The Defects Liability Period: A Homeowner's Guide to Post-Completion Protection

Introduction

Practical completion is a significant milestone in any building project — it marks the point at which the contractor hands over the completed works to the homeowner and the homeowner takes occupation. But practical completion is not the end of the contractor's obligations. The defects liability period (DLP) — typically 6 or 12 months following practical completion — is a defined period during which the contractor is required to return to site to remedy defects that emerge in the completed works. Understanding the DLP, and managing it actively, is one of the most important responsibilities in the post-completion phase of a project. This guide explains how the DLP works in domestic building contracts. For related guidance, see our handover checklist, JCT contracts guide and final account guide.

What Is the Defects Liability Period?

Under a JCT building contract (and most other standard form domestic building contracts), the defects liability period (also called the "rectification period" in JCT terminology) is the period following practical completion during which:

• The homeowner can identify and notify defects — faults, shrinkage, and other deficiencies in the works
• The contractor is obliged to return to site and make good those defects at no additional cost to the homeowner
• Half of the retention sum is released to the contractor — the other half is held until the end of the DLP

The standard DLP in JCT Minor Works (the most commonly used domestic building contract) is 3 months, though this can and should be extended to 6 or 12 months by agreement at contract stage. See our JCT contracts guide.

What Counts as a Defect?

A defect under the building contract is any fault, shrinkage, or other deficiency in the works that:

• Is due to materials or workmanship not in accordance with the contract requirements (drawings, specification, building regulations)
• Arises from frost damage where the works were not adequately protected

A defect is NOT:

• Damage caused by the homeowner or their other contractors after practical completion
• Wear and tear from normal use
• New work outside the original scope (variations needed after practical completion)
• Issues arising from the homeowner's own specification choices (e.g. a floor finish that scratches easily — if the specification was the homeowner's choice, the contractor is not liable for its performance)

How to Document and Notify Defects

Effective management of the DLP requires a systematic approach to identifying and notifying defects:

1. Snagging inspection at practical completion: At the point of practical completion, the architect and homeowner carry out a snagging inspection — a detailed walk-through of the completed works noting all outstanding items. These are typically minor — incomplete finishes, adjustment of ironmongery, touching-up paintwork. Significant incomplete work should prevent practical completion from being certified. See our handover checklist.
2. Ongoing defects log during DLP: As the building settles and is occupied through its first winter season, defects emerge — cracking in plaster as the building dries out, door adjustments needed as the structure moves slightly, external sealants failing. Maintain a written log of all defects as they appear.
3. Formal defects notification: Near the end of the DLP, the architect issues a formal defects schedule to the contractor — a comprehensive list of all outstanding defects requiring remedy. The contractor must then return and remedy all items within a reasonable period.

End of DLP: Making Good and Retention Release

At the end of the DLP, once the architect is satisfied that all notified defects have been made good:

• The architect issues a "Making Good" certificate confirming that the contractor's obligations under the DLP have been discharged
• The final half of the retention is then released to the contractor
• The contractor's liability for defects under the contract (arising from the DLP notification process) ends — though liability for latent defects under common law continues for a longer period (6 years under simple contract, 12 years under a deed)

What Happens If the Contractor Refuses to Return?

If the contractor fails to remedy notified defects within the DLP, the homeowner's remedies are:

• Withhold the final retention until defects are remedied
• Engage another contractor to remedy the defects and deduct the reasonable cost from the retention sum
• Pursue a claim against the contractor for the cost of remediation if retention is insufficient to cover the cost

An architect who actively manages the DLP — issuing formal defects schedules, following up on contractor attendance, and certifying making-good — provides the homeowner with the documented record necessary to pursue any of these remedies. See our post-completion guide.

Conclusion

The defects liability period is one of the most important protections a building contract provides — but it only protects the homeowner if it is actively managed. Documenting defects as they appear, issuing formal notifications, and managing the contractor's return to remedy outstanding items all require professional oversight. An architect appointed for the full project service, including post-completion administration, provides this oversight as part of the appointment. Use our free matching service to find an architect who actively manages the full project lifecycle in NW3. For cost guidance, visit hampsteadrenovationcosts.co.uk.