If you are buying a new-build home in the UK, the NHBC warranty (officially called Buildmark) is probably the single most important document in your purchase pack – and one of the least understood. Buyers often assume it is a ten-year “anything goes wrong, they fix it” guarantee. It is not. Cover changes sharply after year two, a minimum claim value applies, and a long list of exclusions catches many of the problems buyers actually experience. This 2026 guide explains exactly what the NHBC warranty covers, what it leaves out, how to make a claim, what changed in the 2025 and 2026 policy updates, and why a professional snagging survey from a suitably qualified, accredited surveyor is the best way to protect your position.
The NHBC warranty is Buildmark, a 10-year warranty and insurance policy provided by the National House Building Council for newly built and newly converted homes registered with NHBC. It protects your deposit before completion, obliges the builder to fix defects in years 1–2, and insures specified structural parts of the home against damage from defects in years 3–10. The builder pays the premium; the buyer pays nothing.
NHBC is the UK’s largest provider of new-home warranties and, according to its own website, its warranty and insurance policies currently protect around 1.2 million homes. Buildmark is the mainstream product for homes built for private sale; sister products such as Buildmark Choice cover homes built for rent or social housing. In 2026 the current Buildmark policy (prefix “CC”) applies to plots registered from 1 April 2026, while homes registered in the previous year sit under the 2025 “CB” policy. The structure of cover is the same, but it is worth reading your own policy booklet because the wording and limits are set by the version that applies to your plot.
It is important to understand that Buildmark is not a general guarantee of quality. It is a layered product: a guarantee of the builder’s obligations in the early years, and an insurance policy against specific types of damage later on. The NHBC Buildmark page sets out the headline terms, and the full policy document explains the conditions.
The easiest way to understand the NHBC warranty is to think of it as three separate policies that happen to sit in one booklet.
| Stage | When it applies | Who is responsible | What is covered | Key limits |
|---|---|---|---|---|
| Section 1: Pre-completion | From exchange of contracts (missives in Scotland) to legal completion | NHBC | Loss of deposit, or the extra cost of finishing the home, if the builder becomes insolvent | Typically 10% of the purchase price, up to £100,000; first owner only |
| Section 2: Builder warranty | Years 1–2 after completion | The builder, guaranteed by NHBC | Repair of defects where the home does not meet NHBC Technical Requirements (NHBC Standards) | Builder must fix; NHBC resolution service and guarantee if the builder fails or is insolvent |
| Section 3: NHBC insurance | Years 3–10 after completion | NHBC | Physical damage caused by a defect in specified parts: foundations, load-bearing walls, roofs, chimneys and flues, external render and cladding, windows and doors, stairs, floors and ceilings, double or triple glazing and some below-ground drainage | Total payouts capped at the original purchase price up to £1m (£500,000 for conversions); minimum claim value £1,200 for policies from April 2025 |
During the first two years, your contract is with the builder. If something in the home does not comply with NHBC Technical Requirements – a leaking roof detail, a sticking door caused by a poorly fitted frame, missing insulation, defective brickwork – the builder must put it right. NHBC guarantees that obligation, so if the builder refuses, delays or goes out of business, you can ask NHBC’s Resolution Service to investigate and, where the builder fails to comply, NHBC can carry out or pay for the work itself. This is the most generous phase of the warranty and the one most buyers underuse.
From year three the policy becomes insurance against damage caused by a defect in the listed structural and weatherproofing elements. The distinction matters: a minor defect that has not yet caused damage will generally not trigger a claim, and parts of the home that are not on the list (kitchen units, internal decoration, most plumbing and electrics, boilers, gardens, drives and fences) are not covered at all in this period. NHBC also covers reasonable costs of alternative accommodation and storage if a covered repair makes the home uninhabitable, and certain contaminated-land remediation where a statutory notice applies.
The exclusions are where buyers are most often caught out. Across both periods, and based on the 2026 Buildmark policy summary, the following are outside cover:
Historically the Buildmark minimum claim value rose by £50 every 1 April after the builder warranty period, which meant the threshold a homeowner had to clear kept creeping up over the life of the policy. According to a note on the revised policies published by law firm Devonshires on 3 April 2025, NHBC fixed the MCV as a static figure for all Buildmark and Buildmark Choice policies issued from 1 April 2025, set at £1,200 for the 2025 (“CB”) policy year and applying throughout years 3–10. The same update clarified that insolvency deposit cover is limited to the first owner, tidied up the definition of the “home”, and changed the wording on withheld amounts so that NHBC “may” rather than “will” deduct sums from claims.
The practical effect is simple: if NHBC’s assessed cost of a valid repair meets or exceeds the MCV, NHBC pays in full or carries out the work with no contribution from you; if it falls below the MCV, NHBC pays nothing and does no work. Small structural defects therefore sit with the homeowner in years 3–10, which is a strong argument for getting defects identified and reported in writing before year two ends.
The process depends on which stage of cover you are in. Keep everything in writing, date-stamp photographs, and keep copies of every email and letter: a clear paper trail is what turns a complaint into a successful claim.
Independent evidence makes a difference at every stage. A written defects report from a suitably qualified, accredited surveyor – whether regulated by RICS, CIOB, RPSA or another recognised body – identifies the defect, explains the likely cause and references the relevant NHBC Standard or Building Regulation, which is precisely the information NHBC’s investigators need. Our guide to expert witness evidence in building defects claims explains how formal reports are structured when a dispute escalates.
Because years 1–2 are the only period in which the builder must fix defects of any size, and because cosmetic snags are largely outside cover afterwards, the most valuable thing a new-build buyer can do is commission a professional snagging survey, ideally before legal completion or within the first few weeks of moving in. A surveyor will typically check brickwork and pointing, roof coverings and flashings, render and cladding, window and door installation, insulation and ventilation, plumbing and heating commissioning, electrical fittings, internal finishes and external works, then produce a numbered list the builder can work through.
The scale of the problem is well documented. In September 2026 the New Homes Ombudsman Service (NHOS) published its 2025/26 annual report, reported by Property Industry Eye on 7 September 2026: formal complaints from new-build buyers rose from 593 to 1,802 in a year (up 204%), 82% of decisions went in the homeowner’s favour, compensation awarded rose to almost £215,000, and defects and snagging were the most common complaint issues, with snagging enquiries up 205%. NHOS noted that disputes often escalated not because of the original defect but because of slow responses and poor complaint handling by developers. The scheme now covers more than 65% of new homes sold in the UK, which means around a third of buyers still rely on the older Consumer Code for Home Builders rather than the New Homes Quality Code.
For a practical checklist, read our guides to new-build snagging inspections and how to prepare a snagging list, and our analysis of new-build defects statistics. If you are weighing up whether a survey is worth it at all on a brand-new property, see do you need a survey on a new build?
Yes. Buildmark attaches to the home rather than the owner, so if you sell within the 10-year period the unexpired cover passes to the buyer, less any deductions for claims already paid. Mortgage lenders routinely ask to see the Buildmark certificate for homes under 10 years old, so keep the certificate and policy booklet safe and pass them to your conveyancer when you sell. Note that some elements, in particular pre-completion deposit protection against builder insolvency, are limited to the first owner who contracted with the builder.
NHBC is the largest provider but not the only one. LABC Warranty, Premier Guarantee, Checkmate, Build-Zone, ICW and several others offer broadly similar 10-year structural warranties, usually with a two-year developer defects period followed by structural insurance, and most lenders accept the main providers. The details differ, however: minimum claim values, caps, the list of specified parts, and whether the warranty provider or the developer handles early-year disputes all vary. Ask your conveyancer to confirm the provider, the policy version and the exact limits before you exchange, and check whether the development is registered under the New Homes Quality Code (most large housebuilders since October 2022) or the Consumer Code for Home Builders, because that determines which ombudsman or dispute scheme you can use.
The NHBC warranty is not your only route if a new home turns out to be defective. Under the Defective Premises Act 1972, anyone taking on work in connection with the provision of a dwelling owes a duty to see that the work is done properly and that the home is fit for habitation when completed. Section 135 of the Building Safety Act 2022 extended the limitation period for these claims from 6 years to 15 years for homes completed after 28 June 2022, and to 30 years retrospectively for earlier homes. That means a buyer can, in principle, pursue the developer in court long after the 10-year warranty expires, although litigation is slow, expensive and depends on expert evidence. Our guide to Building Safety Act claims and expert evidence explains how surveyor reports support these cases. You may also have claims under the sale contract itself and, for consumers, under the Consumer Rights Act 2015 in respect of services.
Two developments are worth knowing about. First, NHBC has announced changes to its site inspection regime from 1 August 2026, including a move to risk-based benchmarking of builders, the withdrawal of its TAI platform, changes to drainage testing requirements and an end to fire door lining inspections as a specific stage inspection; NHBC states that its Standards themselves are not changing as part of that package. Second, the industry is expecting a new edition of NHBC Standards (the technical requirements that define a “defect” under Buildmark) with tighter expectations on airtightness, ventilation, moisture risk and fire compartmentation, although at the time of writing NHBC has not confirmed a publication date. Because a defect is measured against the Standards in force when your plot was registered, the edition that applies to your home will not change after the fact, but fewer on-site inspections make an independent snagging survey an even more sensible precaution.
Survey Merchant is a UK building surveying and valuation marketplace that matches you with suitably qualified, accredited surveyors for every stage of a new-build purchase. Here is why buyers use us:
Do not let the builder’s two-year window pass without an independent inspection. Book a snagging survey or defects report today, or contact Survey Merchant for a free, no-obligation quote.
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