Home Inspection Checklist: What Buyers Need to Know

April 17, 2026

A home inspection is the most important $400-$600 you'll spend during the home buying process. It's your one shot to identify problems before they become your problems. Here's exactly what inspectors check, what the red flags look like, and how to use the findings to your advantage.

What a Home Inspector Checks

A licensed home inspector evaluates the home's major systems and structural components following standards set by the American Society of Home Inspectors (ASHI) or the International Association of Certified Home Inspectors (InterNACHI). The inspection covers:

Structural and Foundation

• Foundation walls and slab: Cracks wider than 1/4 inch, horizontal cracking in block walls, and evidence of shifting or settling. Minor hairline cracks are normal; stair-step cracks in brick or block are not.
• Load-bearing walls and beams: Sagging, bowing, or evidence of improper modifications (like removed load-bearing walls without proper headers).
• Floor levelness: Floors that slope more than 1 inch over 15 feet may indicate foundation settlement. The inspector uses a level and marble test.

Foundation repairs range from $500-$3,000 for minor crack sealing to $10,000-$50,000+ for pier installation or wall stabilization. Foundation issues are the most expensive category of home repair and the most common reason buyers walk away from a deal.

Roof

• Shingle condition: Curling, cracking, missing, or granule loss on asphalt shingles indicate aging. Most asphalt roofs last 20-30 years.
• Flashing: Metal or rubber seals around chimneys, vents, and skylights. Failed flashing is the number-one cause of roof leaks.
• Gutters and drainage: Proper slope, no standing water, downspouts directing water away from the foundation.
• Attic ventilation: Proper intake and exhaust ventilation prevents moisture buildup and extends roof life.

A full roof replacement costs $8,000-$25,000 depending on size and material. If the roof is past its expected life, use this as negotiation leverage — either a price reduction or a credit at closing.

Plumbing

• Water pressure: Should be 40-80 PSI. Low pressure may indicate corroded pipes or municipal supply issues.
• Drain flow: Slow drains in multiple fixtures suggest a main line problem, not just a local clog.
• Pipe material: Polybutylene (gray plastic, common 1978-1995) and galvanized steel are prone to failure. Copper and PEX are preferred.
• Water heater: Age, condition, and capacity. Tank heaters last 8-12 years. Replacement costs $1,200-$3,500.
• Evidence of leaks: Stains on ceilings, mold under sinks, soft spots in flooring near bathrooms and kitchens.

A sewer line scope ($150-$350) is a separate inspection but highly recommended for homes built before 1980. Sewer line replacement costs $5,000-$20,000 — finding this before closing saves you a nightmare.

Electrical

• Panel condition: Federal Pacific and Zinsco panels are fire hazards and should be replaced. Panel replacement costs $1,500-$4,000.
• Wiring type: Knob-and-tube (pre-1940s) and aluminum wiring (1960s-1970s) are safety concerns. Rewiring costs $8,000-$20,000 for a whole house.
• GFCI protection: Required in bathrooms, kitchens, garages, and exterior outlets. Absence is a code violation and a safety issue.
• Grounding: Ungrounded outlets (two-prong) are common in older homes. Upgrading costs $100-$300 per outlet.

HVAC (Heating, Ventilation, Air Conditioning)

• Age and condition: Furnaces and AC units last 15-20 years. Units over 15 years old are approaching end-of-life.
• Heat exchanger: A cracked heat exchanger in a gas furnace is a carbon monoxide hazard and requires immediate replacement.
• Ductwork: Disconnected, crushed, or uninsulated ducts reduce efficiency by 20-40%.
• Refrigerant type: R-22 (Freon) was phased out in 2020 and is extremely expensive to service. Systems using R-22 should be replaced.

A new HVAC system costs $5,000-$12,000. If both the furnace and AC unit are over 12 years old, budget for replacement within 3-5 years and negotiate accordingly.

Interior and Exterior

• Windows: Seal failure (foggy double-pane glass), operational issues, and frame rot. Replacement costs $300-$1,000 per window.
• Doors: Alignment issues (sticking doors may indicate foundation movement), weatherstripping condition, and lock function.
• Siding and trim: Wood rot, pest damage, and paint failure. Residing a home costs $8,000-$25,000.
• Grading and drainage: Soil should slope away from the foundation. Improper grading causes water intrusion, which causes foundation damage.
• Basement and crawlspace: Moisture, standing water, mold, pest evidence, and insulation condition.

Specialty Inspections Worth Ordering

The standard inspection doesn't cover everything. Depending on the home's age, location, and condition, consider these add-ons:

• Radon test ($125-$200): Radon is an odorless, cancer-causing gas that seeps into basements. Mitigation costs $800-$1,500 if levels exceed 4 pCi/L.
• Termite/pest inspection ($75-$150): Required by some lenders. Termite damage repair costs $2,000-$10,000+ depending on extent.
• Sewer scope ($150-$350): Essential for older homes. Reveals root intrusion, bellied pipes, and damaged lines.
• Mold inspection ($300-$600): Order if you see staining, smell mustiness, or the home has had water damage. Mold remediation costs $1,500-$9,000.
• Well and septic ($300-$600): Required if the home is on private water and sewer. Septic replacement costs $15,000-$30,000.

Red Flags That Should Make You Walk Away

Not every inspection finding is a deal-breaker. But these are serious:

1. Active foundation failure: Significant horizontal cracking, walls bowing inward, or floors with severe slope. Repair costs can exceed $50,000 and may not fully resolve the issue.
2. Extensive mold from ongoing water intrusion: If the source of water hasn't been fixed, mold will return. Remediation plus waterproofing can exceed $15,000-$25,000.
3. Failing sewer main: A collapsed or heavily root-damaged main sewer line under the foundation requires excavation. Costs: $10,000-$25,000.
4. Unpermitted structural modifications: Removed load-bearing walls, enclosed garages, or added square footage without permits create liability, insurance, and resale problems.
5. Environmental hazards: Asbestos requiring abatement ($5,000-$20,000), lead paint in poor condition (especially with children), or underground oil tanks ($10,000-$30,000 to remove).

Using Inspection Findings to Negotiate

The inspection report is a negotiation tool. Here's how to use it effectively:

What to Negotiate

• Safety hazards: Electrical issues, gas leaks, structural problems — these are non-negotiable and sellers rarely push back.
• Major system failures: HVAC, roof, plumbing, and electrical systems near end-of-life are fair game for credits or price reductions.
• Code violations: Unpermitted work, missing GFCI outlets, and improper venting are legitimate repair requests.

What Not to Negotiate

• Cosmetic issues: Paint, carpet condition, outdated fixtures. You saw these when you toured the home.
• Normal wear: Minor settling cracks, some grout deterioration, weathered deck boards. These are maintenance, not defects.
• Everything on the report: Sending a 40-item repair list alienates the seller. Focus on the 3-5 most significant and expensive items.

Negotiation Strategies

Work with your buyer's agent to determine the best approach:

• Credit at closing: The seller gives you $5,000-$15,000 at closing to handle repairs yourself. This gives you control over contractors and timing.
• Price reduction: A permanent reduction in the sale price. This also lowers your loan amount and monthly payment.
• Seller completes repairs: The seller hires contractors to fix issues before closing. Get receipts and verify the work during your final walkthrough.

The average inspection-related negotiation results in $3,000-$10,000 in credits or price reductions. On a $400,000 home, that's significant — and it's your buyer's agent's job to secure it.

Attending the Inspection

Always attend your home inspection. Plan to arrive for the last hour when the inspector walks you through findings. Ask questions, take photos, and have the inspector point out the exact location and severity of every issue. The written report is useful, but seeing problems in person gives you context that photos don't.

A home inspection isn't a pass/fail test — it's an information-gathering exercise that protects you from making a $400,000 mistake. Invest the $500-$1,500 and use the findings wisely.

Need an agent who knows how to leverage inspection findings? Browse buyer's agents on The Realtor Rankings who specialize in protecting your investment.