A practical explanation of the role, what can be delegated, what stays with the Engineer and why the difference matters on site.
The short answer. The Engineer’s Representative is not the Engineer. On an NZS 3910 contract, the Engineer holds the contractual powers, certifying payments, granting extensions of time, valuing variations and giving instructions that carry cost or time. The ER acts for the Engineer on site, day to day, but only for the parts of that role the Engineer has actually delegated in writing. Mix that up and you get arguments later about who said what and whether it counts.
Most Engineers are not on site every day. On a project of any size the Engineer needs someone watching the work as it happens, checking it against the drawings and specification, picking up notices and issues early and keeping the programme under review. That is what the ER is there for. It lets the Engineer stay across the whole contract while someone with the right experience is on site full time.
In my experience this normally covers:
These decisions carry contractual and financial weight. They are not normally delegated:
An ER can prepare the analysis and put a recommendation to the Engineer on any of these. What an ER cannot do is make the call themselves, unless the delegation specifically says so.
I have seen this cause real problems both ways. A contractor who treats a comment from the ER as a final answer on a variation, then finds the Engineer takes a different position, has lost time acting on something that was never actually decided. An ER who oversteps and gives a firm answer outside their delegation creates risk for the principal, because the other side may reasonably rely on what they were told.
The fix is simple and should happen on day one of the contract. The Engineer sets out in writing exactly what has been delegated to the ER. Both parties get a copy. If anyone is not sure whether something is within the ER’s authority, they ask, rather than assume.
On every contract where I am acting as ER, I ask for the delegation in writing before I start making calls on site. I make sure the contractor knows what I can decide and what has to go back to the Engineer. It takes an hour at the start of a contract and it saves a lot of argument later about whether something was actually approved.
I take on Engineer’s Representative roles on NZS 3910 contracts across the Bay of Plenty and Waikato, direct or as a subconsultant to the lead consultant. Get in touch.
Common questions
No. The Engineer is appointed under the contract and holds the contractual powers. The ER is appointed by the Engineer to act for them on defined matters, set out in a written delegation.
Only if the delegation specifically gives them that authority. Most delegations keep variation valuation and approval with the Engineer, with the ER preparing the assessment.
It does not bind the Engineer or the principal in the way a properly authorised instruction would. This is exactly the kind of situation that ends up in dispute, because the contractor may have relied on it in good faith.
It should be. A verbal or assumed delegation is where most disagreements about authority start. Ask for it in writing if you have not seen it.
Ask the ER directly. If there is any doubt, ask the Engineer to confirm the scope of delegation. It is a reasonable question and any properly run contract should have a clear answer.
Have a specific question
This page is general guidance. For a question about your own contract, use the free tool or get in touch directly.