NZS 3910 vs NZS 3916 — Which Contract Form Is Right for Your Project?

What is the fundamental difference between NZS 3910 and NZS 3916?

The answer is design ownership.

Under NZS 3910:2023, the Principal holds the design. The Contractor's obligation is to build what the Principal's design says, to the quality the specifications require. If the design is wrong or incomplete, that is the Principal's problem. The Contractor builds to the information it is given, and if that information is late or incorrect, the Contractor is entitled to claim for the consequences.

Under NZS 3916:2025, the Contractor holds the design. The Principal provides a set of requirements — what it wants the finished asset to do, to what standard, within what envelope. The Contractor then designs and builds the solution. If the Contractor's design is wrong, that is the Contractor's problem. The Principal's Requirements define the target. How the Contractor hits it is up to the Contractor.

This single distinction cascades through every other aspect of how these contracts work: who carries latent risk, how variations are assessed, what insurance is needed, how the certifying roles operate, and what happens when something goes wrong.

NZS 3910 accounts for approximately 80% of NZ construction contracts by value. NZS 3916 is used on approximately 10–15% of contracts by value, but that share is growing, particularly in the health, education, and government infrastructure sectors.

When is NZS 3910 the right choice?

NZS 3910 is the right contract form when the Principal has a complete, coordinated design ready for construction tender. It is the dominant form in NZ for a reason: it is well understood, widely used across both building and civil works, and backed by decades of case law and administrative practice.

Choose NZS 3910 when:

• Your design is substantially complete before going to market. The Contractor is pricing a defined scope, not an open brief.
• You have engaged designers who will remain as the independent certifier or who will support the Contract Administrator through construction. The design team maintains continuity.
• Your project requires tight control over design outcomes (material specifications, architectural intent, system design) that you are not willing to delegate to a contractor.
• The project type is relatively conventional: civil earthworks, structural frame, fitout, where design risk is low and construction risk is the primary concern.
• Your funding or procurement rules require a fully priced lump sum at tender. NZS 3910 lends itself to lump sum pricing against a complete design.

NZS 3910 also suits clients who are repeat procurers with established design teams. Councils, government agencies, and large asset owners who run their own panel arrangements typically find the traditional model more efficient because they already have the design capability in house or on retainer.

When is NZS 3916 the right choice?

NZS 3916 is the right contract form when you want the Contractor to take design responsibility and you can define what you need without specifying how to build it.

Choose NZS 3916 when:

• You can write clear Principal's Requirements that describe the outcomes and performance standards you need, but you do not need to specify the solution. The Contractor has the expertise to determine the best approach.
• Programme is a driver. D&C allows design and construction to proceed in parallel, compressing the overall programme. The Contractor does not wait for a complete design before starting on site.
• You want buildability integration from the start. The Contractor designing its own work has an incentive to make it efficient and constructable. Under NZS 3910, design and construction can be siloed.
• Your project is technically complex in ways that benefit from contractor-led innovation: specialist structure, M&E-heavy facilities, modular or prefabricated elements.
• Single-point accountability matters to you. Under D&C, there is one party responsible for the whole outcome. Under traditional delivery, design disputes between the Principal's designer and the Contractor are common and slow to resolve.

NZS 3916 is increasingly the form of choice for Health New Zealand hospital and clinical facility projects, Ministry of Education new-build schools, and government office accommodation. Private developers also use it on commercial and industrial projects where speed to market is a competitive priority.

How does design responsibility differ between the two forms?

Under NZS 3910:2023, the Contractor has no design obligation as a rule. The Contractor builds to the Principal's design documents. If the Contractor identifies a discrepancy between drawings and specifications, it notifies the Engineer and the Engineer resolves it. The Contractor is responsible for workmanship and materials, not for the correctness of the design it is asked to execute.

There are exceptions. Where a Contractor proposes a design alternative, carries out temporary works design, or is asked to design specific elements under Special Conditions, design responsibility can be allocated to the Contractor for those elements. But the default under NZS 3910 is clear: design risk sits with the Principal.

Under NZS 3916:2025, the Contractor's design obligation is the defining feature. Clause 5.1.1 states that the Contractor must design, construct, complete, hand over, and remedy defects in the Contract Works. Design is listed first because it is the primary obligation.

Clause 5.1.3 makes the scope of design clear: the Contractor is responsible for all design work necessary to carry out and complete the works, including design calculations, drawings, specifications, testing, and monitoring of design, unless Specific Conditions say otherwise.

The design standard under NZS 3916:2025 matters. Clause 5.1.5 expressly states:

"The Contractor shall be responsible for carrying out all design work with reasonable skill, care, and diligence."

This is a professional negligence standard, aligned with what professional indemnity (PI) insurance covers. It is not fitness for purpose. The Contractor is not an insurer of outcomes. It must design with the care and skill of a competent professional.

However, clause 5.1.6 adds an absolute obligation alongside the skill and care standard: the Contractor remains responsible for the adequacy, stability, and safety of all its design work and methods of construction. This obligation does not require fault. It is absolute. The interaction between the reasonable skill standard in 5.1.5 and the absolute adequacy obligation in 5.1.6 is a live area of legal interpretation in NZ.

Fitness for purpose can be reintroduced by Special Condition, and frequently is, particularly on government, health, and large infrastructure contracts. Any contractor tendering a D&C project must read the Specific Conditions carefully and confirm that its PI insurance covers the design standard it is accepting.

What are the variations and pricing differences?

Variations work differently under each form because the baseline is different.

Under NZS 3910:2023, a variation is a change to the Contract Works as defined by the drawings and specifications. The Engineer instructs variations, the Contractor prices them, and the Engineer assesses and certifies. The mechanism under clause 9.8 is well established in NZ practice.

Under NZS 3916:2025, a variation is a change to the Principal's Requirements or an instruction by the Contract Administrator that changes the Contractor's scope. This is a meaningfully different threshold. Within the original Principal's Requirements, the Contractor has latitude to develop the design as it sees fit. A change in design approach (using steel instead of concrete, revising the structural system) is not a variation if the outcome still meets the Principal's Requirements. A variation arises when the Principal changes what it needs, not when the Contractor changes how it delivers it.

This distinction is one of the most contested aspects of D&C contract administration. Principals who start requesting design changes mid-construction need to understand that those changes are variations under NZS 3916 and attract cost and time claims. The Contractor's design development within the original brief does not.

On pricing structure, NZS 3916:2025 offers more flexibility than the 2013 edition. Clause 2.1.1 allows three price types: lump sum, cost reimbursement, and target price (or any combination). The target price mechanism at clause 2.4 includes a gain/pain sharing arrangement against a stated target, a collaborative procurement tool borrowed from alliance contracting that is increasingly relevant on complex government projects.

NZS 3910:2023 supports lump sum, schedule of rates, and cost reimbursement. Both forms reference the Construction Contracts Act 2002 for the payment regime. The CCA payment claim and payment schedule framework applies equally to both.

How does NZS 3916:2025 differ from the older edition?

NZS 3916:2025 was published in November 2025. It supersedes NZS 3916:2013. The 2025 edition carries through all changes made in NZS 3910:2023, which means the two current standard forms are now closely aligned in structure and administration model.

The single biggest structural change is the replacement of the Principal's Representative with two distinct roles:

• Contract Administrator (CA): acts for and on behalf of the Principal. Issues instructions, manages design review, and administers day-to-day contract obligations.
• Independent Certifier (IC): acts fairly and independently of both parties. Makes decisions on payment, extensions of time, completion certificates, and disputes referred under clause 6.4.

Under the 2013 form, the Principal's Representative played both roles: acting as the Principal's agent while also exercising quasi-judicial functions. The dual role created tension. The 2025 form resolves it by separating the two functions clearly. The same person may hold both appointments on smaller projects, but must act independently when exercising the IC function.

The 2025 edition also introduced: a formal final account process (cl. 9.11), an early warning obligation (cl. 6.10), an environmental protection clause (cl. 5.20), fault-based indemnity with an optional contractor liability cap (cl. 7.1–7.2), formalised novation provisions with a standard Deed of Novation at Schedule 17, and an optional Design Management Plan (cl. 5.9).

The design standard change from fitness for purpose (market interpretation under 2013) to reasonable skill and care (express default under 2025) is the most commercially significant change for contractors. It aligns the D&C design obligation with what PI insurance covers, which reduces one of the most common coverage gaps in NZ D&C practice.

Common procurement contexts where each form is used

Understanding where each form is typically used helps clarify the procurement logic.

NZS 3910 is typically used for:

• Civil infrastructure: roads, water and wastewater, stormwater, earthworks
• Structural building work where the Principal has engaged architects and engineers who will administer the contract
• Fitout and refurbishment with a defined scope of work
• Local government capital works programmes with established panel arrangements
• PPP and alliance projects where the standard form is used as the base for the project agreement
• Any project where the design team is continuing post-tender to provide technical oversight during construction

NZS 3916 is typically used for:

• Health New Zealand hospital, clinical, and community health facility projects. The sector has moved strongly toward D&C for new builds.
• Ministry of Education new-build schools and early childhood facilities. Standardised design briefs lend themselves to D&C procurement.
• Government office accommodation and fit-for-purpose government buildings. NZTA, NZDF, Corrections, and Crown agencies regularly use NZS 3916.
• Private commercial and industrial development: warehousing, logistics facilities, and commercial offices where speed of delivery is a driver.
• Specialist facilities with significant M&E content where buildability integration from design stage reduces programme and cost risk.
• Projects where novation of the Principal's concept designers to the Contractor makes sense. The Principal commissions concept design, then novates the designer to the winning D&C contractor.

The health and education sectors deserve particular mention. Health New Zealand's infrastructure programme has generated a significant pipeline of D&C procurements over the past three years. The Ministry of Education's rapid response school building programme has used D&C extensively. Both sectors value the single-point accountability and programme efficiency that D&C offers. Both have moved to requiring NZS 3916:2025 on new procurements.

NZS 3910 vs NZS 3916: comparison table

Feature	NZS 3910:2023	NZS 3916:2025
Design responsibility	Principal designs. Contractor builds to the design.	Contractor designs and builds to the Principal's Requirements.
Design risk	Principal carries design risk. Contractor carries workmanship risk.	Contractor carries design risk. Principal carries requirements risk.
Design standard	Not applicable. Workmanship and materials standard only.	Reasonable skill, care, and diligence (cl. 5.1.5). Fitness for purpose requires special condition.
Certifying roles	Contract Administrator (CA) acts for Principal. Independent Certifier (IC) acts independently.	Same CA + IC split. CA issues instructions and manages design review. IC certifies payment, EOT, and completion.
Variations regime	Changes to drawings and specifications. Engineer instructs. Contractor prices. IC assesses.	Changes to Principal's Requirements. CA instructs. Design development within requirements is not a variation.
Payment regime	Monthly payment claims. CCA 2002 applies. Lump sum or schedule of rates.	Monthly payment claims. CCA 2002 applies. Lump sum, cost reimbursement, or target price (cl. 2.1.1).
Defects liability	12-month DLP standard. Workmanship and materials defects. Engineer notifies, Contractor remedies.	12-month DLP standard. Design and workmanship defects. Two producer statements (design at PC, construction at FC).
PI insurance	Not standard. Only required if Contractor has specific design obligations.	Mandatory D&C-specific PI insurance required (cl. 8.6).
Risk allocation	Principal carries design risk, information risk, and site access risk. Contractor carries construction and workmanship risk.	Contractor carries design risk and construction risk. Principal carries requirements risk and Principal's information risk.
Typical project types	Civil infrastructure, structured building, fitout, local government capital works.	Health facilities, education new-builds, government accommodation, commercial and industrial D&C.
Market share (NZ)	Approximately 80% of NZ construction contracts by value.	Approximately 10–15% of NZ construction contracts by value, growing.

What this means for contract administration

The choice of contract form has direct implications for how a project is administered day to day.

Under NZS 3910:2023, the Contract Administrator is managing compliance with a fixed design. The primary obligation tracking tasks are: information provision by the Principal, variations instructed and valued, extensions of time assessed, payment claims certified, and defects notified and remedied during the DLP. The design is a given. Administration focuses on execution.

Under NZS 3916:2025, contract administration has an additional layer: design review. The Contract Administrator reviews Design Documentation as the Contractor produces it. The CA may reject design submissions that do not comply with the Principal's Requirements within 10 working days of submission. After that window, the CA's ability to reject that submission is constrained. Design review timelines are programme-critical. A slow CA on design submissions creates genuine programme risk for the Contractor and potential time bar complications.

The early warning obligation in NZS 3916:2025 (cl. 6.10) applies to all parties. The Contractor must notify the CA as soon as it becomes aware of anything likely to materially affect the contract price or delay practical completion. Failure to give early warning has a financial consequence: variations arising from issues the Contractor should have warned about are valued as if the warning had been given and the impact avoided or reduced.

Provan's intelligence system tracks both forms. Under NZS 3910, it monitors the variation register, time bars, EOT submissions, and payment claim cycles. Under NZS 3916, it adds design submission tracking, CA review deadlines, design rejection notices, and early warning obligations. The obligation profiles are different, but the underlying principle is the same: nothing falls through the cracks on either side of the contract.