Building Inspection Stages Explained

Inspections are the part of the permit process that actually checks the work. Plan review confirms the design meets code; inspections confirm the building matches the approved plans. They are timed so that each element is seen before the next layer of construction hides it.

The model International Residential Code (IRC) lists the core residential inspections in Section R109.1: foundation (R109.1.1), plumbing, mechanical, gas and electrical rough-in (R109.1.2), floodplain (R109.1.3), frame and masonry (R109.1.4), other inspections the building official requires, including fire-resistance-rated construction (R109.1.5), and final (R109.1.6). Local departments add their own stages and name them differently, but the sequence below covers what most homeowners and contractors will encounter.

The core sequence for new construction and additions

Site and setback

Some jurisdictions inspect the layout before excavation or require a surveyor’s stake-out to confirm the building sits within the setbacks. Erosion control and temporary power may also be checked at this stage.

Footing or foundation

Under IRC R109.1.1, the foundation inspection happens after poles or piers are set or trenches or basement areas are excavated, forms are in place, and any required reinforcing steel is set and supported, but before concrete is poured. It also covers excavations for thickened slabs that will support bearing walls, partitions, structural supports, or equipment. The inspector checks footing width and depth, frost depth, soil conditions, rebar size and placement, hold-down anchors, and clearances. Many departments inspect foundation walls, waterproofing or dampproofing, and under-slab items separately.

Under-slab and underground

Plumbing, electrical conduit, and other systems that will be buried in or below a slab must be inspected and, for plumbing, tested before the slab is poured or the trench is backfilled.

Flood elevation

In a flood hazard area, IRC R109.1.3 requires documentation of the lowest floor elevation (including a basement), prepared and sealed by a registered design professional, once the lowest floor is placed and before further vertical construction. R109.1.6.1 requires elevation documentation again before the final inspection. In practice this is usually a FEMA elevation certificate from a surveyor.

Rough-in: plumbing, mechanical, gas, and electrical

IRC R109.1.2 requires rough inspections before the work is covered or concealed, before fixtures or appliances are set, and before the framing inspection. Inspectors check pipe sizing and slope, drain and vent configuration, pressure or leak tests, gas piping tests, duct and vent clearances, box fill, conductor sizing, grounding and bonding, and required protection of cables. These are often separate inspections, sometimes by different inspectors.

Framing

Under IRC R109.1.4, the frame and masonry inspection happens after the roof, masonry, framing, firestopping, draftstopping, and bracing are in place, and after the plumbing, mechanical, and electrical rough inspections are approved. Inspectors check member sizes and spans, connections and fastening, headers, braced wall panels, stairs, guards, egress window sizes, fire separation between a garage and the house, and that framing was not over-cut for pipes or ducts. In high-wind and seismic regions, departments often add a separate sheathing or shear wall nailing inspection before the exterior is covered.

Insulation and energy

Many departments inspect insulation before drywall to confirm R-values and installation quality match the energy code. In the 2021 IRC energy chapter, Section N1102.4.1.2 requires every new dwelling to be tested for air leakage, with a maximum of 5.0 air changes per hour at 50 pascals, and lets the code official require an approved third party to do the test and submit a signed report. Section N1103.3.5 requires duct leakage testing, either at rough-in or after construction. States often amend these numbers, so check your local energy code.

Drywall or lath

IRC R109.1.5.1 requires an inspection of fire-resistance-rated construction between dwelling units (as in a duplex or townhouse) or required because of location on the property, after the gypsum board or lath is in place but before joints and fasteners are taped or plaster is applied. Some jurisdictions also inspect garage separation walls or exterior lath before stucco.

Final

IRC R109.1.6 calls for the final inspection after the permitted work is complete and before occupancy. It checks the finished project: fixtures and appliances installed, electrical devices and covers in place, smoke and carbon monoxide alarms working, guards and handrails secure, grading directing water away from the foundation, address numbers posted, and any outstanding items from earlier inspections. Separate trade finals are common. For new homes and certain other projects, a passed final leads to a certificate of occupancy.

Inspections for smaller projects

Not every project uses every stage. Typical examples:

• Deck: footing (holes dug before concrete), framing (ledger attachment, flashing, joist hangers, and post-to-beam connections, inspected before decking hides them where required), and final with guards and stairs.
• Reroof: often a final only, though some departments inspect sheathing nailing or ice barrier mid-roof, particularly in high-wind regions.
• Water heater or HVAC replacement: usually a single final covering venting, gas connection, combustion air, and electrical.
• Basement finish or interior remodel: rough-ins and framing, insulation, sometimes drywall, and final.
• In-ground pool: commonly a pre-pour inspection of steel and equipotential bonding before concrete or shotcrete, electrical and equipment inspections, and a final that checks the required barrier, gates, and alarms before the pool is filled or used.
• Solar: often a rough or structural check and a final, followed by utility approval before the system can be energized.

How to schedule and pass inspections

• Read the inspection card or permit. It lists the required inspections in order and the rules for requesting them.
• Request inspections in advance. Many departments require notice by a cutoff the day before. Have the permit number and address ready.
• Be truly ready. The work should be complete for that stage. Inspectors frequently fail jobs simply because they were called too early.
• Keep the permit and approved plans on site. IRC R105.7 requires the permit or a copy to stay on the site until the project is complete, and R106.3.1 requires the approved construction documents to be kept at the site and available to the inspector.
• Provide access. Clear paths, ladders for attic or roof access, and locked dogs or gates opened.
• Have documentation available. Manufacturer installation instructions, truss drawings, engineer letters, and test reports are often requested.
• Ask questions. If a correction is unclear, ask the inspector to explain the code section. Inspectors generally prefer to resolve issues on site.

How inspections differ by city

The stages come from the code, but the logistics are local. Examples from official city pages:

• Seattle. SDCI takes requests online or on a 24-hour phone line. Requests made before 7 a.m. are usually inspected the same day; later requests go to the next workday. Inspectors take calls 7 to 8:30 a.m. and 3 to 4:30 p.m., do site inspections 8:30 a.m. to 3 p.m., and do not guarantee arrival times.
• Austin. Inspections are requested through the AB+C portal or by phone with an IVR PIN, permit number, and inspection code. The permit must be active, linked to your account, and fully paid. Inspections usually happen within 24 hours of scheduling but can slip to 48 hours depending on workload.
• Phoenix. The remote video inspection program lets a homeowner or contractor walk an inspector through the work by live video at a scheduled time. It covers limited residential work such as solar main-breaker de-rates, service upgrades up to 200 amps, meter socket replacements, water heaters, minor plumbing and electrical, gas line repairs, and sewer lines. You need a smartphone with front and rear cameras, a 4G or Wi-Fi connection, the Webex app, and tools such as a tape measure, level, flashlight, and ladder.
• Denver. The city’s fee schedule says permit fees cover customary inspections only. Reinspections, after-hours inspections, and non-customary inspections are charged at $100 per hour, and after-hours inspections must be prepaid with a two-hour minimum.

Pre-inspection checklist

• Permit card and approved, stamped plans on site (IRC R105.7, R106.3.1)
• Work for this stage finished; nothing that needs inspection is covered
• Earlier inspections signed off, such as rough-ins before framing (R109.1.4)
• Required tests running or documented: plumbing water or air test, gas pressure test, and energy test reports where required
• Manufacturer installation instructions, truss drawings, and engineer letters available
• Flood elevation documentation ready if the site is in a flood hazard area
• Clear access: ladder for attic or roof, pets secured, gates unlocked, someone present if interior access is needed
• Permit number, address, and inspection code ready when you request the inspection

What not to do

Do not cover work that has not passed inspection. IRC R109.4 says work shall not be done beyond each inspection point without the building official’s approval, and any portion that fails must be corrected and not covered or concealed until authorized. Covering uninspected work can force you to open walls or ceilings, and it can complicate a later sale. See unpermitted work for what happens when work is concealed without approval.

Questions to ask your building department

• Which inspections are required for my permit, and in what order?
• How do I schedule them, and what is the cutoff for next-day inspections?
• Do you offer virtual or video inspections for minor work?
• Are third-party energy tests or engineer letters required?
• What does a reinspection cost?

You can find your local building department for inspection scheduling details.