IB MYP Design – Sustainable and ethical design Study Guide

This study guide teaches sustainable and ethical design for IB MYP Design. It is aligned to the International Baccalaureate Organization, Middle Years Programme Subject Brief – Design, from 2014, and suits MYP years 4 and 5. There is no SL/HL split in MYP, and the same ideas apply whichever session you submit your ePortfolio in.

MYP has no prescribed content list – schools design their own units. This page covers two related concepts the IB’s brief names for design, sustainability and ergonomics, plus the ethics of handling users’ data, and shows how each one feeds criterion A (Inquiring and analysing) and criterion D (Evaluating). Your teacher will share the task-specific clarifications for each criterion.

Use it with the revision notes and the practice questions. For the wider course, see the course hub, the printable checklist, the design cycle and criteria in practice.

What this unit covers

Idea	What you must be able to do	Where it earns credit
Life-cycle thinking	Name the five life-cycle stages, compare two designs fairly, spot the stage with the biggest impact	Criterion A research; criterion D impact
Materials choice	Weigh function, sustainability and cost; justify a choice with evidence	Criterion A research; the specification in B
Ergonomics	Use anthropometric data and percentiles to size a product	Criterion A research; criterion D testing
Inclusive design	Design for the widest range of users, not the “average” user	Criterion A analysis; criterion D impact
Data ethics	Collect only the data you need, get consent, keep it secure	Criterion A analysis for digital design; criterion D impact

Why the brief puts this in design

The brief says MYP design should raise your awareness of your responsibilities when you make design decisions. Two of its aims point the same way: appreciating the impact of design on life, global society and environments, and acting with integrity and taking responsibility for your own actions. The brief also lists the global context Globalization and sustainability, and Fairness and development, which suits inclusive and ethical design. None of this is a separate criterion: it is evidence for A and judgement in D.

Life-cycle thinking

A product affects people and the environment at every stage of its life, not only when it is made. Five stages are usually used:

1. Raw materials – extracting and refining the materials (mining ore, felling timber, drilling oil for plastics).
2. Manufacture – shaping, joining and finishing parts; packaging.
3. Distribution – transport to shops and to the user.
4. Use – energy, water or consumables used while it works; cleaning, repairs, software updates.
5. End of life – reuse, repair, recycling, composting, incineration or landfill.

Looking at all five is often called cradle to grave. Cradle to cradle thinking goes further: design so that materials at end of life become the raw materials for something new.

The 6 Rs

A quick checklist for improving a design:

• Rethink – is there a better way to meet the need?
• Refuse – leave out parts, packaging or features that are not needed.
• Reduce – use less material and less energy in use.
• Reuse – design for a second life, as is or for another purpose.
• Repair – make parts easy to replace with ordinary tools.
• Recycle – use single materials where possible, label them, and make them easy to separate.

Designing for disassembly (screws and clips rather than glue; no mixed-material laminates) supports the last three.

Compare per functional unit

A fair comparison uses the same functional unit – the job done, such as “one year of packed lunches”. A product that costs more energy to make can still win if it lasts much longer.

Worked example 1 (fictional data). Two lunchbox designs. Energy in megajoules (MJ):

Stage	P: polypropylene, lasts 5 years	S: stainless steel, lasts 12 years
Raw materials	18	45
Manufacture	6	10
Distribution	2	3
Use (washing, 3 MJ per year)	3 × 5 = 15	3 × 12 = 36
End of life	1	1
Total	42	95

Step 1: Totals. S uses more energy in total (95 MJ against 42 MJ).

Step 2: Per functional unit. P: 42 ÷ 5 = 8.4 MJ per year. S: 95 ÷ 12 ≈ 7.92 MJ per year.

Step 3: Conclusion. Per year of use, S has the smaller energy impact, but only if it really lasts 12 years. If the lid breaks after four years and cannot be replaced, the advantage disappears. That is why repairability belongs in the specification.

Step 4: Biggest stage. For both designs raw materials is the largest single stage (18 of 42 for P; 45 of 95 for S), so material choice matters most here.

Energy is only one measure; water, emissions and waste are others. Say which you used and where the data came from.

Materials choice

Choose materials against three groups of criteria:

• Function – strength, stiffness, hardness, toughness, weight, resistance to water, heat and sunlight, food safety.
• Sustainability – renewable or finite source, energy used to produce it (embodied energy), recycled content, how easily it is recycled or composted, toxic by-products, distance travelled.
• Practicality – cost, availability in your school workshop, the processes you can use, finish and appearance.

Some trade-offs to know:

• Timber is renewable, but only if forests are managed. Certification schemes such as the Forest Stewardship Council (FSC) label wood from managed sources.
• Metals such as aluminium and steel can be recycled many times without losing their properties, and recycling them uses far less energy than making them from ore.
• Thermoplastics (PET, HDPE, PP) can be remelted and recycled, but mixed or dirty plastics often are not. Thermosets cannot be remelted.
• Bioplastics such as PLA are made from plant sources, but “biodegradable” does not mean it breaks down in a garden heap – PLA generally needs industrial composting conditions.
• Composites (for example glass-fibre reinforced plastic) are strong and light but hard to separate for recycling.

A weighted decision matrix

A matrix makes your reasoning visible, which is exactly what criterion A research and the B specification need.

Worked example 2 (fictional scores). An outdoor planter for a school garden. Each material is scored 1–5 (5 = best) and multiplied by the criterion’s weight.

Criterion (weight)	Recycled HDPE	FSC timber	Galvanised steel
Durability outdoors (×3)	4 → 12	3 → 9	5 → 15
Low embodied energy (×2)	4 → 8	5 → 10	2 → 4
End-of-life options (×2)	3 → 6	4 → 8	4 → 8
Cost (×1)	3 → 3	4 → 4	2 → 2
Total (out of 40)	29	31	29

Timber wins narrowly. Notice what the matrix shows: if durability were weighted ×5, steel would score 39 and win (timber and HDPE 37 each). So you must justify the weights from your research into the client’s need. The numbers do not decide for you.

Ergonomics

Ergonomics is designing a product to fit the people who use it. Three kinds of data are used:

• Anthropometric – body sizes: heights, reaches, hand widths, grip diameters.
• Physiological – strength, fatigue, comfort, temperature, noise and vibration.
• Psychological – how people perceive and react: colour, feedback, clarity of controls, stress.

Percentiles

Anthropometric data are given as percentiles. The 5th percentile value is the size that 5% of the group are smaller than; the 95th percentile value is the size 95% are smaller than. Designing from the 5th to the 95th percentile fits 90% of that group.

Three strategies:

• Design for the extreme. Clearances (door heights, handle openings) use the 95th percentile so large users fit. Reaches (shelf heights, control positions) use the 5th percentile so small users can reach.
• Design for adjustability. Chairs, straps and stands adjust across the range.
• Design for the average. Only when adjustment is impossible and fit matters little.

Worked example 3 (fictional data). A workshop stool for 13–16 year olds. Popliteal height (floor to the back of the knee, seated): 5th percentile 380 mm, 50th 425 mm, 95th 470 mm. Allow 25 mm for shoes.

Step 1: Lowest seat height = 380 + 25 = 405 mm.

Step 2: Highest seat height = 470 + 25 = 495 mm.

Step 3: Adjustment range needed = 495 − 405 = 90 mm.

Step 4: A fixed 450 mm stool (50th percentile plus shoes) would leave small users’ feet dangling and large users’ knees raised. The data justify adjustability.

Always check that the data set matches your target audience – adult data will not suit a primary-school product.

Inclusive design

Inclusive (or universal) design aims for products that the widest possible range of people can use without special adaptation. The seven principles of universal design are a useful checklist: equitable use; flexibility in use; simple and intuitive use; perceptible information; tolerance for error; low physical effort; size and space for approach and use.

In practice:

• Offer more than one way to get information – a sound and a light, text and an icon.
• Use large, high-contrast controls, and never rely on colour alone (red and green look similar to many colour-blind users).
• Keep forces low: lever handles instead of round knobs, large grips.
• For digital design, follow accessibility guidance such as the W3C’s Web Content Accessibility Guidelines (WCAG): text alternatives for images, keyboard navigation, readable contrast, captions.

Inclusive design often helps everyone: a ramp serves wheelchair users, parents with buggies and delivery workers.

Ethics of data in digital design

If your solution is an app, website or system, the data it collects is a design decision. Five principles:

1. Data minimisation – collect only what the solution needs. A homework planner needs a task name and due date; it does not need a home address.
2. Informed consent – tell users, in plain language, what you collect and why, and ask before collecting it. Consent is a clear choice, not a pre-ticked box.
3. Security – protect stored data with passwords, access control and encryption where possible. Do not store passwords as plain text.
4. Transparency and control – let users see, correct and delete their data.
5. No manipulation – avoid “dark patterns”: hidden cancel buttons, confusing wording, nagging pop-ups that push users into choices they did not intend.

Many countries have data-protection laws, such as the EU’s General Data Protection Regulation (GDPR). In criterion A, find out whether your client’s school or organisation has rules about student data. Algorithmic bias also matters: a system trained or tested on one group may work worse for others, so test with a varied group.

How this feeds criterion A

The brief says in criterion A you analyse the need for a solution and inquire into the nature of the problem. Sustainable and ethical design gives you research questions worth asking:

• Which life-cycle stage of existing products has the biggest impact, and why?
• What materials do existing products use, and what happens to them at end of life?
• What anthropometric data fit my target audience? Which percentiles matter for each dimension?
• Who might be excluded by existing products?
• What data would a digital solution need, and what should it not collect?

Record the source of every figure and judge its reliability.

How this feeds criterion D

The brief says in criterion D you explain how your solution will impact on the client or target audience. Strong impact statements are specific and balanced:

• Weak: “My product is eco-friendly.”
• Stronger: “The stand uses 70% recycled aluminium and is held together with four screws, so the user can replace a broken arm instead of buying a new stand. It still needs energy to recycle at end of life.”

Test ergonomic claims with real users across the size range, not only yourself. For digital solutions, test with users who have different needs and report what the solution does with their data.

Common errors

• Comparing total energy for products with different lifespans, instead of per functional unit.
• Calling a material “sustainable” without saying which life-cycle stage or measure you mean.
• Using adult anthropometric data for a teenage or child audience.
• Using the 50th percentile for a clearance, so larger users do not fit.
• Treating a decision matrix as proof without justifying the weights.
• Listing universal design principles without applying one to your product.
• Collecting personal data “just in case” in a digital solution.

Official syllabus

International Baccalaureate Organization, Middle Years Programme Subject Brief – Design, from 2014 (published by the International Baccalaureate Organization, © 2015). Ergonomics and sustainability appear in the brief as examples of related concepts; subject content on this page is standard design practice written by Marlbridge.