How to Maintain Your New Build Warranty Coverage

Your new build warranty is one of the most valuable protections that comes with purchasing a newly constructed home in the UK. Covering structural defects for up to 10 years and a wide range of other issues during the initial builder warranty period, it provides a financial safety net that can be worth tens of thousands of pounds if a serious problem arises. Yet many homeowners fail to fully understand their warranty, miss critical reporting deadlines, or unknowingly take actions that compromise their cover. This comprehensive guide explains exactly how new build warranties work, what each period covers, how to report defects correctly, what actions can invalidate your warranty, and — most importantly — how to maintain your coverage so it is there when you need it.

Every new build home sold in the UK must come with a warranty or insurance policy that protects the buyer against defects. This is a requirement of the mortgage lending industry — virtually all mortgage lenders require a new build warranty as a condition of lending. The warranty is provided by a warranty provider (a specialist insurance company), and the cost is paid by the developer as part of the build process. The most common warranty providers in the UK are NHBC (which provides the Buildmark warranty and covers approximately 70–80% of all new homes), LABC Warranty, Premier Guarantee (now part of MD Insurance Services), and Checkmate. While the detail varies between providers, the basic structure is similar: an initial period where the builder is responsible for fixing defects, followed by a longer period of structural insurance.

10 Years

Total Warranty Duration

70–80%

UK Homes Covered by NHBC

£0

Cost to Homeowner (Developer Pays)

Understanding the Warranty Structure

New build warranties in the UK are structured in two main phases. Understanding what each phase covers — and crucially, what it does not cover — is essential for knowing when and how to make a claim.

Phase 1: Builder Warranty Period (Years 1–2)

During the first two years after legal completion, the builder (developer) is directly responsible for fixing defects in your home. This period is sometimes called the “defects liability period” or “builder warranty period.” It covers the widest range of issues, including cosmetic defects, faulty materials, poor workmanship, non-functioning systems (heating, plumbing, electrics), and items that do not meet the specification you were promised. The builder’s obligation is to put right any defects that arise from their failure to build to the warranty provider’s technical standards or the building regulations.

During this period, your first point of contact for any defect should be the builder directly. Most developers have a dedicated aftercare or customer service team that handles snagging and defect reports. If the builder fails to address your concerns within a reasonable timeframe, you can escalate to the warranty provider, who can intervene on your behalf. Under the NHBC Buildmark policy, if the builder refuses or fails to fix a defect that they are responsible for, NHBC can use its Resolution Service to investigate and, if necessary, require the builder to act or arrange the repair itself.

Phase 2: Structural Insurance Period (Years 3–10)

From year 3 onwards, the warranty transitions from a builder obligation to an insurance policy provided by the warranty company. This insurance covers structural defects only — defined as defects in the structure of the home that cause physical damage or an imminent danger to the health and safety of the occupants. The definition of “structure” typically includes foundations, walls, floors, roofs, load-bearing elements, external render, external cladding, flues and chimneys, and sometimes drainage below the building footprint.

It is crucial to understand that the structural insurance period does NOT cover cosmetic issues, minor defects, wear and tear, condensation, mould (unless caused by a structural defect), appliances, fixtures and fittings, soft landscaping, boundary fences, or any defect that does not affect the structural integrity or habitability of the home. This narrower scope catches many homeowners by surprise, particularly when issues that seemed minor during years 1–2 develop into more significant problems during years 3–10 but do not meet the “structural defect” threshold.

Year 0 — Pre-Completion

Warranty provider inspects the build at key stages. NHBC conducts an average of 5–6 inspections per house. These inspections check compliance with technical standards and building regulations. Any issues identified must be resolved before completion.

Years 1–2 — Builder Warranty (Defects Liability)

Covered: All defects arising from non-compliance with warranty standards — structural, cosmetic, mechanical, electrical. Contact: Builder’s aftercare team first, then warranty provider if unresolved. Key action: Report all defects in writing within this period, especially before the year 2 deadline.

Years 3–10 — Structural Warranty (Insurance)

Covered: Structural defects causing physical damage or danger. Foundations, walls, floors, roofs, load-bearing elements, external cladding. Contact: Warranty provider directly. Key action: Document any structural issues with photos, dates, and professional assessments.

Year 10+ — Warranty Expires

No further warranty cover. Any defects must be remedied at your own expense. Some structural issues may be covered by the Limitation Act (6 years for breach of contract, 15 years for deed) — seek legal advice if you believe the builder was negligent.

Warranty Providers Compared

While all UK new build warranty providers offer broadly similar coverage, there are differences in the detail, claims process, and customer experience. Here is a comparison of the four major providers.

Feature	NHBC Buildmark	LABC Warranty	Premier Guarantee	Checkmate
Market Share	~75%	~10%	~10%	~5%
Builder Period	2 years	2 years	2 years	2 years
Structural Period	Years 3–10	Years 3–10	Years 3–10	Years 3–10
Max Claim Value	Purchase price or index-linked	Purchase price	Purchase price	Purchase price
Resolution Service	Yes (free)	Yes	Yes	Yes
Contaminated Land Cover	Yes	Yes	Yes	Limited
Accepted by Lenders	All lenders	Most lenders	Most lenders	Some lenders

How to Report Defects Correctly

Reporting defects correctly is one of the most important things you can do to protect your warranty coverage. A defect that is reported in writing during the warranty period creates a formal record that can be relied upon even if the repair takes months to complete. Conversely, a defect that is only mentioned verbally, or is noticed during the warranty period but not formally reported until after it expires, may not be covered.

Document the Defect

Take clear photographs showing the defect from multiple angles. Note the date the defect was first observed, its location in the home (room, wall, floor level), and a description of the problem. If the defect is recurring (e.g., damp patch that appears after rain), note the pattern and any weather conditions.

Report in Writing

Send a written report to the builder’s aftercare team (during years 1–2) or directly to the warranty provider (years 3–10). Email is acceptable and provides a dated record. Include your address, warranty/policy number, description of the defect, photographs, and when you first noticed the issue. Always keep copies of all correspondence.

Follow Up and Record

If the builder does not respond within 14 days, send a follow-up in writing. Keep a log of all communications — dates, names, reference numbers, what was agreed. If the builder sends a contractor to inspect, note their name and company, and ask for a written report of their findings.

Escalate If Needed

If the builder fails to act within 56 days (NHBC standard), escalate to the warranty provider’s resolution service. Provide copies of all correspondence showing that you reported the defect and that the builder has failed to respond adequately. The warranty provider will investigate and can require the builder to carry out repairs.

Critical Deadline Warning

The end of year 2 is the most important deadline in your warranty. After this date, the builder’s obligation ends and only structural defects are covered. If you have been aware of any defect — no matter how minor it seems — report it in writing before the end of year 2. This creates a formal record that the defect existed during the builder warranty period, which significantly strengthens your position even if the repair is not completed until after year 2.

What Is Covered — and What Is Not

Understanding the boundaries of your warranty coverage helps you set realistic expectations and avoid disappointment. Here is a detailed breakdown of what is typically covered and excluded under a standard new build warranty.

Covered (Years 1–2)

✓ Structural defects (foundations, walls, roof)
✓ Defective workmanship (poor plastering, tiling, etc.)
✓ Faulty materials used in construction
✓ Plumbing and heating system defects
✓ Electrical installation defects
✓ Windows and doors not functioning properly
✓ Water ingress through the building envelope
✓ Drainage defects within the building curtilage

NOT Covered

✗ Normal wear and tear
✗ Shrinkage cracks (normal in new builds)
✗ Condensation and mould (unless structural cause)
✗ Appliances (boiler, oven, hob — manufacturer warranty)
✗ Garden landscaping, fencing, turfing
✗ Damage caused by homeowner alterations
✗ Cosmetic issues after year 2
✗ Damage from natural events (flooding, storms)

What Can Invalidate Your Warranty

Perhaps the most critical section of this guide: understanding what actions can invalidate or reduce your warranty coverage. Taking any of the following steps without proper precautions could leave you without protection when you need it most.

⚠

Structural Alterations Without Notification

Removing load-bearing walls, altering foundations, extending the property, or making changes to the roof structure without notifying your warranty provider can invalidate cover for the affected area. Always contact your warranty provider before any structural work and get written confirmation that your planned works will not affect coverage.

⚠

Poor Maintenance of the Property

Warranty providers expect homeowners to maintain their property to a reasonable standard. Failure to keep gutters clear, not addressing a small leak that worsens over time, allowing vegetation to damage the structure, or blocking ventilation openings can all be used as grounds to reduce or refuse a warranty claim. The argument is that the damage was caused or worsened by your failure to maintain, not by a defect in the original construction.

⚠

Non-Compliant DIY or Trades Work

DIY electrical work, plumbing alterations not signed off by a competent persons scheme (like NICEIC or Gas Safe), or building work carried out without building regulations approval can invalidate warranty coverage for the affected systems. Always use qualified, certified tradespeople and obtain appropriate certificates for all work.

⚠

Failing to Report Defects Promptly

If you notice a defect but do not report it, and the defect worsens over time, the warranty provider may argue that the additional damage was caused by your failure to mitigate. Report all defects as soon as you notice them, even if they seem minor. Early reporting also creates a paper trail that protects your interests.

⚠

Change of Use

Using the property for a purpose other than its intended use (e.g., converting it to an HMO, running a business that generates heavy foot traffic, or making the property available for short-term holiday lets without appropriate insurance) may affect your warranty. Always check with your warranty provider if you are planning a change of use.

Essential Record-Keeping

Good record-keeping is your strongest protection for maintaining warranty coverage. If a dispute arises about whether a defect was reported, when it first appeared, or what the builder agreed to do about it, having clear, dated records can make the difference between a successful claim and a rejection.

Your Warranty File: What to Keep

📄 Warranty policy document — the full policy booklet from your warranty provider
📄 Certificate of insurance — the formal certificate confirming your cover
📄 Completion/handover documents — from the developer, including any specifications
📄 Snagging list and responses — the original snagging report and all follow-up
📄 Defect reports — all written reports of defects, with dates and photos
📄 Correspondence — all emails and letters to/from builder and warranty provider
📄 Photographs — dated photos of all reported defects and completed repairs
📄 Boiler/appliance manuals — including registration and service records
📄 Building regulations certificates — for any alterations you have made
📄 Maintenance records — boiler servicing, gutter cleaning, any upkeep work

Digital Backup Tip

Create a digital copy of your entire warranty file and store it in cloud storage (Google Drive, Dropbox, iCloud). Take photos of paper documents, scan certificates, and save all email correspondence in a dedicated folder. If your physical files are lost, damaged, or destroyed, the digital backup will protect your interests. Label files clearly with dates for easy reference.

Maintenance Schedule to Protect Your Warranty

Proactive maintenance not only keeps your home in good condition but also demonstrates to the warranty provider that you have fulfilled your obligation to maintain the property. Here is a recommended maintenance schedule for new build homeowners, organised by frequency.

Frequency	Task	Why It Matters for Warranty
Monthly	Check for visible leaks, damp patches, condensation	Early reporting of water ingress protects your claim
Monthly	Open trickle vents and ensure ventilation is working	Blocked vents cause condensation — not covered by warranty
Quarterly	Check external drainage gullies and clear debris	Blocked drains causing flooding could be seen as negligence
Quarterly	Test smoke alarms and CO detectors	Safety compliance; non-functioning alarms are a serious issue
Twice Yearly	Clean and inspect gutters and downpipes	Overflowing gutters cause water damage — maintenance failure
Twice Yearly	Inspect exterior for cracks, gaps in render or pointing	External defects worsen quickly if not reported
Annually	Service the boiler (Gas Safe engineer)	Protects boiler manufacturer warranty and demonstrates maintenance
Annually	Check external sealant (around windows, doors, cladding)	Failed sealant is a common defect route — report if deteriorating
Annually	Inspect roof tiles from ground level (binoculars)	Slipped or missing tiles allow water ingress — report immediately

Making a Warranty Claim: Step by Step

If you need to make a warranty claim, following the correct procedure maximises your chances of a successful outcome. Here is a step-by-step guide for both the builder warranty period and the structural insurance period.

Years 1–2 Claims Process

1. Report to builder’s aftercare team in writing
2. Builder has 28 days for non-urgent defects
3. If no response, send a formal follow-up letter
4. If still unresolved after 56 days, escalate to warranty provider’s resolution service
5. Warranty provider investigates and may direct builder to act
6. If builder refuses or has ceased trading, warranty provider arranges repair directly
7. Keep copies of everything at every stage

Years 3–10 Claims Process

1. Contact warranty provider directly (not the builder)
2. Complete a claim form and submit with photographs and description
3. Warranty provider appoints a surveyor to inspect
4. Surveyor produces a report assessing whether the defect is structural and covered
5. If approved, warranty provider arranges and pays for repairs
6. If rejected, you can appeal or seek independent legal advice
7. Independent survey evidence strengthens an appeal

What If the Builder Has Gone Into Administration?

One of the key benefits of a new build warranty is that it provides protection even if the builder ceases trading, goes into administration, or is liquidated. During the builder warranty period (years 1–2), if the builder is unable to fulfil their defect repair obligations, the warranty provider steps in directly. They will arrange for the defect to be assessed and, if it falls within the warranty terms, will arrange and pay for the repair work using their own approved contractors.

This protection is particularly valuable in the current economic climate, where construction company insolvencies are at elevated levels. If your builder goes into administration, contact your warranty provider immediately. Do not attempt to commission your own repairs without first consulting the warranty provider, as doing so may compromise your coverage. The warranty provider will need to assess the defect and determine whether it is covered before authorising any work.

Protected

Even If Builder Goes Bust

Full Purchase Price

Maximum Claim Value (Typically)

Common Defects to Watch For

Knowing what to look for helps you identify defects early and report them within the critical year 2 deadline. Here are the most common defects found in new build homes, ranked by frequency of occurrence based on warranty provider data and snagging company reports.

Defect	Frequency	Warranty Period	Action
Shrinkage cracks in plaster/walls	Very Common	Years 1–2	Report if widening or structural
Doors sticking or not closing properly	Very Common	Years 1–2	Report — builder should adjust
Window/door seal failures	Common	Years 1–2	Report — affects energy and weather
Plumbing leaks or dripping taps	Common	Years 1–2	Report immediately — water damage risk
Poor external drainage	Common	Years 1–10	Report — may be structural if beneath building
Roof tile displacement	Moderate	Years 1–10	Report promptly — water ingress risk
Render cracking or delamination	Moderate	Years 1–10	Report — potential structural issue
Foundation movement/subsidence	Rare but Serious	Years 1–10	Report urgently — major structural claim

Selling a Home with an Active Warranty

When you sell your new build home, the warranty transfers automatically to the new owner. This is a significant selling point, as buyers are reassured by the remaining warranty coverage. To ensure a smooth transfer, make sure you provide the buyer with the original warranty certificate and policy document, details of any claims made and their outcome, records of any defects reported (even if resolved), and evidence of ongoing maintenance.

Most warranty providers do not require formal notification when a property changes hands — the policy is linked to the property, not the owner. However, it is good practice for the new owner to contact the warranty provider to confirm their details and obtain a copy of the policy if needed. If you have made any structural alterations to the property, ensure you have documented the warranty provider’s written confirmation that the works do not affect coverage, as this will be important for the new owner.

Selling Tip

A property with several years of remaining warranty coverage and a well-documented maintenance history commands a premium compared to one where the warranty has expired or records are incomplete. When marketing your home, highlight the remaining warranty period and the fact that you have comprehensive records. This reassures buyers and their solicitors, potentially speeding up the sale process.

If Your Warranty Claim Is Rejected

If your warranty claim is rejected, you have the right to challenge the decision. Start by requesting a written explanation of why the claim was rejected, including specific reference to the policy terms that the warranty provider relies on. Review the explanation carefully against your policy document to check whether the rejection is justified.

If you believe the rejection is wrong, you can appeal through the warranty provider’s internal complaints procedure. If the internal complaint does not resolve the matter, you can escalate to the Financial Ombudsman Service (FOS), which has jurisdiction over warranty claims as they are insurance products. The FOS can investigate your complaint free of charge and make a binding decision that the warranty provider must comply with. For claims involving significant sums, you may also want to take independent legal advice from a solicitor specialising in construction law or housing defects.

Obtaining an independent survey from a chartered surveyor (RICS member) can significantly strengthen your case when challenging a rejected claim. The surveyor can provide a professional assessment of the defect, its cause, and whether it falls within the scope of the warranty. This independent evidence carries significant weight in both internal appeals and FOS complaints.

£0

Cost to Complain to FOS

£300–£800

Independent Survey Cost

8 weeks

Max Wait for Internal Complaint Response

Summary: Your Warranty Maintenance Checklist

Protecting your new build warranty requires ongoing attention, not just at the point of purchase. Here is a summary checklist to keep your coverage intact throughout the full 10-year period.

10-Year Warranty Protection Checklist

☑ Store your warranty documents safely (physical + digital backup)
☑ Report ALL defects in writing with photographs and dates
☑ Complete a thorough check before the year 2 deadline
☑ Follow the regular maintenance schedule
☑ Service your boiler annually with a Gas Safe engineer
☑ Clean gutters and check drainage at least twice a year
☑ Notify your warranty provider before any structural alterations
☑ Use qualified, certified tradespeople for all work
☑ Keep building regulations certificates for any alterations
☑ Never block ventilation openings or trickle vents
☑ Keep a communications log with dates, names, and outcomes
☑ Know how to escalate: builder → warranty provider → FOS

Your new build warranty is a valuable asset that provides financial protection against the unexpected. By understanding how it works, reporting defects promptly and correctly, maintaining your home to a reasonable standard, and keeping comprehensive records, you can ensure that this protection remains fully available to you for the entire 10-year duration. The small investment of time required for regular maintenance and record-keeping is insignificant compared to the potential cost of a major structural repair that a well-maintained warranty could cover. Take control of your warranty from day one, and it will be there for you when you need it most.