New Build Warranty and Defects 2026 — Complete BTL Landlord Guide to NHBC Buildmark

NHBC Buildmark — the 2-year and 10-year warranty structure

NHBC Buildmark is a structural warranty product with two distinct periods:

• Year 1-2 — builder's warranty and NHBC support: In the first 2 years from legal completion, the developer (builder) is responsible for rectifying defects reported by the owner. The definition of a 'defect' in this period is broadly interpreted: it covers workmanship defects (cracked render; poorly fitted windows; inadequate pointing; uneven floors); material defects (substandard insulation; incorrect grade of timber); water ingress through the building envelope; failure of roof coverings; plumbing or drainage defects arising from incorrect installation. If the developer refuses to carry out repairs or is insolvent, NHBC steps in to remedy the defect or compensate the homeowner (subject to NHBC's own assessment of whether the defect meets the Buildmark claim criteria). For BTL landlords: document all defects in writing to the developer within the 2-year period. Keep copies of all correspondence. Defects notified in writing to the developer before the 2-year period expires are preserved even if repair is not completed within the period
• Year 3-10 — structural warranty (NHBC as insurer): From year 3 to year 10 after legal completion, NHBC provides insurance coverage for major structural defects only — not cosmetic defects, not wear and tear, not tenant-caused damage. Major structural defects in this period include: subsidence or heave of the structure; structural failure of load-bearing elements (walls; floors; roof structure); significant water ingress through the structure causing structural damage; failure of drainage systems built into the structure. To make a claim in years 3-10, the defect must: (a) arise from NHBC's Standards being breached during construction; (b) be a major or structural defect (not cosmetic); (c) be reported to NHBC in writing. NHBC investigates and either carries out repairs, arranges for repairs, or pays compensation (subject to the policy excess and the original purchase price cap)
• What NHBC Buildmark does NOT cover: Important exclusions that BTL landlords must understand: (a) Cosmetic defects after the 2-year period — scratched surfaces, minor cracks in plaster (hairline cracks as property settles), uneven paint finish, misaligned doors from normal settlement are not covered in years 3-10; (b) Normal settlement — new properties settle in their first year or two; minor movement cracks in non-structural elements are normal and not a NHBC structural defect; (c) Wear and tear — carpets, kitchen appliances, bathrooms deteriorating through normal use; (d) Tenant-caused damage — deliberate or accidental damage by tenants; (e) Condensation — unless caused by a structural defect (e.g., inadequate insulation causing interstitial condensation in walls). Landlords must maintain the property properly; failure to maintain can void the structural warranty for damage arising from that failure
• NHBC claim limit — original purchase price: NHBC Buildmark coverage is linked to the original purchase price of the property (at first registration). If the cost of remediation exceeds the original purchase price (unusual except in catastrophic cases), the NHBC coverage is capped. For BTL landlords who buy new-build at a significant premium (over-inflated new-build pricing is common), the warranty coverage is capped at the price you paid — not the current value of the property

Building Safety Act 2022 — Defective Premises Act 1972 extension to 15 years

The Building Safety Act 2022 (BSA 2022) made major changes to the rights of homeowners and landlords against developers:

• DPA 1972 s.1 duty — who is owed the duty: Section 1 of the Defective Premises Act 1972 imposes a duty on anyone who takes on work for or in connection with the provision of a dwelling to ensure the work is done in a workmanlike manner, with proper materials, so that the dwelling will be fit for habitation when completed. This duty is owed to both the person ordering the work (first purchaser from developer) AND any person acquiring an interest in the dwelling (subsequent purchasers, including BTL landlords). A BTL landlord who buys a new-build property from the original purchaser has DPA 1972 rights against the original developer — even though the BTL landlord had no contractual relationship with the developer
• Extended limitation period — 15 years for new dwellings (from June 2022): Before the BSA 2022, claims under DPA 1972 had to be brought within 6 years of the date the dwelling was completed (accrual on completion). BSA 2022 extended this to 15 years for dwellings completed on or after 30 June 2022. This means: a BTL landlord buying a new-build completed in January 2026 can bring a DPA 1972 claim against the developer until January 2041. The 15-year period significantly increases the window for pursuing developers for latent defects that only manifest years after completion (e.g., slowly progressing structural failures; water ingress that becomes apparent after several years of weathering)
• Retrospective extension to 30 years for pre-June 2022 dwellings: For dwellings completed before 30 June 2022, BSA 2022 controversially extended the limitation period retrospectively to 30 years. This means: claims that would previously have been time-barred (because more than 6 years had elapsed since completion) may now be revived — subject to the BSA 2022 transition provisions. This retrospective extension is significant for BTL landlords with older new-build properties who discover latent structural defects. Legal advice should be sought immediately on discovery of such defects
• New Homes Ombudsman Service (NHOS) — consumer redress for new homes: The Building Safety Act 2022 established the New Homes Ombudsman Service as a consumer redress scheme for purchasers of new homes. NHOS handles complaints about new home builders registered with the NHOS. Key features: (a) Free for homeowners to use; (b) Can investigate complaints about the quality of the new home, the builder's behaviour, and the aftercare service; (c) Can award up to £50,000 compensation; (d) Developers must be registered with an ombudsman scheme — most major housebuilders are NHOS members. NHOS is separate from NHBC — NHOS handles customer service and quality complaints; NHBC handles structural warranty claims

Snagging, pre-completion inspection, and practical landlord steps

Proactive steps at purchase to preserve warranty rights and protect investment:

• Snagging inspection before legal completion: A professional independent snagging inspection carried out before legal completion (or immediately after completion and before moving tenants in) is the single most valuable step a new-build BTL landlord can take. A snagging surveyor will identify: (a) cosmetic defects (scratches; paintwork deficiencies; poorly fitted fixtures; gaps in skirting; misaligned cabinetry); (b) functional defects (windows and doors not sealing correctly; taps and showers not working; electrical sockets not functioning; heating system faults); (c) structural concerns (visible cracks; inadequate roof ventilation; surface water pooling). All snagging items should be reported to the developer in writing before completion if possible (developers may dispute their liability if defects are reported after the keys are handed over). The developer cannot legally withhold keys pending resolution of snagging items — but they are contractually required to remedy them under the 2-year warranty
• Documenting defects during the 2-year warranty period: During the 2-year builder's warranty period, BTL landlords should maintain a defects log (with photographs, dates, and description of each defect). All reports to the developer should be made in writing (email with read receipt; recorded post). Verbal reports to site managers do not preserve warranty rights in the same way. When tenants report defects during the 2-year period, the landlord should assess whether the defect is: (a) a builder's defect (report to developer under Buildmark warranty); (b) tenant-caused damage (claim against tenant's deposit); (c) fair wear and tear (landlord's maintenance obligation). The distinction is not always obvious — photographs taken at the start of the tenancy (inventory photographs) are essential evidence
• Developer insolvency — what happens to the warranty: If the developer becomes insolvent during the 2-year warranty period, NHBC steps in as insurer-of-last-resort under the Buildmark policy. The BTL landlord (or original purchaser) makes a claim directly to NHBC. NHBC appoints its own contractor to carry out the remediation works. For years 3-10 structural warranty claims, the claim is against NHBC directly (not the developer) — developer insolvency does not affect years 3-10 coverage. Alternative warranty providers (Premier Guarantee; LABC Warranty) have similar insurance structures — check the specific policy wording for each
• Alternative warranty providers — when NHBC Buildmark is not available: Not all new build properties are covered by NHBC Buildmark. Self-builds, conversion projects, and some smaller developers may use alternative warranty providers: (a) Premier Guarantee (now part of Build-Zone): similar 2+10 year structure; (b) LABC Warranty (Local Authority Building Control Warranty): backed by local authority building control inspection; (c) BLP Insurance: specialist warranty for conversions and extensions; (d) Build Assure; (e) MD Insurance. Mortgage lenders typically accept warranties from all major providers — check the specific lender's approved warranty list before exchange of contracts on a new-build property with a non-NHBC warranty. Some lenders (particularly for BTL) have a shorter approved warranty list than for owner-occupier mortgages

Frequently asked questions