Engineering consultancy disputes overwhelmingly arise from the same root cause: the parties had different understandings of what was being provided. The fee was agreed, the deliverable was described in general terms, and the detail was left to be worked out — which works until something goes wrong.
Scope is the document that matters
A usable scope statement answers questions that feel obvious until they are disputed:
- What deliverables, in what form, at what stage — concept, developed design, detailed design, construction documentation.
- What is excluded. The exclusions list is more valuable than the inclusions list, because it captures what the client assumed was included.
- What assumptions the design rests on, including information supplied by others.
- Whether construction monitoring is included, at what frequency, and whether a producer statement will be issued at the end. This is the most commonly disputed item in New Zealand engineering engagements.
- How many revisions are included before variation applies.
- Who else is providing input and what you are relying on from them.
The producer statement problem
The recurring pattern: an engineer is engaged for design, the project proceeds, and at completion the client asks for a PS4 covering construction the engineer never monitored.
A PS4 is a professional opinion that construction monitoring was carried out and the work accords with the design. Issuing one without having done the monitoring is a disciplinary matter and creates liability far exceeding the fee.
The answer is at engagement, not at completion. State explicitly whether construction monitoring is in scope, what level of monitoring the fee covers, and that a PS4 will only be issued if that monitoring occurs. Clients who decline to pay for monitoring should understand at the outset that no PS4 follows.
Fee structures
Lump sum gives the client certainty and puts scope risk on the engineer. It works where scope is genuinely well defined and is dangerous where it is not.
Time and materials puts scope risk on the client. It suits investigative and early-stage work where the extent of the problem is unknown.
Percentage of construction cost is traditional in some sectors and has an obvious misalignment — the fee rises with construction cost, which the engineer influences.
Capped time and materials is often the practical compromise, with a mechanism for raising the cap if scope changes.
Whichever is used, define what triggers a variation to fee and how it is agreed. A variation mechanism that requires written agreement before additional work proceeds protects both parties.
Liability, caps and insurance
This is where the real money sits, and where fee negotiation attention is misdirected.
A liability cap limits the engineer’s exposure, commonly to a multiple of fees or a stated sum. Without one, exposure on a small-fee job can be enormous, because the loss relates to the project rather than the fee.
Professional indemnity insurance should be current, adequate for the exposure, and — critically — maintained after the engagement ends. PI operates on a claims-made basis, meaning the policy in force when the claim is made responds, not the one in force when the work was done. An engineer who retires or lets cover lapse has no protection for historic work, which is why run-off cover matters.
Limitation. The Building Act contains a long-stop limitation period for civil proceedings relating to building work. It is long, and it means work done today can be examined many years later — usually by people reading the file rather than talking to you.
Reliance and third parties
Design documents frequently end up in the hands of parties who were not the client — purchasers, financiers, contractors, subsequent owners.
Address reliance explicitly. Who may rely on the documents, for what purpose, and whether a reliance letter or duty of care deed will be provided and on what terms. Uncontrolled reliance is uncontrolled exposure.
Practical engagement checklist
- Written engagement before work starts, every time, including for small jobs and repeat clients — those are where the disputes cluster.
- Scope with an explicit exclusions list.
- Producer statements addressed expressly, including monitoring level.
- Fee basis and variation mechanism defined.
- Liability cap agreed, with PI cover confirmed as adequate.
- Reliance and document use addressed.
- Dispute resolution process specified.
Engineering New Zealand publishes model terms of engagement and practice guidance for members, and the standard conditions of contract used in New Zealand consultancy come with commentary. For any engagement where the potential loss materially exceeds the fee, the terms deserve more attention than the rate.
General information only, not legal advice.
