A crack appears in the wall of a five-year-old new build. It runs along a load-bearing section, and no snagging inspection could have picked it up when the property was handed over. The fault was there from the start, hidden inside the structure, and it has only just become visible.
This is a latent defect. It is different from the scuffed paintwork or sticking door that gets flagged during a final walkthrough. Latent defects stay hidden until long after completion, sometimes for years, and when they surface the repair bill can be substantial.
This guide explains what a latent defect actually is, what latent defects insurance covers, what the Latent Damage Act 1986 does and does not do, and who ends up paying for cover. If you are a developer, contractor, or property owner trying to work out where your responsibilities start and end, this should give you a clear answer.
What Is a Latent Defect
A latent defect is a fault in the design, materials or workmanship of a building that exists at the point of completion but cannot be found through reasonable inspection at that time. It is hidden within the structure rather than sitting on the surface, and it only becomes apparent once it causes visible damage, sometimes years down the line.
This matters because it changes who can reasonably be blamed and when. Nobody signed off on a building with a known fault. The problem was baked in from the start and nobody could have spotted it without pulling the structure apart.
Latent Defects vs Patent Defects
The easiest way to tell these apart is to ask whether a competent inspector could have found it at handover.
- Patent defects are visible or detectable through normal inspection. Think chipped tiles, a door that will not close properly, or a visible gap in flashing.
- Latent defects are hidden within the structure or its materials. They cannot be found without invasive testing, and they only show themselves once the building has been in use for some time.
Patent defects are usually picked up and fixed during the defects liability period, often the first two years after completion. Latent defects, by definition, are not.
Common Examples of Latent Defects
- Foundation movement caused by poor ground preparation
- Roof truss failure due to a design error
- Waterproofing failure below ground level
- Structural cracking caused by substandard materials
- Corroded reinforcement hidden within concrete
None of these would show up on a standard inspection at completion. That is exactly the problem latent defects insurance is designed to solve.
What Does Latent Defects Insurance Actually Cover
Latent defects insurance, sometimes called inherent defects insurance or structural warranty cover, pays out for the cost of repairing hidden structural faults that appear after completion. It is a first-party policy, which means the person claiming does not need to prove that a contractor was negligent or chase them through the courts. The insurer pays out based on the damage itself, not on who is at fault.
Most policies cover:
- Foundations and load-bearing structure
- Roof structure and covering
- Structural waterproofing
- Resultant damage caused by a covered structural failure
Some more comprehensive policies also cover non-structural elements, such as mechanical and electrical services or lifts, though this varies by insurer and by project.
What is usually excluded:
- Known defects present before the policy started
- General wear and tear
- Damage caused by poor maintenance
- Cosmetic or non-structural snagging issues
Cover is typically arranged at or before practical completion and runs for 8 to 12 years from that date, though longer terms are increasingly available. This length of cover is one of the main reasons latent defects insurance exists in the first place. Legal routes to redress have time limits, and those limits do not always line up neatly with when a defect actually appears.
The Latent Damage Act 1986 Explained Simply
There is a lot of confusion around this piece of legislation, partly because it gets called different things. It is not the “Latent Defects Act.” The correct name is the Latent Damage Act 1986, and it amends the Limitation Act 1980 by adding a new section, 14A, that deals specifically with negligence claims involving latent damage.
Under the standard rules, you generally have six years from the date the damage occurred to bring a negligence claim. The problem is obvious once you think about latent defects: if the damage is not discovered until year eight, that six-year window may have already closed before anyone even knew there was a problem.
The Latent Damage Act 1986 fixes this by giving claimants three years from the date they knew, or reasonably ought to have known, about the defect, whichever is later than the original six-year limit. There is a final backstop though. No claim can be brought more than 15 years after the negligent act or omission that caused the damage, no matter when it was discovered.
So in short:
- Six years from when the damage occurred, or
- Three years from when you discovered it, whichever is later
- Capped at 15 years overall from the original negligent act
Why the Act Alone Is Not Enough
Having a longer window to sue sounds reassuring, but it only helps if there is someone left to sue. A contractor can go out of business long before a latent defect surfaces. Proving negligence in court takes time, costs money, and is never guaranteed to succeed even when the fault is obvious.
This is exactly the gap latent defects insurance fills. Instead of relying on a legal right that depends on tracking down a solvent contractor and proving fault, the policyholder claims directly against the insurer. No blame needs to be established. The building owner gets the repair funded, and the insurer takes on the job of recovering costs elsewhere if it chooses to.
Who Pays for Latent Defects Insurance
In most cases, the developer or main contractor arranges and pays for the policy before the project reaches practical completion. The premium is usually a single upfront payment, though some insurers offer instalment options.
The cost is generally built into the overall project budget rather than billed separately to the eventual owner. Historically, premiums sat around 1.3% to 1.7% of the rebuild cost, though pricing has become more competitive as the market has matured and more insurers now offer this type of cover.
Mortgage lenders are a major driver of demand here. Most UK lenders require latent defects insurance to be in place before they will lend on a new build property, particularly where the building is under 10 years old. Without it, a developer may struggle to sell units at all, since buyers relying on a mortgage simply will not be able to complete the purchase.
Who Actually Needs Latent Defects Insurance
- Developers building new residential or commercial schemes
- Self-builders, particularly where a mortgage or future sale is likely
- Housing associations and registered providers delivering social housing
- Funders and investors who want balance sheet protection against structural risk
Example in Practice
Go back to the crack in the five-year-old wall. If latent defects insurance is in place, the owner submits a claim, an assessor confirms the fault meets the policy definition, and the insurer funds the repair. No court case, no need to track down the original contractor, no argument about who was negligent.
Without a policy, the owner is left relying on the Latent Damage Act 1986. That means proving the defect was caused by negligence, identifying who was responsible, checking whether they are still trading, and potentially pursuing a claim through the courts, all within a limitation window that can be difficult to calculate precisely.
Latent Defects Insurance and the Building Safety Act 2022
Recent regulatory change has extended things further. Under the Building Safety Act 2022, post-completion latent defects cover is now available for up to 15 years from the building’s completion certification date, longer than the traditional 10 to 12 year term. For developers working on larger or higher-risk schemes, this extended period offers more protection and may increasingly become the expected standard rather than the exception.
Getting the Right Cover Sorted Before Practical Completion
The definitions matter, but so does timing. Latent defects insurance needs to be arranged before or at practical completion, not after a problem has already shown up. Once a defect is known about, it cannot usually be covered retrospectively.
For developers, this means treating latent defects insurance as a standard part of project planning, not an afterthought once a lender asks for proof of cover. For self-builders, it means checking whether a future sale or remortgage will require this type of policy, even if it does not feel urgent right now.
Understanding the difference between a latent and a patent defect, knowing what the Latent Damage Act 1986 actually gives you, and having the right insurance in place covers both the legal and financial sides of this risk. If you want tailored advice on arranging cover for your project, you can get a quote from our team.
Frequently Asked Questions
What is the difference between a latent defect and a patent defect?
A patent defect is visible or detectable at completion through normal inspection. A latent defect is hidden and only becomes apparent later, often years after the building is in use.
Does the Latent Damage Act 1986 mean I do not need latent defects insurance?
No. The Act extends the time you have to bring a legal claim, but it does not guarantee there is a solvent party to sue or that negligence can be proven. Insurance provides direct cover without needing to establish fault.
How long does a latent defects insurance policy last?
Most policies run for 8 to 12 years from practical completion, though some now extend to 15 years following changes introduced by the Building Safety Act 2022.
Who is responsible for arranging latent defects insurance?
Usually the developer or main contractor, before the project reaches practical completion. The cost is typically built into the overall project budget.
Is latent defects insurance a legal requirement?
It is not a legal requirement in the strict sense, but most UK mortgage lenders will not lend on a new build without it, which makes it essential in practice for most residential developments.