Category: Construction specialty · Reviewed by Simon Temme, Account Executive · Last reviewed 2026-06-05
Inherent defects insurance, often abbreviated IDI, is the alternative term — used by certain insurers and in certain international contexts — for latent defects insurance covering structural defects in completed buildings that become apparent after practical completion; the substantive product is the same as latent defects insurance.
Category: Construction specialty Also known as: IDI, structural warranty insurance, latent defects insurance First codified: France’s ‘Decennale’ regime (1804 Code Civil); UK voluntary market from c.1980s Related legislation: Defective Premises Act 1972 [1]; Building Safety Act 2022 [2]; Limitation Act 1980 [3]
The terms ‘inherent defects insurance’ (IDI) and ‘latent defects insurance’ (LDI) refer to the same product set in the UK construction insurance market: a long-term first-party insurance covering structural defects in completed buildings that emerge after practical completion. The choice of terminology is principally a matter of insurer or international market preference rather than substantive distinction [4][5].
In UK and Lloyd’s market documentation, ‘latent defects insurance’ is the more common term, particularly for residential warranty products such as NHBC Buildmark and Premier Guarantee. ‘Inherent defects insurance’ is more often used in commercial property and international contexts, particularly where the product is structured around the FIDIC suite of contracts or for projects in jurisdictions influenced by the French Decennale tradition [4][5].
The canonical full treatment of the product structure, legal framework, market practice and claims experience is at /wiki/latent-defects-insurance-construction/. This entry exists for readers searching for ‘inherent defects insurance’ and to disambiguate the alternative terminology [4][5].
The defining features of the product (under either label) are: first-party cover for the building owner (and assignable to successive owners); cover for structural defects emerging within a 10–12 year policy period after practical completion; cover on a ‘no fault’ basis (responding to the existence of the defect rather than to anyone’s fault in causing it); pre-purchased premium calculated as a percentage of reconstruction cost; conditional on technical audit by a Technical Inspection Service; and subrogation against the construction team’s professional indemnity and contractual liability covers [4][5].
The legal framework for inherent defects insurance in the UK is the same as for latent defects insurance:
The Defective Premises Act 1972 (as amended by the Building Safety Act 2022) imposes statutory duties on those involved in providing a dwelling. The 2022 Act extended the limitation period for defective premises claims to 30 years for retrospective claims and 15 years for new claims, making post-completion liability cover materially more relevant [1][2][6].
The Building Safety Act 2022 introduced the new regulatory regime for higher-risk buildings (residential of 18 metres or 7 storeys or more), with substantially heightened post-completion compliance obligations [2][7].
The Limitation Act 1980 sets general statutory limitation periods for contract and tort claims. Section 14A (introduced by the Latent Damage Act 1986) provides a discoverability rule for negligence claims involving latent damage [3][8].
The Misrepresentation Act 1967 and the Insurance Act 2015 apply to the procurement and operation of IDI placements, governing pre-contract disclosure and warranty rules [9].
For international projects, the relevant statutory framework varies by jurisdiction. In France, Belgium, Italy, Spain, the UAE and several other jurisdictions, mandatory decennial liability regimes drive compulsory insurance requirements that the UK IDI market often supports through coordinated wordings [10].
The market practice for inherent defects insurance is described in detail at /wiki/latent-defects-insurance-construction/. In summary:
IDI is arranged by the developer at the start of construction, with cover commencing at practical completion and running for the policy period (typically 10 or 12 years). Pre-purchased premium of 0.3%–1.5% of reconstruction cost is paid at inception [4][5].
The cover is conditional on technical audit by an appointed Technical Inspection Service throughout design and construction. The TIS reports are key conditions of cover [4][5].
In the event of a structural defect emerging during the policy period, the building owner claims under the policy for the costs of repair or reinstatement. The insurer pays the cost and pursues subrogation against the construction team [4][5].
The choice of label (IDI vs LDI) does not affect the substantive cover. Insurer marketing materials and product names vary, but the underlying wording structure and the principal market participants are the same [4][5].
The variations of inherent defects insurance are the same as those for latent defects insurance and are described in detail in that entry:
Residential IDI/LDI: NHBC Buildmark, Premier Guarantee, LABC Warranty and competitive products. Mortgage lender requirements drive market practice.
Commercial IDI/LDI: cover for non-residential developments. Less mature market than residential; specialist insurers and bespoke wordings predominate.
Mixed-use IDI/LDI: integrated cover for mixed-use developments.
Refurbishment IDI/LDI: cover for major refurbishment projects.
Build complete and run-off cover: cover purchased at or shortly after practical completion.
International IDI: cover for UK developers’ international projects, often structured to satisfy local decennial requirements.
A UK developer is completing a £35m commercial office development with an expected reconstruction cost of £42m. Inherent defects insurance is arranged for a 12-year policy period with an inception premium of approximately £210,000 (0.5% of reconstruction cost). The cover is conditional on the TIS approving the design and inspecting construction at key milestones; the development passes the TIS regime and the cover incepts at practical completion. The policy is taken out in the name of the developer with assignment provisions allowing the cover to follow the building to subsequent purchasers. The choice of the ‘inherent defects’ label rather than ‘latent defects’ reflects the insurer’s product marketing; the substantive cover is identical to LDI products in the market. Figures in this example are illustrative.
This entry is part of the Apex Insurance Wiki. Last reviewed by Matt Bartlett on 2026-06-05. Next review: 2026-12-05.
Apex Insurance Brokers Limited. Authorised and regulated by the Financial Conduct Authority, FRN 724952. Registered in England and Wales, Companies House 07014570. This entry provides general information about UK insurance concepts and is not regulated advice. Consult your insurance broker on your specific position.
Apex Insurance Brokers serves UK professional services firms and commercial businesses. Call 0117 325 0027, email hello@apexinsurancebrokers.co.uk, or request a quotation.
Get a quote