What Inspections Are Required for a Residential Permit Under IRC 2018?

Quick Answer

IRC 2018 Section R109.1 establishes five types of required inspections: footing, foundation, plumbing, mechanical, electrical, and gas systems (rough-in), frame, and final. Call for each inspection at the correct stage before covering the work. The building official schedules inspections within the timeframe specified by local rules, typically 24 to 48 hours after the request.

What R109.1 Actually Requires

IRC 2018 Section R109.1 identifies the required inspections as follows. R109.1.1 requires a footing inspection to be made after excavation for footings is complete and any required reinforcing steel is in place, but before concrete is poured. R109.1.2 requires a foundation inspection after all anchor bolts are set and before any framing or backfill is done. R109.1.3 requires plumbing, mechanical, gas, and electrical systems to be inspected at the rough-in stage — after all rough-in work is complete but before any part of the work is covered or concealed. R109.1.4 requires a frame inspection after all framing is complete: all fire-blocking and draft-stopping is in place; all concealed wiring, piping, ductwork, and mechanical systems are rough-inspected and approved; and before insulation is installed. R109.1.5 requires a final inspection to be made after work is complete and before the building is occupied. R109.1.6 addresses other inspections: the building official may make or require other inspections to ascertain compliance with this code and other laws enforced by the building official. Notably, R109.2 requires the permit holder to notify the building official when work is ready for inspection. Work that is covered before the required inspection is approved violates R109.3, which prohibits concealment of work before inspection. R109.3 states that it shall be unlawful to conceal work that has not been inspected and approved, and the building official shall require the work to be uncovered at the permit holder's expense.

Some projects require additional inspections beyond the five standard types listed in R109.1. R109.1.6 authorizes the building official to require any other inspection necessary to verify code compliance. In practice, these additional inspections may include: a plywood or structural sheathing inspection for projects using engineered shear wall panels; an insulation inspection to verify that insulation is installed before drywall but after framing approval; a pre-slab plumbing inspection for slab-on-grade construction; a special inspection for high-strength concrete or structural steel; and an energy compliance inspection in jurisdictions that have adopted that requirement. Building departments also commonly require a sewer and water lateral inspection by the public works department, which is separate from the plumbing rough-in inspection performed under the building permit. The general contractor must coordinate all required inspections -- both building code inspections and utility inspections -- and ensure all are approved before calling for the final building inspection.

Why This Rule Exists

Inspections exist because residential construction involves hidden work that cannot be verified after the fact without destructive testing. Once drywall covers framing, insulation conceals vapor barriers, and concrete encases footings, defects become inaccessible. The sequential inspection protocol in R109.1 is designed to catch errors at the earliest possible stage — before the cost of correction escalates. Footing inspections prevent under-designed foundations from being buried. Rough-in inspections catch improper wire sizing, drain slope errors, and duct leakage before walls are closed. Frame inspections verify that structural members are correctly sized, notched, and connected. Final inspections confirm that the completed building is safe to occupy. The inspection record also creates a permanent paper trail that protects future owners and establishes code compliance for insurance and financing purposes.

What the Inspector Checks at Rough and Final

At the footing inspection, the inspector verifies: excavation depth per R403.1.4 frost depth requirements; footing dimensions per R403.1 tables; rebar size, spacing, and coverage; and that soil bearing capacity assumptions are reasonable. At the foundation inspection: anchor bolt spacing (maximum 6 feet for sill plates per R403.1.6), bolt diameter (minimum 1/2 inch), and embedment depth. At rough-in (mechanical, electrical, plumbing, gas): electrical wire sizing, outlet box fill, AFCI and GFCI protection locations; plumbing drain slope (1/4 inch per foot per P3005.3), vent sizing, and trap configurations; mechanical duct sizing, combustion air provisions, and venting terminations; gas pipe sizing, pressure testing, and sediment trap locations. At frame inspection: joist, rafter, and header sizes per Chapters 5 and 8 span tables; fire-blocking at wall top plates, floor/wall intersections, and concealed spaces per R302.11; stair framing and guardrail blocking. At final: smoke alarms per R314 (battery backup, location in each sleeping room and on each floor); CO alarms per R315; egress window dimensions per R310; GFCI protection per E3902; stair dimensions per R311; handrails per R311.7.8.

What Contractors Need to Know

Contractors must build inspection scheduling into their project timeline. Missing a required inspection stage — particularly covering framing or rough-in work before inspection — can result in a mandatory open-wall order that destroys finished work and delays the project significantly. Most building departments require inspection requests to be submitted 24 to 48 hours in advance; some high-volume departments require 72 hours or more. Contractors should confirm the local lead time at permit issuance. The sequence matters: the frame inspection cannot be called until rough-in inspections have been completed and approved. Inspectors will typically sign off a frame inspection only if they have approved rough-in cards in hand or in the permit folder. For larger projects with multiple subcontractors, the general contractor must coordinate each trade's rough-in work so all trades are ready simultaneously for the rough-in visit. It is the permit holder's responsibility under R109.2 to notify the building official — the inspection does not happen automatically. Contractors who leave permit card notification to the homeowner risk delays when the homeowner forgets to call.

Contractors should also understand how reinspection fees work in their jurisdiction. When an inspection is failed -- meaning the inspector issues a correction notice identifying code-deficient work -- a reinspection is required after the corrections are made. Most jurisdictions charge a reinspection fee, typically $75 to $150, for each reinspection visit after the first failed attempt. On projects with multiple inspection stages, repeated failures at the same stage can add significant cost. The most effective way to avoid reinspection fees is to have the work actually complete and correct before requesting the inspection. Contractors who call for inspections before trade subcontractors have finished their work -- hoping to get an early check-in from the inspector -- typically end up paying reinspection fees when the inspector identifies incomplete or non-compliant items. Calling for an inspection should only happen when the work for that stage is completely finished and verified by the contractor.

What Homeowners Get Wrong

Homeowners acting as their own general contractors frequently underestimate the inspection sequence and call for inspections out of order. A common mistake is requesting a final inspection before all rough-in inspections have been approved, resulting in a failed final and the need for a reinspection fee. Another frequent error is covering framing — installing insulation or drywall — before the frame inspection is approved. Inspectors will fail the frame inspection and issue a correction notice requiring the covering to be removed. Some homeowners believe that if the contractor does the work correctly, the inspection is just a formality that can be skipped. This is incorrect: the inspection is a legal prerequisite to occupancy under R110, and skipping it creates an unpermitted condition that must be resolved before the property can be sold or refinanced. Forum questions frequently ask whether a partial final is acceptable when some rooms are not complete. IRC 2018 R109.1.5 requires all work to be complete before the final inspection — partial finals are a local discretionary practice, not a code requirement, and not all jurisdictions allow them.

Owner-builders managing their own inspection schedule for the first time are particularly prone to calling for inspections in the wrong sequence. The most consequential sequence error is calling for the frame inspection before rough-in inspections are approved. Inspectors conducting a frame inspection expect to see all rough-in work complete and previously approved -- meaning electrical rough-in, plumbing rough-in, and mechanical rough-in inspections have each been separately called for, inspected, and signed off. If any of those inspections has not been performed yet, the frame inspection will be failed and a reinspection fee will be charged after the missing rough-in inspections are completed. Owner-builders should post the inspection sequence in a visible location on the job site and check off each stage as it is approved. Many building departments provide an inspection record card with the permit package that serves this purpose.

State and Local Amendments

States enforcing IRC 2018 — including Texas, Georgia, Virginia, North Carolina, South Carolina, Tennessee, Alabama, Mississippi, Kentucky, and Missouri — typically adopt R109.1 without major amendments but vary widely in administrative implementation. Texas municipalities generally follow the R109.1 inspection sequence but use third-party inspection firms in many jurisdictions. Georgia requires special inspections for certain structural elements under ASTM standards incorporated by reference. Virginia's Uniform Statewide Building Code adds inspection requirements for energy code compliance. In IRC 2021, Section R109.1 was updated to add explicit provisions for energy inspections, including blower door testing for air leakage per R402.4.1.2. IRC 2018 states do not have the same mandatory blower door requirements built into R109.1, though they may have adopted energy code amendments independently. The 2021 edition also clarified the rough-in inspection triggering conditions for combination inspections.

When to Hire a Licensed Contractor

The inspection process itself does not require a licensed contractor — homeowners can serve as owner-builder and manage inspections. However, consistently passing inspections requires work that meets code, which is more reliably achieved by licensed tradespeople. Licensed electrical, plumbing, and mechanical contractors in IRC 2018 states are familiar with the local inspection requirements and the common items inspectors check. For structural work — footing, foundation, and framing — a licensed general contractor with local experience will know what inspectors look for. If work fails inspection, a licensed contractor is best positioned to make the required corrections quickly. Hiring licensed tradespeople reduces the risk of failed inspections and associated reinspection fees.

Common Violations Found at Inspection

• Framing covered with drywall before the frame inspection was approved, requiring opening of walls at the permit holder's expense.
• Footing concrete poured before footing inspection, requiring core samples or partial excavation to verify compliance.
• Rough-in electrical work covered before inspection; improper AFCI protection for bedroom circuits.
• Plumbing drain installed without inspection; improper slope and missing cleanout at the base of the stack.
• Smoke alarms missing in required locations: not in each sleeping room, not on each floor, and not within 21 feet of cooking appliances per R314.
• Egress window in basement bedroom does not meet R310 minimum opening dimensions of 5.7 sq ft, 24-inch height, and 20-inch width.
• Carbon monoxide alarm absent in dwelling with attached garage or fuel-burning appliances per R315.
• Final called before rough-in inspections approved; inspector unable to issue certificate of occupancy.