Writing a design specification
A specification turns a brief into a checklist of exact, testable requirements — the yardstick against which a finished product is judged.
Part of your national curriculum
- Design: Develop specifications to inform the design of innovative, functional, appealing products that respond to needs in a variety of situations
Lesson overview
What you'll learn in this lesson
Develop specifications to inform the design of innovative, functional, appealing products that respond to needs in a variety of situations
Key learning points
- • From brief to specification
- • Balancing user needs
- • Using the specification to test a product
This lesson at a glance
- 20 minutes
- 14 parts to scroll through
- 3 quick checks
- Marked quiz at the end
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 14
Watch first
Writing a design specification
An English teaching video on this topic from Mr T D&T. Watch it, then scroll down for the lesson.
In a nutshell
Develop specifications to inform the design of innovative, functional, appealing products that respond to needs in a variety of situations
Learning cycle
Part 2 of 14
Learning cycle 1 of 2
Part 1 · From brief to specification
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 3 of 14
Learn
From brief to specification
While a brief is a general statement of the problem, a specification lists specific, measurable requirements: for example, 'must weigh under 200g', 'must cost less than £5 to make' or 'must be waterproof for at least 10 minutes'. Vague terms like 'must look nice' are replaced with something you can actually test.
Explore the idea
Part 4 of 14
Learn
Balancing user needs
Specifications should reflect real user needs gathered through research, such as surveys or interviews, not just the designer's own preferences. A specification for a school bag, for instance, might specify strap width for comfort, based on what students said felt uncomfortable in existing bags.
Quick check
Part 5 of 14
Quick check
What makes a good specification point, compared with a vague brief statement?
Reset break
Part 6 of 14
Pause
That's sitting 1 of 2 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Quick check
Part 7 of 14
Quick check
Where should specification requirements ideally come from?
Learning cycle
Part 8 of 14
Learning cycle 2 of 2
Part 2 · Using the specification to test a product
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 9 of 14
Learn
Using the specification to test a product
Once a prototype exists, each specification point becomes a test: does it meet the weight limit? Does it survive the drop test? A good specification means evaluation is not just opinion — it is checking against agreed, specific criteria.
Quick check
Part 10 of 14
Quick check
Which is an example of a testable specification point?
Challenge round
Part 11 of 14
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Challenge round
Part 12 of 14
Game · Fill the gaps
Finish the sentences
Choose the word that belongs in each gap.
____ should reflect real user needs gathered through research, such as surveys or interviews, not just the designer's own preferences.
Mastery quiz
Part 13 of 14
Marked quiz
End of lesson quiz: Writing a design specification
4 questions, marked with the reasoning shown. No timer.
1. Which is the most useful design specification point?
2. What makes a good specification point, compared with a vague brief statement?
3. Where should specification requirements ideally come from?
4. Which is an example of a testable specification point?
Lesson round-up
Part 14 of 14
Lesson round-up
Ready when you are
Quiz score
Not sat
Games
Not played
Points this lesson
0
Best run
0 in a row
Luna: 0 out of 3 on the practice checks. Only if you feel up to it — one more?
Ask LunaDo the work
Your written work for this lesson
This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.
Why the first prototype broke
A team designed a phone stand from 3 mm plywood. The brief said it must hold a 200 g phone at 60° and survive being knocked. The first prototype looked right but snapped at the joint after two knocks.
The team tested again and found the grain of the plywood ran across the narrowest part of the joint, so the wood split along it. They widened the joint from 8 mm to 20 mm, turned the piece so the grain ran along the load, and added a small fillet at the corner to spread the force.
The second prototype survived twenty knocks. It used 15% more material and took four minutes longer to cut — a trade-off the team recorded in their evaluation.
Written for Good Learning Co.
Reading questions
- Name the fault in the first prototype and explain why it happened.
- List the three changes the team made and what each one does.
- Write an evaluation of the second prototype against the brief, including the trade-off.
Design sheet
DiagramSketch two ideas with measurements and notes, then photograph the sheet.
2 labelled sketches
Evaluation
WritingWrite how well your idea meets the brief and what you would change next time.
6–8 sentences
Saved as you type.
Part 1 of 14 · Watch & discover
How this is going
- Not looked at yet
Develop specifications to inform the design of innovative, functional, appealing products that respond to needs in a variety of situations