In this guide
Use this material to examine your own work. Confirm current requirements, forms and dates with IStructE before applying.
Your portfolio is the main basis for questioning. Reviewers can also ask anything they need to assess each of the ten Core Objectives.
Answer at the level the objective is set at
Use the standard specified for each objective to judge the depth of the example you need.
If an objective is set at Ability, your answer needs to show that you worked unsupervised and could advise someone else. *"I sized the transfer beam"* shows Experience. *"I sized the transfer beam, I set the deflection criterion after talking to the cladding subcontractor, and I reviewed the graduate's version of the adjacent frame"* shows Ability. Same project, different claim.
If an objective is set at Knowledge, do not over-reach into experience you do not have. Reviewers notice, and a candidate who overstates one objective is questioned harder on the rest.
The structure that keeps answers useful
Under pressure, most answers drift into describing the project. A four-part shape keeps them on track:
- The situation: one or two sentences, no more.
- What I did: specific, personal, and in the first person.
- The judgement: what I decided, what I rejected, and why.
- The outcome, and what I would do differently.
Include an honest appraisal of the outcome and what you would change.
When you do not know
Say so, then say what you would do about it. *"I haven't come across that. I'd start by checking the code clause, and I would take it to a colleague who has done it before, because it's outside what I've done unsupervised."*
That answer is not a failure. It is a direct demonstration of the Code of Conduct: undertaking only tasks for which you are competent, and knowing the limits of your competence. Bluffing, by contrast, is the answer that damages you, because reviewers are experienced engineers and the follow-up question will find it.
Practical things that go wrong
- Not knowing your own portfolio. Anything in it is fair game, including work from six years ago.
- Answering as "we". It removes you from your own evidence.
- Talking past the question. If you have not answered in ninety seconds, you have probably drifted.
- Defending an error rather than owning it. Reviewers test judgement, and a candidate who cannot concede a point is showing them something.
- Letting an objective go unmentioned. It is your responsibility to demonstrate all ten.
The same question, two answers
Fictional example: reviewer asks about a temporary works decision
"We had a propping scheme designed by the temporary works engineer, and the contractor installed it. It worked fine and the slab was poured on programme."
"I identified that the transfer slab needed back-propping through two floors — my load take-down showed the floor below couldn't take the wet concrete load at seven days. I set out the requirement and the assumed strength gain, passed it to the temporary works engineer, and checked the returned scheme against my assumptions. I'd challenge the seven-day figure harder now; we took it from the mix design rather than site cube results."
The second answer shows a decision, an assumption, a check of someone else's work, and a self-appraisal: evidence at the Ability level, against health-and-safety and construction objectives at the same time. The first answer describes a project on which the candidate happened to be present.
Questions to ask yourself
- Walk me through a design decision you made that you would now make differently.
It tests self-appraisal, which reviewers weigh heavily and which candidates avoid because it feels like admitting a weakness.
- What did you personally do on this project?
The most common question in the interview, and the one that exposes a portfolio built from team work.
- Who checked this, and what did they change?
It goes straight to the level of supervision, which is what separates Experience from Ability.
- How did sustainability influence this design?
A whole objective, and one where candidates often have the experience but have never articulated it.
- What would you do if you found an error in issued information?
It tests the Code of Conduct and health, safety and risk at once, and the answer is about conduct rather than technique.
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Official sources
Selected publisher pages were rechecked in September 2026. Other source records were last checked in July 2026. Open the latest official document before relying on a requirement.