In this guide
Use this material to examine your own work. Confirm current requirements, forms and dates with IStructE before applying.
The supplementary paper has three parts and eighty marks, with half the writing time of the other two papers. Check the timetable carefully when preparing.
Two-thirds of the paper is part a
Part a carries 54 of the 80 marks. On a 3½-hour paper that is well over two hours of the day, and it is where the examination is won or lost.
What it asks for is the Chartered paper's opening section with one addition: feasibility concept calculations to justify the schemes. These are not full designs. Elements may be sized using engineering judgement or rule of thumb (span-to-depth ratios and the like) and reference to design guides or manufacturers' literature should be noted where used. Full design calculations for two principal elements belong in part c, not here.
The definition of "distinct" is the same as on the Chartered paper: stability, framing, foundations, materials, load path, construction method, with changing only one of them being insufficient. For the bridge question, a different form of structure with different spans or load paths.
What is not in this paper
There is no professional communication section and no construction method statement. If you are preparing from Chartered Membership material (which is reasonable, since parts a and b mirror it) do not spend rehearsal time on sections you will not be asked to write.
Part c is small, and easy to over-run
Six marks. Two elements. Bending and shear with a span-to-depth deflection check will be adequate for most members, and the carbon calculation is mass times embodied carbon factor.
Six marks out of eighty is about sixteen minutes of a proportionally-spent day. Candidates who treat part c as though it were the Chartered paper's section 2c lose part a marks they cannot recover.
Plan the day for 3½ hours
This is worth stating plainly because the consequence is severe and the cause is trivial. The other two papers give you seven hours of writing with a lunch break in the middle. This one gives you three and a half, continuously, and ends when the others are breaking for lunch.
Every mock you sit should be to the shorter timetable.
How to spend 210 minutes
| Situation | Marks | Roughly, at 2.6 minutes per mark |
|---|---|---|
| Part a: two schemes, feasibility calcs, recommendation | 54 | About 2¼ hours |
| Part b: critical details | 20 | About 50 minutes |
| Part c: two elements and their carbon | 6 | About 16 minutes |
The preparation timetable calculated from the published marks and the 210-minute paper. Reading, thinking and checking time have to come out of these figures, so the real writing allowance is shorter still.
Preparing for this paper specifically
Look for
- Rehearse to 3½ hours with no break, every time
- Practise selecting critical details from a scheme you invented an hour earlier
- Keep part a's calculations at feasibility level: judgement and rules of thumb
- Carry embodied carbon factors and densities in your folder for part c
- Make the two schemes distinct on three or four counts, as on the Chartered paper
Watch for
- Prepare on a seven-hour timetable
- Prepare a professional communication or a method statement: this paper has neither
- Treat part c like the Chartered paper's section 2c
- Draw generic typical details for part b
- Leave the recommendation unstated
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.