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A single requirement can collapse the design space

2026-08-04 · 10:09 UTC ·@Object_Zero_ ·2 min read

Brief

Designer @ObjectZero (posted 2026-08-04) argues that design is driven by requirements: adding constraints (e.g., “carry lots of people”) collapses choices and produces distinct solutions (passenger vs fighter jets). Material choices, winglets, control-surface sizes and fastener patterns let you reverse-engineer intent. Time and capital create compromises, and AI could change that dynamic over the next 15 years.

Why it matters

A single requirement can collapse the design space: for two jets, the requirement to “carry lots of people” forces a central fuselage cabin with fuel tanks and propulsion mounted outboard on the wings (passenger jet), while a fighter jet centers the engine and wraps structure around the powerplant.

Key details

  • Cockpit placement is constrained by landing visibility—pilot must see the runway—so cockpit location stays constant; observable choices like winglets vs large flat panels, aluminium vs composites, and control-surface sizing betray original design requirements.
  • Bad design often appears as wrong fastener choice or pattern and load-path/separation errors; most products are compromised by limited time and capital, and AI may reshape this resource-driven imperfection over the next 15 years (author @Object_Zero_, posted 2026-08-04).
Source evidence

Design Requirements

If you design a lot of things, especially mechanical things, then the whole world look very different to you.

You gain a designers eye, and it’s a skill that you never lose, and is with you to the grave.

It’s a bit of a double edged sword because the vast majority of the world is badly designed and you will be acutely aware of this at all times, so bit of a curse tbh.

However, some things are incredibly well designed, and it’s a joy to appreciate them from a design perspective.

For example, the two images below are two jets one passenger jet, one fighter jet.

Both would be valid solutions to “design a jet”.

But as soon as you apply 1 requirement the design space collapse, and it collapses further with each additional requirement.

The moment you say “design a jet to carry lots of people” you immediately have to put the cabin in the center of the fuselage, the fuel tanks and the propulsion move outboard to live on the wings.

The fighter jet is the opposite, the engine takes precedence, everything else is wrapped tightly around the power plant, because it’s all about getting into position and controlling position.

The cockpit always has to have the same location so the pilot can see the runway and land the thing in all sorts of scenarios.

When you take this into the detail, you can start to reverse engineer the requirements by looking at a design. You can see what the intention is just by observing the thing.

Winglets v’s big flat panels, aluminium v’s composites, relative size of control surfaces, these all seem obvious (they are), but they all betray the design requirements.

Sometimes you can see concessions, such as the engine position on the left, and other things on the right.

Bad design often looks like wrong fastener choice, or wrong fastener pattern, once you understand mechanical load paths and separation contacts vastly majority of product have lots of issues.

But design itself is resource constrained, often people don’t have time or capital to get things optimal, so they release designs because the budget is exhausted rather than the problem set is resolved.

The advent of AI might change this dynamic, and will be very cool to observe how things develop over the next 15 years.

Maybe everything will be perfect? 🤣