In this guide
Use this material to examine your own work. Confirm current requirements, forms and dates with IStructE before applying.
Apply the embodied-carbon formula to the elements you have designed. Since January 2024, sustainability has been a feature of every question on every paper.
Carbon requirements in the paper
Section 2c on both Chartered and Incorporated papers requires the form, size and approximate A1–A3 carbon footprints of the principal structural elements. Part c of the supplementary paper requires this for two principal elements.
At scheme selection in 1a, full carbon comparisons are not required. Explain how structural efficiency minimises material and how you use any reuse opportunity offered by the brief.
Estimating the footprint
- Calculate volume from the section and length established in your sizing.
- Multiply by density to obtain mass.
- Multiply by the embodied carbon factor, including grade or recycled-content assumptions where relevant.
- State the factor's source and assumptions.
Round to a precision appropriate to an approximate footprint and explain the rounding. Four significant figures may imply more certainty than the inputs support.
Preparing reference information
Prepare a short sheet of likely materials with densities and industry-average factors: concrete grades, reinforcement, structural steel, timber and masonry. Use the Institution's free course and *How to Calculate Embodied Carbon* document. Recommended industry-average values provide a consistent basis where online checking is unavailable.
The calculation, element by element
- 01
Take the volume from your own sizing
You already have the section and the length from the design calculation, so no new work is needed.
- 02
Convert to mass
Volume times density. Carry the densities you use most into the exam in your folder, so this is arithmetic rather than a search.
- 03
Multiply by the embodied carbon factor
For the material and, where it matters, the grade or the recycled-content assumption you are making.
- 04
State the source and the assumption
Which factor you used and where it came from. Industry-average values are recommended, and saying so is part of the answer.
- 05
Round, and say that you have
It is an approximate A1–A3 footprint. Quoting it to four significant figures invites a question about what you think you know.
In your folder before the exam
Ticked locally in this browser. The Institution's own guidance and its free embodied carbon course are the intended preparation.
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.