The construction warranty period starts the day after substantial completion and runs for one year on most commercial projects — longer for specific systems (roofing, glazing, mechanical equipment, foundation work). Whether that warranty period goes smoothly for the GC or sub depends almost entirely on how well warranty obligations were documented at closeout and how the warranty-claim workflow is structured. This is a working guide on construction warranty management: the distinction between manufacturer and workmanship warranties, the warranty-claim workflow, the GC-sub-owner handoff chain, and the recurring failures that turn the warranty period into an expensive parking lot.
If you're a GC PM who's gotten the warranty assignment three months after the project closed out — or a sub PM getting a warranty call about work you did 14 months ago and don't remember the details of — you know how easily this workflow falls apart. The warranty period is technically defined and contractually bounded but operationally chaotic at most firms. This post is on what good warranty management actually looks like.
What construction warranty actually is
A construction warranty is a contractual promise that the work performed will be free from defects for a specified period after substantial completion. Two categories matter:
Workmanship warranty is the contractor's promise that the work was performed correctly. Industry standard is 1 year from substantial completion for general workmanship; specific scopes have longer periods (commonly 2 years for mechanical, 5 years for roofing, 10 years for structural). The contractor's obligation under workmanship warranty: remediate defects in their work at no additional cost.
Manufacturer warranty is the equipment or material manufacturer's promise about their product. Periods vary widely: 1 year on commodity items, 25+ years on roofing membranes, 50 years on some structural products. The manufacturer's obligation: replace or repair defective product per the warranty terms (sometimes including labor, often not).
The two warranty types overlap operationally. A leaking roof under year 1 of a 20-year manufacturer roofing warranty might be: a manufacturer issue (defective membrane, manufacturer pays for replacement product), a workmanship issue (correct membrane installed incorrectly, sub pays for re-installation), or both. The investigation and dispute resolution determine which.
The contract documents the full warranty terms for each project. AIA A201 (the General Conditions of the Contract for Construction) has standard warranty language; project-specific contracts amend it for owner-specific requirements.
The warranty-claim lifecycle
Every warranty claim goes through roughly this lifecycle:
- Owner identifies a defect. Building tenant or facilities team notices a problem and reports it to the owner's facilities team.
- Owner notice to GC. Owner submits a warranty claim to the GC within the warranty period (the exact notice mechanism is contract-specific).
- GC investigation. GC's warranty manager (or PM, depending on firm structure) investigates: is it actually a defect, is it under warranty, which sub is responsible, what's the recommended remediation.
- GC routes to sub. If a specific sub's work is responsible, GC notifies sub with the claim details and required remediation.
- Sub investigation. Sub investigates from their side: do they agree the defect is in their scope, is it under their workmanship warranty, can a manufacturer warranty cover it.
- Remediation. Sub performs the corrective work. If equipment replacement is needed, the manufacturer warranty kicks in (manufacturer provides product, sub installs).
- Owner verification. Owner verifies the remediation is complete and the defect is resolved.
- Claim closure. Documentation captured; warranty record updated; if the work was performed under the warranty period, the warranty for that specific remediation often extends a year from completion of the corrective work (terms vary).
The lifecycle works smoothly when the documentation, the responsibility attribution, and the warranty period are all clear. It breaks down when any of those are ambiguous — which is most of the time on most projects.
The closeout binder dependency
Warranty management depends almost entirely on what's in the closeout binder. Specifically:
- Manufacturer warranty registrations — the actual warranty certificates from each manufacturer, with effective dates, serial numbers / model numbers, and registration in the owner's name
- Sub workmanship warranty letters — per scope, with effective dates and warranty period terms
- As-built drawings — showing what was actually installed, not what was originally specified
- Equipment cut sheets and O&M manuals — for diagnosing whether an issue is operating-condition vs equipment-defect
- Sub contact information — including warranty contacts who may differ from project contacts
- Photo documentation of installations — for resolving disputes about what condition existed at substantial completion
If the closeout binder is incomplete — missing warranty certificates, missing as-builts, missing manufacturer registrations — warranty management becomes guesswork. This is why continuous closeout binder assembly matters: the cost of incomplete closeout shows up most expensively during the warranty period.
The recurring warranty failure modes
1. Warranty period started but project staff dispersed. The GC PM who knew the project closed out at substantial completion. They moved to the next job. When a warranty claim arrives 4 months later, the new warranty manager has no project context, no relationships with the subs, and limited closeout-binder material to work from.
2. Manufacturer warranty registrations missed. Many manufacturer warranties require registration within 30-60 days of installation to be valid. If the GC didn't register at closeout (or worse, registered in the GC's name instead of the owner's name), the owner has no manufacturer warranty when they need it. The cost falls to the GC.
3. Sub disputes responsibility with no documentation. Owner reports a leak. GC investigates and attributes to the roofing sub. Roofing sub investigates and says "the leak is from a penetration installed by the MEP sub, not from our roof." Without contemporaneous documentation of the penetration installation, the dispute drags out. The owner sees the leak continuing while the contractors argue.
4. Same defect appearing on multiple buildings. The same window system on three of the GC's projects all start leaking at month 9. Each project handles its claim in isolation. The GC doesn't recognize the pattern (and the systemic root cause — maybe a manufacturer batch defect) until much later. Earlier pattern recognition would have allowed a single coordinated remediation.
5. Owner-side maintenance failures classified as warranty claims. Owner's facilities team didn't change the HVAC filters per the O&M manual; the unit fails; owner files a warranty claim. Contractor or manufacturer is asked to cover what's actually owner-caused. The dispute about classification consumes weeks while the equipment sits broken.
6. Warranty extension on corrective work not tracked. Sub remediates a defect in month 6 of the warranty period. The corrective work has its own warranty (typically 1 year from corrective-work completion). The new warranty period isn't tracked anywhere. When the same defect reoccurs at month 14 (beyond the original project warranty), nobody knows the sub still has obligation on that specific remediation.
7. Latent defects discovered after warranty period. A defect that wasn't visible during the 1-year warranty period surfaces in year 2 or 3. Latent defects are typically covered by separate provisions in the contract (or by state statutes of limitations for construction defects), but enforcement requires documentation that the defect was latent, not just unreported.
What good warranty management looks like
The principles:
Warranty record per project, populated at closeout. The closeout binder warranty section is structured: manufacturer warranties registered with the owner, sub workmanship letters captured, warranty periods clearly noted per scope. This is the operational baseline for the warranty period.
Dedicated warranty manager role. A specific person at the GC owns warranty management across all the GC's active warranty periods (typically projects in years 1-2 post-substantial-completion). The role doesn't have to be full-time at smaller firms but does need to be a clear assignment, not "whoever has bandwidth."
Structured claim intake. Owner warranty claims arrive through a defined channel (email address, portal, phone, depending on firm convention) and get logged with structured fields: project, building system, alleged defect, date reported, owner contact. Email-only intake without structured capture loses claims and prevents pattern recognition.
Sub notification with full context. When a claim routes to a sub, it includes: the original closeout binder data for the relevant scope (their warranty letter, the manufacturer warranty, the as-built drawing), photo documentation if relevant, and a clear deadline for response. The sub doesn't have to re-establish project context from scratch.
Manufacturer warranty engagement from day one. For claims involving equipment under manufacturer warranty, the GC's warranty manager engages the manufacturer directly — either to coordinate with the sub's remediation or to handle the warranty replacement directly with the owner. Delegating entirely to the sub often produces slower resolution.
Pattern detection across projects. The GC's warranty manager reviews claims across active warranty periods (typically all projects in years 1-2) monthly to spot patterns. The same window system failing on three projects triggers a coordinated investigation, not three isolated ones.
Corrective-work warranty tracking. When a sub remediates a defect, the corrective work's warranty period is captured in the warranty record. Future claims on the same remediation can reference the corrective-work warranty even after the original project warranty has expired.
Owner-side maintenance documentation. Claims that may be owner-caused require the GC to document the difference. If the owner didn't follow the O&M manual's maintenance schedule, the GC's warranty manager pulls the O&M and notes the discrepancy in the claim record — not to blame the owner but to clarify warranty vs maintenance.
How AOS handles warranty management cross-tenant
In AOS, warranty is an extension of the closeout binder, with cross-tenant workflow between the GC and the subs. Specifically:
- Warranty records populated at closeout. Per-scope sub warranty letters and manufacturer warranty registrations attach to the closeout binder during project execution (covered in our closeout binder post). When warranty period starts, the records are already in place.
- Warranty period clock per scope. Each warranty (project workmanship, scope-specific extended warranty, each manufacturer warranty) has its own clock. The GC's warranty dashboard shows what's currently under warranty across all active projects, by scope, by date, by sub responsibility.
- Claim intake workflow. Owner submits a claim via portal (or by email, captured into the structured claim record). Claim is logged with project, building system, alleged defect, photo evidence, owner contact.
- Automated sub routing. Claim auto-routes to the responsible sub based on the project's subcontract scope structure. If multiple subs could be responsible, GC's warranty manager confirms attribution before sub notification.
- Sub notification with full context. Sub receives the claim with their original warranty letter, the manufacturer warranty (if applicable), the as-built drawing for that scope, and any relevant photo documentation from project execution. They can investigate without re-establishing context.
- Manufacturer warranty engagement. For equipment claims, the manufacturer warranty record drives the engagement workflow — whether the manufacturer handles replacement directly or coordinates with the sub.
- Pattern detection. The GC's warranty dashboard surfaces patterns across active warranty periods: same system failing on multiple projects, same sub generating disproportionate claim volume, same manufacturer producing pattern defects.
- Corrective-work warranty tracking. When a remediation completes, the corrective-work warranty period starts automatically per the contract terms. Future claims on the same remediation reference the corrective-work warranty.
- Cross-tenant when both sides are on AOS. Sub sees warranty claims in their own dashboard cross-tenant, with full project context. Status updates flow back to the GC and to the owner in real time.
The GC PM role page covers the GC-side workflow. The sub PM role page covers the sub-side workflow. For the closeout dependencies that make warranty management possible, see the closeout binder continuous-assembly post. For the broader strategic story on what changes when both sides are on the platform, see the both-sides-on-one-record post.
The warranty readiness checklist
- Is your closeout binder warranty section structured and complete at substantial completion, or assembled retroactively?
- Are manufacturer warranty registrations done in the owner's name within the required registration window?
- Do you have a dedicated warranty manager role with clear ownership across active warranty periods?
- When a warranty claim arrives, can it be logged with structured fields and auto-routed to the responsible sub?
- Does the sub receive the claim with their original warranty letter, as-built drawing, and project context?
- Are you reviewing claims across active warranty periods monthly to spot patterns?
- Are corrective-work warranty periods tracked, with claims beyond the original project warranty still flagged against the corrective-work warranty?
If most answers are "informally, with workarounds," that's the workflow a connected platform replaces.
If you'd like to see it
We're in private-beta design-partner mode for commercial subs and GCs. If you'd like to walk through how AOS handles warranty management on your active projects — particularly if you have closed-out projects currently in their warranty period — apply to the beta. The GC overview covers the platform broadly.