By Adam Hicks, CooperBuild AI · November 10, 2026

The construction warranty period most GCs talk about is the one-year window after substantial completion when you have to come back and fix work that doesn't meet the contract. That one-year correction period is real, but it usually isn't the end of your warranty exposure, and equipment and special warranties can run on their own clocks. The best way to close it out cleanly is an 11-month warranty walk with the owner, documented and tracked to sign-off.

This guide covers when the clock starts, what the one year actually means, how to run the 11-month walk, and how to keep warranty callbacks from eating your margin. If you're still finishing the job, start with our guides to substantial vs final completion and construction closeout documents.

#When does the construction warranty period start?

On most commercial jobs the warranty clock starts at substantial completion, the date the owner can use the building for its intended purpose. Many standard-form general conditions say warranties begin on that date unless the certificate of substantial completion says otherwise.

Not everything starts on the same day, though:

• Phased turnover. If the owner takes a floor or building early, the warranty for that portion may start when it's substantially complete, not at the end of the whole job.
• Work finished after substantial completion. Items completed later (punch work, seasonal landscaping, a backordered unit) often get a correction period that's extended to match.
• Manufacturer and equipment warranties. These can start at shipment, installation or startup. A rooftop unit set in month four of an 18-month job may have burned a big chunk of its warranty before the owner moves in.
• Residential builder warranties. On new homes the clock often runs from closing or first occupancy, and many builders use a tiered 1-year, 2-year and 10-year structure for workmanship, systems and structure.

Write the actual start date for every warranty on your closeout log. "One year from completion" isn't specific enough when there are five different completion dates on one project.

#Is the one-year warranty really just one year?

Usually not. Most contracts have two separate things that get lumped together as "the warranty":

1. The contractor's warranty that the work is new, good quality and meets the contract documents.
2. The one-year correction period, an obligation to come back and fix nonconforming work the owner reports within a year.

Construction attorneys point out that under common industry forms, the one-year correction period limits how long you have to come back and repair the work, not how long you can be held liable for it. After the year, an owner may still be able to make a breach-of-warranty claim for money, within the state's statute of limitations or statute of repose. Miller Nash (opens in a new tab) and Much Shelist (opens in a new tab) both walk through this.

For example, the widely used AIA A201 general conditions set a one-year correction period after substantial completion and say it doesn't limit the contractor's other obligations. AIA and the document names are trademarks of The American Institute of Architects; CooperBuild AI isn't affiliated with or endorsed by AIA.

The practical takeaway: don't close the file on day 366. Keep warranty records and as-builts for as long as your attorney says your exposure lasts in that state.

#What is an 11-month warranty walk?

An 11-month warranty walk is a joint walkthrough with the owner, roughly a month before the one-year correction period ends, to find and document anything that needs fixing while it's still clearly inside the window.

Owners and home inspectors already know about it. Homeowner forums are full of "we did our 11-month inspection and the builder won't respond" threads, and owner-side PMs on r/Construction ask how to get the GC to show up for an end-of-warranty walk. If you schedule it yourself, you control the list, the timeline and the tone.

Why GCs should push for it:

• One list instead of a year of random calls. You fix things in one mobilization instead of ten.
• Clear end date. A signed-off walk is your best evidence that the correction period ended clean.
• Owner relationship. Showing up before you're chased is how you get the next job and the reference.

#How do you run a warranty walk?

Here's a simple process that works on commercial and residential jobs.

#1. Schedule it at month 10

Send the owner a date in month 10 or early month 11. That leaves time to fix items and still meet the notice deadline. Invite the subs with the most likely callbacks: roofing, mechanical, plumbing, doors and hardware, flooring and sealants.

#2. Pull the warranty file before you go

Bring the closeout log with every warranty's start and end date, the O&M manuals, prior service calls and the original punch list. Items that were "fixed" at punch and came back are the first ones to check.

#3. Walk it like a punch list

For each item record the location, what you saw, a photo, the responsible trade and whether it's covered. An item without a location gets a callback; an item without a photo gets a second visit. Our punch list guide uses the same format.

#4. Sort what's covered from what isn't

Be fair and be clear. Typical exclusions are owner maintenance (filters, caulk upkeep, clogged gutters), damage from the owner's own changes or use, and normal shrinkage or settlement within the contract's tolerances. Put excluded items in writing with the reason, and offer to price them as extra work if the owner wants them done.

#5. Assign, schedule and close each item

Send each sub their items in writing with a date. Track every item to done with a photo, and get the owner's sign-off on the completed list. Keep the signed list with the project's closeout file.

#Who pays for warranty work?

Under most contracts, the GC is responsible to the owner for warranty corrections, and the subs are responsible to the GC for their own scope through matching warranty language in their subcontracts. That flow-down is what keeps the cost off your books.

A few things that help:

• Match your sub warranties to your prime. If your prime warranty starts at substantial completion and your roofer's starts at their completion date, you can end up carrying months of exposure alone.
• Don't let anyone else fix covered items first. Many warranties give the warrantor the right to inspect and repair. An owner or third party who repairs first can create a fight about who pays.
• Track warranty cost by job. Callbacks that never hit a job cost report hide which trades, details or crews cause problems. A small cost code for warranty labor and materials makes that visible. See our job costing guide.
• Know your retainage terms. Some contracts tie part of final payment to closeout documents and warranty letters, so a missing warranty can hold real money. More in our retainage guide.

#How do you keep warranty callbacks under control?

Most warranty pain starts long before turnover. A few habits make the one-year period quieter:

• Collect warranties at submittals. Put warranty terms and start conditions on the submittal log so nothing surprises you at closeout.
• Log startup and commissioning dates. That's when many equipment warranties actually start.
• Give the owner a short warranty contact sheet at turnover: who to call for what, how to report an issue in writing, and what counts as an emergency.
• Require written notice. A text to the super isn't a warranty claim. A dated email or form with photos is, and it protects both sides.
• Review callbacks after every job. If the same detail fails on three projects, it's a design or install problem, not bad luck.

#How CooperBuild AI fits

CooperBuild AI keeps the project, its change orders, billing and job costs in one place, with built-in accounting (general ledger, payables and receivables), a QuickBooks Online connection if that's where your books live, and online payments through Stripe. When an owner or sub mentions a leak or a warranty item in the job chat, it can be picked up as an action item for review, so it gets assigned instead of buried in the thread.

If you want your next warranty year to end with a signed list instead of a surprise call, get started with free credits, no credit card needed.

#FAQ

#How long is the construction warranty period?

On many commercial contracts the contractor has a one-year correction period that starts at substantial completion, plus longer manufacturer or special warranties on items like roofing and equipment. Residential builder warranties often use a 1-year, 2-year and 10-year structure. Your contract sets the actual terms.

#When does a contractor's warranty start?

It usually starts at substantial completion unless the contract or the certificate of substantial completion sets a different date. Phased turnovers, work finished after substantial completion and equipment warranties can each start on their own date.

#Does the one-year warranty end the contractor's liability?

Usually not. The one-year correction period typically limits how long the contractor must come back and repair the work, while breach-of-warranty claims may still be brought within the state's statute of limitations or repose. Ask a construction attorney about your state.

#What is an 11-month warranty walk?

It's a joint walkthrough with the owner about a month before the one-year correction period ends, to document defects with locations and photos, assign them to the responsible trades and close them out while they're still inside the warranty window.

#Who pays for warranty repairs in construction?

The general contractor is usually responsible to the owner, and subcontractors are responsible to the GC for their own scope through warranty terms in their subcontracts. Excluded items like owner maintenance or owner damage are usually the owner's cost.

This article is general information for contractors, not legal advice. Confirm warranty terms, start dates and notice requirements in your contracts, and talk to a construction attorney about limitation periods in your state.