Who Is Responsible If Subcontracted Work Fails or Causes Damage in NZ?

When building work goes wrong in New Zealand, working out who is responsible can feel complicated — especially when multiple tradespeople are involved. The short answer is that the main contractor generally holds primary responsibility to you as the homeowner, but the picture can involve the subcontractor, their insurer, and even licensing bodies depending on the situation.

How the Main Contractor–Subcontractor Relationship Works

When you hire a builder or building company to manage your project, you enter into a contract with that main contractor (also called the head contractor or principal contractor). They take on the job of coordinating the work, which often means bringing in subcontractors — specialist tradespeople such as electricians, plumbers, roofers, or tilers.

Critically, you typically have no direct contract with those subcontractors. Your legal relationship is with the main contractor. This means:

• If a subcontractor's work is defective or causes damage, your first point of call is the main contractor.
• The main contractor is responsible for ensuring all subcontracted work meets the required standard.
• The main contractor may then pursue the subcontractor separately — but that is their problem to sort out, not yours.

The Building Act and Licensed Building Practitioners

New Zealand's Building Act 2004 and the NZ Building Code set minimum standards that all building work must meet. Under this framework, Licensed Building Practitioners (LBPs) are legally required to carry out or supervise certain types of restricted building work — things like structural work, weathertightness, and fire safety systems.

If restricted building work is done incorrectly, the LBP who carried it out (or supervised it) can be held accountable through the Licensed Building Practitioners scheme. You can make a complaint to the LBP Registrar if you believe a licensed practitioner has done defective work or breached their duties. This applies whether they were the main contractor or a subcontractor.

Restricted Trades: Electrical, Plumbing, and Gas

Some subcontracted work is legally restricted to licensed professionals regardless of who hired them:

• Electrical work must be carried out by a registered electrician and inspected/certified. The Electrical Workers Registration Board (EWRB) oversees this.
• Plumbing, gasfitting, and drainlaying must be done by a licensed tradesperson registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB).

If unlicensed work in these areas causes damage or injury, liability can become very serious — and insurance may not cover it. Always confirm that any subcontractor doing restricted work holds a current licence.

What Happens When Things Go Wrong

Here is a general guide to how responsibility typically plays out:

Important: If you directly hire a subcontractor yourself — bypassing the main contractor — you take on the contractual relationship with them directly. This can complicate your position if something goes wrong.

Insurance: A Critical Layer of Protection

A reputable main contractor should carry public liability insurance and, ideally, contract works insurance. Subcontractors should also hold their own public liability cover. Before work starts, ask your main contractor:

• Do you hold current public liability insurance?
• Are your subcontractors insured?
• Is there contract works insurance in place for this project?

If a subcontractor causes damage and has no insurance, recovering costs can be very difficult. BRANZ provides useful guidance on building quality and what to expect from building professionals.

Building Consents and Inspections

For work that requires a building consent, the local council's building inspectors will check that work meets the NZ Building Code at key stages. Consent-required work that fails inspections must be remedied before a Code Compliance Certificate (CCC) is issued. The MBIE Building Performance website explains what work requires consent and what falls under Schedule 1 exemptions — though you should always confirm with your local council, as requirements can vary.

Protecting Yourself Before Work Starts

• Get everything in writing — a clear, signed contract with the main contractor that specifies who is responsible for subcontracted work.
• Check LBP registration at lbp.govt.nz before work begins.
• Verify licences for any electrical or plumbing subcontractors.
• Ask for proof of insurance from the main contractor.
• Keep records — photos, emails, invoices, and inspection reports.

When to Call a Professional

If subcontracted work has already failed or caused damage, consider:

1. Contacting the main contractor in writing first, outlining the defect and requesting remedy.
2. Making a complaint to the LBP Registrar if restricted building work is involved.
3. Contacting the EWRB or PGDB if electrical or plumbing work is at fault.
4. Seeking legal advice if the contractor is unresponsive or disputes liability — a construction lawyer or Consumer NZ can help clarify your options.

For your next project, finding a qualified, insured local builder through tradedirectory.co.nz is a great starting point to reduce the risk of these issues arising in the first place.

Sources & Further Reading

• MBIE Building Performance – NZ Building Code and consents
• Licensed Building Practitioners – Check registration and make complaints
• BRANZ – Building research and quality guidance
• Plumbers, Gasfitters and Drainlayers Board
• Electrical Workers Registration Board
• Consumer NZ – Disputes and your rights