What is the defects liability period in construction?

The period after practical completion when the contractor must return to put right defects that appear. JCT calls it the rectification period, and NEC4 deals with defects up to the defects date. The length is set in the contract. Check your contract and take advice if what's covered is disputed.

Can AI identify defects from photos?

It can describe what's visible in a clear photo, such as a chipped tile or a gap in a sealant joint. It can't see behind finishes, measure tolerances or judge the work against the specification, and it can be confidently wrong. Use it to write up what you found, not to find it.

How do you write a good snag?

Say where it is, what's wrong and what done looks like: "Bedroom 2, door to landing, catches on the frame at the head, adjust to close freely." Add the trade, a photo reference and a target date. Vague items like "paint touch-ups" get argued about and come back.

Who pays for remedial works after handover?

Usually the contractor puts right defects in its own work during the defects period at no extra cost to the client, and passes them to the subcontractor responsible. Damage the client causes, or changes they ask for, are different. Check your contract and take advice.

AI for Snagging & Defects

Generate snagging lists, defect reports, and remedial works schedules using AI-powered templates.

Jump to:3 workflows How AI helps FAQs

3 AI workflows for snagging & defects

🔍

Generate a Snagging List Template

Create a detailed room-by-room snagging checklist tailored to a specific building type for systematic defect identificat...

Beginner

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✅

Generate a Quality Inspection Checklist

Create a detailed quality inspection checklist tailored to a specific trade or building element.

Beginner

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📊

Create a Project Closeout Report

Generate a comprehensive project closeout report covering programme, cost, quality, safety performance, and key learning...

Intermediate

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How AI helps with snagging & defects

AI helps with snagging by turning walk-round notes and photos into a clean, numbered list with locations, trades and target dates. Before the walk round, it can build a room-by-room checklist for the building type, so every inspector follows the same route. After handover, the same approach turns a client's complaint and your inspection notes into a defect report or a remedial works schedule.

What it can't do is inspect the work. It doesn't know whether a crack is cosmetic or structural, whether a finish meets the specification, or which trade really caused the problem. Those calls belong to the site manager, and completion is for whoever the contract names as certifier.

Start with one job, such as next week's walk round on a single floor or plot. Use a business account with data controls switched on, not a personal one, and check every item against what you saw before the list goes out.

Where AI helps most

Snagging checklists: a room-by-room list for the building type, covering finishes, doors, fixtures, services and external areas.
Walk-round notes: voice notes and scribbles turned into numbered snags, each with a location, description, responsible trade and target date.
Lists by trade: one long list split into a list for each subcontractor, so each gets only their own items.
Defect reports: the problem, location, date reported and what's needed, from your notes and photos.
Remedial works schedules: outstanding items grouped by area and trade, in an order that stops the decorator coming back before the joiner has finished.
Close-out tracking: a weekly summary of what's open, closed and overdue.

Where to be careful

Judgement: AI can describe a defect but can't tell you whether it's acceptable. That's judged against the specification and agreed benchmarks, by the site manager.
Contract: whether an item is a snag, a defect the contractor must put right, or a change the client now wants depends on the contract and the facts. Check your contract and take advice.
Safety: fire stopping, fire doors, compartmentation and anything structural need checking by competent people. A list can remind you to look. It can't sign anything off.
Accuracy and data: AI can mislabel rooms or merge two snags into one. Check the list against the drawings, and keep photos from occupied homes inside a business account.

Frequently asked questions

What is the defects liability period in construction?: The period after practical completion when the contractor must return to put right defects that appear. JCT calls it the rectification period, and NEC4 deals with defects up to the defects date. The length is set in the contract. Check your contract and take advice if what's covered is disputed.
Can AI identify defects from photos?: It can describe what's visible in a clear photo, such as a chipped tile or a gap in a sealant joint. It can't see behind finishes, measure tolerances or judge the work against the specification, and it can be confidently wrong. Use it to write up what you found, not to find it.
How do you write a good snag?: Say where it is, what's wrong and what done looks like: "Bedroom 2, door to landing, catches on the frame at the head, adjust to close freely." Add the trade, a photo reference and a target date. Vague items like "paint touch-ups" get argued about and come back.
Who pays for remedial works after handover?: Usually the contractor puts right defects in its own work during the defects period at no extra cost to the client, and passes them to the subcontractor responsible. Damage the client causes, or changes they ask for, are different. Check your contract and take advice.

Related resources

Construction Snagging List: Free Template, Examples, and How to Snag Faster with AIGuide

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