Key Idea: Three problems: waste, pollution, energy consumption. All three are affected more by how long a product lasts than by what it is made of. Ask where the impact is — in making it, or in using it — because the right strategy for one is nearly useless for the other. Datchefski's five: cyclic, solar, safe, efficient, social. Efficient is measured per year of service. The triple bottom line is people, profit and planet, measured together — and the account that is quietly paying is where the design opportunity is.
Paper 1 — multiple choice
- Pick the strategy with the largest effect for a product
- Say where the impact of a named product lies
- Match a feature to one of Datchefski's principles
- Identify which account of the TBL an effect falls on
Paper 2 — analysing a product
- Explain how a strategy differs between two products
- Analyse a product against the five principles
- Explain a TBL conflict and how it is resolved
- Evaluate a decision on all three accounts
Carried into the design project
- Criterion E — the impact of your own solution
- Environmental criteria belong in the specification, testable
- Every claim needs a measure, a cost and an alternative
This is the first question in every sustainability answer, and getting it wrong makes everything after it irrelevant.
| Impact mostly in… | Products | The strategies that work |
|---|---|---|
| USE | Kettles, heaters, fridges, cars, anything powered | Insulate, control, switch off, reduce the amount consumed per use |
| MAKING | Chairs, tools, packaging, furniture, buildings | Fewer processes, less mass, a longer life, less transport |
| Both, always | Everything | Make it LAST — doubling the life halves material, energy and waste at once |
Double how long a product stays in use and you halve its material, its energy and its waste — all three at once. No material substitution comes close, which is why a sustainability answer that only swaps a material is a weak one.
Strategies ordered by how much difference they make, and the question that decides which are worth anything.
🔒 Interactive diagram
Explore the labelled diagram, charts and maps for this topic in study mode.
| Principle | The test question | Where products usually fail |
|---|---|---|
| Cyclic | Where does every part go when it is finished with? | A laminate or a glued joint somewhere |
| Solar | What energy to make it, and what does it use? | A grid mix nobody asked the supplier about |
| Safe | What is released, to whom, at each stage? | A fabric treatment or a coating |
| Efficient | How much mass and how many processes, per year of service? | A light product with a short life |
| Social | Who made every part, and under what conditions? | Below tier one of the supply chain |
Important: Reaching for a material substitution before asking where the impact is. Scoring a product five out of five on the principles — look again at cyclic and social. Treating profit as the enemy. A design that loses money is never made, so it helps nobody.
Most products sit in a pairwise overlap. Naming which pair, and who pays, is a strong answer.
🔒 Interactive diagram
Explore the labelled diagram, charts and maps for this topic in study mode.
A company makes a patio heater and a wooden picnic bench. Explain how the sustainability strategy should differ between them.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
A coffee chain replaces disposable cups with a deposit-return reusable cup. Evaluate this against the triple bottom line.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Why is product life the biggest lever?
Why ask where the impact is first?
Why is efficiency measured per year of service?
Where does the social principle usually fail?
What are the three accounts of the triple bottom line?
What is a transfer?
Exam tips
- Say where the impact is — making or using — before choosing a strategy.
- Product life is the biggest lever. Name it first.
- Give a measure: per year of service, per use, per litre delivered.
- Efficient means per year of service, not lighter.
- Work the three accounts separately, and check for a transfer afterwards.
- Treat profit as an account to satisfy, not a villain.