By Cory Shalaway, Director of Technical Services  ·  Updated September 16, 2026  ·  Based on 1,999 ValueGuard inspection reports

Every home inspection report tells one house’s story. Put 1,999 of them side by side and a different story shows up: the same problems, in the same places, in house after house across Greater Philadelphia. We went through every full home inspection report our inspectors published between September 16, 2025 and September 15, 2026. Then we counted the most common home inspection problems, one finding at a time.

What we found should put buyers at ease. Most of the findings at the top of the list are small and cheap to fix. Some of them still matter a great deal for safety. Here is the list, what each finding means, and what to do about it.

1What are the most common home inspection problems?

The ten most common home inspection problems in Greater Philadelphia are all basic safety gaps, everyday wear or signs of water. Each bar shows the share of homes with that finding at least once. A home with three missing GFCI outlets counts once, not three times. Colors show how our reports usually classify each finding.

Four more findings sit just outside the ten most common home inspection problems. We couldn’t confirm a bathroom fan vented outside in 25.8% of homes. Dry water stains showed up in 22.6%, heating or cooling equipment overdue for service in 22.3%, and loose handrails in 21.9%.

2The most common safety findings: detectors, GFCI outlets and anti-tip brackets

#1 Missing smoke or carbon monoxide detectors (59.6%)

This is the most common finding in our reports, and it isn’t close. In 29.4% of homes, our inspectors flagged missing carbon monoxide detectors on their own. In many others, both smoke and CO detectors were missing, or smoke detectors weren’t in every spot where one is recommended.

It matters. According to the National Fire Protection Association, working smoke alarms cut the risk of dying in a home fire in half. (Seeing an old, yellowed unit? Read why that smoke detector is yellow.) Pennsylvania’s Carbon Monoxide Alarm Standards Act requires sellers to disclose whether CO detectors are installed on the property disclosure statement. The City of Philadelphia goes further and requires owners of one- and two-family homes to install CO alarms.

What to do: Add detectors before you move in. Put smoke alarms inside each bedroom, outside sleeping areas and on every level. Put CO alarms outside sleeping areas and on every level, especially if the home has gas or oil heat, a fireplace or an attached garage.

#2 Missing GFCI protection (42.7%)

A GFCI (ground fault circuit interrupter) outlet shuts off power in a fraction of a second when current leaks to ground, such as through water or a person. Current electrical code calls for GFCI protection near water and in damp spaces: kitchens, bathrooms, laundry areas, garages, basements and outdoors. Many homes in our area were wired before those rules existed.

We found it inside the house in 41% of homes, most often in kitchens, bathrooms and laundry areas, and outside in about 9%. An older home isn’t breaking the rules just because it lacks GFCIs. Adding them is still one of the cheapest safety upgrades you can make.

#4 Missing range anti-tip bracket (32.6%)

An anti-tip bracket is a small metal piece that anchors a freestanding range to the wall or floor. Without it, the weight of a child standing on an open oven door can tip the whole range forward, along with any hot pots on top. The U.S. Consumer Product Safety Commission’s range tip-over safety alert reports 13 deaths from range tip-overs between 2000 and 2008, many of them children under 10.

Brackets are often left off when a range is replaced or pulled out for cleaning. We found the problem on gas ranges in 23% of homes and on electric ranges in about 10%.

3Stairs and railings: where falls happen

#5 Missing stair handrails (32.2%)

Missing handrails turn up most often on basement stairs and exterior steps. Modern residential code calls for a handrail on stairs with four or more risers. Older homes and do-it-yourself renovations often skip it. Loose handrails were a separate finding in another 21.9% of homes.

#8 Railing gaps wider than 4 inches (26.9%)

Today’s building code limits the openings in a guardrail so a 4-inch sphere can’t pass through, about the size of a small child’s head. Many older porch, deck and stair railings have wider spacing between balusters, or open gaps under the bottom rail. If young children will live in or visit the home, this finding deserves a closer look.

4Everyday wear: doors, lights and outlets

#3 Interior doors that stick or won’t latch (36.9%)

Houses move. Seasonal humidity swells wood, framing settles and hinge screws loosen. The result is a door that rubs the frame or won’t stay closed. It’s usually a quick fix with a screwdriver or a plane. When a lot of doors in the same part of the house bind, our inspectors also look for signs of structural movement nearby.

#6 Light fixtures not working (30.2%)

Often this is just a burned-out bulb. Inspectors don’t change bulbs, though, so we can’t rule out a bad switch, fixture or wiring problem. Ask the seller to replace the bulbs before your final walk-through and confirm every light works.

#7 Loose electrical outlets (30.1%)

An outlet that moves when you plug something in can strain the wire connections behind it. Over time, loose connections can heat up. Most loose outlets just need to be re-secured in the box, but that job belongs to a licensed electrician, not a butter knife.

5Water problems: basement moisture and suspected mold

#9 Basement moisture stains or efflorescence (26.7%)

Efflorescence is the white, chalky crust you see on basement walls. It’s left behind when water moves through masonry and then evaporates. It tells you water has been there, not whether it’s there today. The fix usually starts outside the house: gutters, downspout extensions and grading that slopes away from the foundation.

#10 Suspected mold or fungal growth (26.4%)

We note visible growth that looks like mold. Most of it turns up in basements, followed by crawlspaces and attics. A visual inspection can’t confirm what it is. That takes sampling and lab analysis. This finding rose through the year, from about one in five reports last fall to about one in three this summer, which is consistent with humid-season conditions.

If moisture is a concern, ask about MoistureGuard, our moisture analysis service. It’s included in select inspection packages and available as an add-on. We also offer mold inspections through our team of specialists.

6Do Philadelphia homes have different inspection problems than the suburbs?

Mostly no, but there are a few real differences. 1,190 of the reports were for homes in Philadelphia. The other 809 were elsewhere in our service area. The most common home inspection problems look almost the same in both, but a few findings split along city and suburban lines.

Philadelphia’s housing stock is older, with many masonry rowhomes built before modern waterproofing and wiring. That likely explains more basement moisture and more knob and tube wiring in the city. Suburban homes are more likely to have garages, crawlspaces and outdoor living areas, which are likely places for missing GFCI protection and fungal growth. See what we look for on our Philadelphia home inspections page.

7What are the biggest red flags in a home inspection?

The top 10 are common, but most are small. The biggest red flags in a home inspection came up less often. These are the findings that usually lead to repair requests, specialist evaluations or price negotiations:

Knob and tube wiring deserves a special mention. It was common in homes built before about 1940. Many insurers restrict or decline coverage while it’s still in use, so find out early in your contract period. Our local field guide to knob and tube wiring explains what to ask and what to budget for.

8What this means for buyers and sellers

A long report is not a bad house. The median report in our study listed 50 findings, and 95% flagged at least one safety concern. That’s what a thorough inspection looks like, not a warning sign. Knowing the most common home inspection problems ahead of time helps you read your own report calmly. What matters is sorting the handful of big items from the dozens of small ones.

Sellers: Most of the top 10 can be fixed in an afternoon for little money. Taking care of them before listing removes easy line items from a buyer’s repair request. A pre-listing inspection shows you exactly where your home stands before buyers see it. See our inspection pricing for options.

We inspect homes across Philadelphia, Delaware County, Montgomery County, Chester County, Bucks County and the Main Line.

Key statistics: home inspection findings in Greater Philadelphia (2025–2026)

Source: ValueGuard Home Inspections analysis of 1,999 residential home inspection reports, inspections dated September 16, 2025 to September 15, 2026. Journalists and bloggers are welcome to cite these figures with a link to this page.

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Written by

Cory Shalaway

Director of Technical Services · ASHI Certified Inspector #248904 · PA #713784

Cory leads technical services for ValueGuard’s inspection team and inspects homes across Greater Philadelphia and the surrounding counties.

215-860-3150  |  Meet Cory and our team