Inspections and Testing in Montgomery County

We run home inspection, radon testing, mold testing and air quality testing across Montgomery County.

4.9 rating, over 4,000 reviews Licensed and insured inspectors 19 communities covered

Schedule an inspection Call (703) 450-6398

A downtown Bethesda street lined with brick apartment buildings and shops in Montgomery County, Maryland

Environmental Testing

Mold Testing High Demand Air Quality Allergen & Pollutant Radon Testing EPA Protocols

Explore More

Inspection Services

Home Inspection Popular Service Commercial Office, Retail, Industrial Termite Inspection WDO Certification

Explore More

Every town we cover in Montgomery County

Montgomery County covers a wide range of housing,. Where a home has been added onto, finished out, or renovated over time, an inspection needs to account for that work. This page is the index to the county: find your town below for a page built around that specific place, its subdivisions where we have them on record, and what an inspection there tends to turn on.

Each town page carries what we actually see in the housing stock there and routes to that town's own service pages. Anywhere inside the county line is a normal booking whether or not it is listed here.

What we see in Montgomery County homes

Construction dates range widely across the county, and many properties have been renovated, finished out, or added onto more than once since they were originally built.

That range means no single checklist covers the whole county. A rowhouse or condo inspection focuses on shared walls, roofing access, and unit-level systems. A single-family subdivision home built decades ago often carries an addition, a finished basement, or an updated electrical panel that needs checking against how the rest of the house was built. On larger rural lots, well and septic systems, longer rooflines, and outbuildings come into play. Grading and drainage matter everywhere, since the county gets wet spring stretches and humid summers that move water toward foundations.

The colorful carousel pavilion at Glen Echo Park in Montgomery County, Maryland — Carousel pavilion at Glen Echo Park

Street corner in downtown Bethesda. — Street corner in downtown Bethesda

Lake at Seneca Creek State Park. — Lake at Seneca Creek State Park

Additions and permit history

Additions are common across the county's older subdivisions. We check how new framing, rooflines and foundations tie into the original structure, since work done without a permit is more likely to skip a step that only shows up later as a leak, a settling crack or an electrical fault.

Grading and drainage

Water moving toward a foundation is one of the most common issues we find, whether the lot is a small suburban yard or a larger rural parcel. We look at how the ground slopes near the house, downspout placement, and where water tends to pool after rain.

Crawlspaces, basements and sumps

Many homes across the county have a basement or crawlspace, and a good number run a sump pump. We check for moisture, past water lines, insulation condition, and whether the sump and its discharge line are actually doing their job.

Most additions and finished basements need a county permit.

Like most jurisdictions in the region, Montgomery County requires a building permit for additions, structural alterations, finished basements and many electrical or plumbing changes. Work done without one is not always visible once drywall and flooring are back in place, which is one reason an inspection looks at how new construction ties into the original structure rather than taking a finished room at face value. If a listing mentions recent work on a property, checking whether it was permitted is worth doing before the inspection, not after.

Confirm current permit requirements with the Montgomery County Department of Permitting Services.

Montgomery County inspections, answered straight

Do you inspect homes throughout Montgomery County, or only in certain towns?

We cover all of Montgomery County, no matter where you're located. Coverage is organized by town, so the fastest way to confirm a specific address is to check the page for the town where the property sits, or contact our office directly. If a property sits right on a county line, we can usually still reach it; ask when you get in touch.

Does the age of a house in this county affect radon risk?

Radon comes from soil gas, not from the age or condition of a house, so new construction and older farmhouses can both test high or low. What matters more is the foundation type and how air moves through it. A basement or slab-on-grade home traps soil gas differently than a home with a raised crawlspace. Because levels vary from block to block, testing is the only reliable way to know what a specific address is dealing with.

The house I'm looking at has an addition. Does that change the inspection?

It can. An addition built without a permit sometimes has structural or electrical shortcuts that are harder to spot once walls and flooring are finished. We look at rooflines, foundation transitions, and how new framing ties into the original structure for signs the work does not match the rest of the house. If permit records are available for the property, comparing them against what is actually built is worth doing before closing.

What does a mold inspection in this area actually check for?

A mold inspection looks at places where moisture collects: basements, crawlspaces, around windows and roof penetrations, and anywhere a house has had a past leak. The county sees humid summers and wet spring stretches, which is enough to sustain growth once moisture gets behind a wall or under flooring. We document visible growth and collect air or surface samples so a lab can identify what is present, rather than guessing from appearance alone.

Book an inspection in Montgomery County

Pick the town above if you want the local detail first, or go straight to scheduling with the address.

Schedule an inspection Call (703) 450-6398

NextDay Inspect
46179 Westlake Dr, Ste 200, Sterling, VA 20165
(703) 450-6398

Licensed, certified and insured

Our inspectors are licensed, insured and continuously trained, and every one is backed by general liability and errors and omissions insurance. These are the credentials that matter for a home inspection; the full roster of certifications, awards and association memberships is a click away.