EC-16.4 Lifecycle, Environmental Impact and Accessibility

What this is and why it exists

Both halves of this topic share one structural insight, and it is worth stating before either.

The decisions that matter are made early and cheaply, and become expensive or impossible later.

A material chosen at the design stage decides most of a product's environmental cost. An interface designed to be usable from the start is cheaper than any later adaptation and works better. Neither can be added at the end at any price worth paying.

The vocabulary

• Lifecycle assessment — accounting for impact across materials, manufacture, use and disposal.
• Embodied energy — the energy used to produce something, before it is ever switched on.
• Design for repair — choices that make a product serviceable.
• Electronic waste — discarded electronics, containing both hazardous and valuable materials.
• Accessibility — designing so that people with differing abilities can use the result.
• Assistive technology — tools such as screen readers that people use to operate a system.

The mental model

Impact is counted across the whole life: materials, manufacture, transport, use, and what happens at the end.

A device that uses less power in service can still cost more overall, if its manufacture or its disposal is worse. That is not a hypothetical; it is the usual finding for products whose use phase is short or whose materials are difficult.

Counting only the use phase is the standard error. It is attractive because the use phase is the only part that appears on a specification sheet.

Three levers dominate the total, and efficiency in use is not usually one of them.

Material choice, because embodied energy varies enormously between materials and because some materials make recovery impossible. Expected lifetime, because a product used for eight years amortises its manufacture over four times as long as one used for two. And repairability, which is what decides whether the lifetime is reached.

Designing for repair is a set of concrete choices. Fasteners rather than adhesive. Spare parts that remain available. Materials that separate rather than being bonded together. Service information that is published rather than withheld.

Each is a decision made at design time and none can be added afterwards. A product glued shut is glued shut for the rest of its existence.

Electronic waste deserves its own mention because the failure mode is specific. Electronics contain hazardous substances and valuable ones in the same object.

Informal recycling recovers a little of the second while exposing people to the first, usually people far from where the product was designed or used. Design decisions affect how recoverable a product is. That is an ethical consequence of a technical choice, which is the theme this module returns to.

Now accessibility, which follows the same structure exactly.

Consider an interface that works with a screen reader, offers keys as well as a touchscreen, and does not rely on colour alone. It works for far more people than one that does not. All three are decisions, and all three cost almost nothing when made at the start.

Retrofitting any of them is harder and produces a worse result. A separate accessible version is worse still: it is maintained less, tested less, and is usually behind.

Finally, testing with people whose abilities differ from yours.

A designer's own experience is the least representative sample available, because a designer knows where everything is and how it was meant to work. Test with someone who uses a screen reader, or who has limited fine motor control, or who is working one-handed. It reveals problems that no checklist would have found.

That is the same argument the design module made about validation, applied to a group of users who are usually left out of it.

What you should now be able to explain or do

• Account for impact across a whole lifecycle rather than at the point of use.
• Name the three levers that dominate environmental impact and rank them against efficiency.
• List the concrete choices that make a product repairable.
• Explain why informal recycling of electronics is harmful and how design affects it.
• Name three accessibility decisions that cost nothing when made early.
• Argue for testing with people whose abilities differ from the designer's.

Check yourself