What Is a Defects Liability Period?

What Is a Defects Liability Period?

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If you have ever signed a building contract or received a quotation from a contractor for a significant home improvement project, you may have come across the term Defects Liability Period. It is one of the most misunderstood concepts in residential construction — and understanding it properly matters for every homeowner commissioning building work.

What Is a Defects Liability Period?

A Defects Liability Period (DLP) is the contractual period that runs after practical completion — the point at which the works are substantially finished and you take possession of the property — during which the contractor is obliged to return and make good any defects that emerge.

The DLP exists because not all defects are visible at the point of practical completion. Some only become apparent with time: hairline cracks caused by settlement, moisture ingress that appears during the first wet winter, or minor fitting issues that only show up under the conditions of normal use. The DLP gives the contractor the opportunity to return and fix these issues before their final payment is released.

How Long Is a Defects Liability Period?

For residential building works, six months is the standard DLP under JCT Minor Works contracts and similar residential building agreements. For larger or more complex works, twelve months is common, giving a full seasonal cycle to identify any latent issues.

What the Retention Mechanism Looks Like

The DLP is commercially underpinned by a retention mechanism. Under a standard JCT-style contract:

• During the works: typically 5% of each interim payment is withheld as retention
• At practical completion: the retention reduces to 2.5% (half is released)
• At the end of the DLP: the remaining 2.5% is released, provided a final defects schedule has been agreed and the contractor has made good all identified defects

This means the contractor has a financial incentive to return and resolve any issues — the retention funds remain the client's until that obligation is fulfilled.

What Counts as a Defect?

A defect, in contractual terms, is workmanship or materials that do not comply with the specification in the contract. This includes:

• Work that does not match the drawings or scope of works
• Materials that are lower specification than what was contracted
• Latent defects — those not apparent at practical completion but arising from the contractor's work during the build period (for example, plasterwork that develops cracks because of poor substrate preparation, or tiling that lifts because of inadequate adhesive)

What Does NOT Count as a Defect

It is equally important to understand what falls outside the DLP obligation:

• Fair wear and tear — normal deterioration associated with use is not a defect
• Client-caused damage — if you damage the contractor's work after practical completion, that is not their responsibility to fix under the DLP
• Problems caused by client-supplied materials — if you supplied materials that failed, the contractor is not liable for the failure
• Problems arising from the client's own design decisions — if the contractor built what was specified and the specification was the client's own choice, the defect in design is not the contractor's to fix

What Happens After the DLP Ends?

The contractor's contractual obligation under the building agreement ends when the DLP expires and the defects schedule has been agreed. However, this does not mean your legal rights end there.

Under the Limitation Act 1980, a client can bring a claim for latent defects in common law:

• 6 years from the date of practical completion for a contract executed under hand (a simple signed contract)
• 12 years from the date of practical completion for a contract executed as a deed

So even if the contractor refuses to return after the DLP, or if a latent defect emerges several years later, you may still have a legal remedy — though pursuing it becomes a matter of litigation rather than a straightforward contract mechanism.

What to Do If the Contractor Refuses to Return During the DLP

If a contractor refuses to return to fix defects during the DLP, you have options:

1. Use the retention. You are entitled to withhold the outstanding retention funds and commission another contractor to fix the defects. The cost should not exceed the retention, but if it does, you can pursue the balance.
2. Small Claims Court. For disputes under £10,000, the Small Claims track in the County Court is a practical and relatively straightforward option.
3. County Court. For larger sums, the County Court is the route.

It is worth noting that the local authority can also serve notice about dangerous structures under the Building Act 1984 — this is a separate statutory regime from your contractual DLP rights, but relevant if the defect is structural in nature.

The RCB Commitment After Completion

At RCB Design & Build, we stand behind our work. Our standard Defects Liability Period for residential projects is six months from practical completion, during which we return to address any genuine defects arising from our workmanship. We manage this as part of our post-completion relationship with clients — not as an adversarial process, but as the professional follow-through that good construction practice demands.

If you are about to commission a significant building project in London, make sure your contract is clear on the DLP duration, the retention percentage, and the process for raising and resolving defects. We are happy to walk you through what to expect before you sign.