurance acceptanceInspector; electrician
Water heater and HVAC ageNear-term replacement costsInspector; data plates
Sewer line, septic or wellExpensive failures not visible in a walk-throughSewer scope; septic and well tests
Pre-1978 constructionLead-based paint disclosure and testing rightsSeller disclosure; lead inspector

2. The records: what the listing doesn’t show

  1. Owner of record matches the seller

    Compare the assessor record and latest deed with the seller named in the contract; trusts, estates and LLCs need authority checked.

    Keep: Deed and parcel ID.

  2. Liens, judgments and releases

    Look for recorded mortgages, liens and their releases. A blank online search is not proof; your title company confirms.

    Keep: Lien search results and questions for title.

  3. Permits for visible work

    Additions, garage conversions, decks and new kitchens should match permits with a final inspection. Open or expired permits can delay closing.

    Keep: Permit numbers and status.

  4. Tax status and future bill

    Check delinquencies and exemptions that end at sale; estimate your own reassessed bill.

    Keep: Current bill and your estimate.

3. Insurance and flood

4. Costs after closing

  • Property taxes that reset at sale (California, Florida).
  • HOA dues, reserves and special assessments.
  • Deferred maintenance flagged in the inspection.
  • Insurance premiums in high-risk areas.
Red flags are prompts, not verdicts. A water stain may be an old, repaired leak; a missing permit may sit in an older archive. The goal is to turn each one into a question with an answer before your deadline.

Questions people ask

What are the biggest red flags when buying a house?

Signs of water intrusion, foundation movement, an old roof, outdated electrical, unpermitted additions, recorded liens, a flood-zone location without insurance history, and disclosure answers that contradict the records.

What should I check before making an offer?

The flood zone, the owner of record, visible renovations against permit records, the tax history and any HOA obligations. These take minutes to hours and can change your price.

Does a home inspection check permits?

Usually not. Inspectors evaluate visible condition and are not required to determine code compliance; permits come from the building department.

Should I buy a house with unpermitted work?

It depends on the work, the cost to permit or remove it and how your lender and insurer respond. Get the building department’s view and a contractor estimate before deciding.

PropertyDataCheck early access

Want the records side done for you?

Send the address. A pre-offer property check matches the parcel and assembles the owner of record, liens, permits and flood zone, with each gap written up as a question for your inspector, agent or title company.

  • Parcel & owner of record matched
  • Liens, permits & flood zone in one place
  • Gaps turned into questions for your team

Any starting point is welcome. Continuing shares your entry with us. Privacy

Early access request. Reports are not available yet.

Sources & method

We start with the agency or statute that governs each rule and link to it directly. Figures carry their source and date. Rules and forms change; confirm the current version with the responsible office or a qualified professional.

  1. NAHB: how old is today’s housing stock (March 2026)
  2. NAR 2025 Profile of Home Buyers and Sellers
  3. ASHI Standard of Practice
  4. EPA: lead-based paint disclosure
  5. California BOE: Proposition 13
  6. Florida DOR: Save Our Homes
  7. CFPB: closing on your home

Reviewed September 25, 2026 by the PropertyDataCheck editorial team. Corrections: info@propertydatacheck.com. How we research and update guides.