Worked example First Principles Thinking  ·  October 2026  ·  8 min read

What would it take to get takeaway coffee cups out of Sydney's bins for good?

Greater Sydney buys a lot of coffee to go, and almost all of it comes in a cup designed to be used once. This worked example takes that everyday habit apart, piece by piece, and arrives at a direction that does not ask anyone to give up their coffee run.

A thought experiment. TKD advisory worked through a public problem to show how the method works in practice. It was not commissioned by, and is not advice to, any council or government.

Worked through by

Tom Kortenbach-Dijkstra

Founder, TKD advisory

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~100%

of takeaway cups today end up in landfill

≤10%

the objective for June 2035: a 90% cut, by avoiding, reusing or recycling

How to read this

First Principles Thinking does not start by brainstorming solutions. It takes the problem apart, tests every assumption along the way, and keeps only what is actually known to be true. The solution is then built from those parts. At every step, a common assumption is put to the test, marked Assumption tested. Every claim also carries a label for how solid it is:

Verified: backed by a named source Reasoned: a well-argued conclusion, not yet tested locally Open assumption: flagged for future testing
01

The Problem

Getting specific about who, where and how big.

5.64M

People living in Greater Sydney, the scope chosen for this example 1

100k–1M

Estimated takeaway cups used per day across the region, scaled down from the national figure 2

Assumption tested

AssumedThis is a problem for the City of Sydney council area.

Holds?No

InsteadPeople travel from across the metro region to buy their coffee in the city. The scope has to be Greater Sydney, even though waste policy is set council by council. That gap matters later.

Open assumption

No local number exists yet

There is no Sydney-specific count of how many cups are thrown away each day. The estimate above takes the national figure of more than a billion cups a year and scales it to the region's share of the population. That is useful for sizing the problem, but not precise enough to measure progress against. A local count is one of the first things worth commissioning.

02

The Objective

One measurable goal, kept clean of any solution.

By June 2035, no more than 10% of Greater Sydney's takeaway coffee cups end up in landfill.

That is a 90% cut, and the route does not matter. Fewer cups used in the first place, more cups reused, or more cups properly recycled all count. The objective deliberately does not lock in one route.

Assumption tested

AssumedThe goal is to recycle more cups.

Holds?No

InsteadWhat matters is fewer cups in landfill. Using fewer cups, reusing them and recycling them all count, so the objective names the result, not the route.

Self-set ambition

Not borrowed from existing policy

The City of Sydney's waste strategy sets 90% diversion targets for 2030, but none for coffee cups specifically. 3 This objective is inspired by that ambition, not copied from it. A public body would need to adopt it formally.

Verified

Why it matters

The NSW EPA expects Greater Sydney's landfill space to run out by 2030 unless urgent action is taken. 4 A deeply ordinary daily habit adds to that pressure, which makes it a sensible place to show what is possible.

03

The Obstacles

What actually stands in the way, and what is deliberately left alone.

VerifiedA fragmented marketAround 95% of Australia's cafés are independently owned. 5 There is no chain to coordinate through, so any fix has to work without one.
ReasonedA material stuck by defaultDisposable cups have a plastic lining that blocks normal recycling. Better materials exist; they are just not the cheaper choice yet.
ReasonedPeople forgetEven people who own a reusable cup do not always have it with them. Any fix has to work in the moment someone forgets.
VerifiedRegulation is coming slowlyUnder NSW rules, takeaway businesses must accept reusable cups by 2028, and single-use cups must be recyclable from mid 2028. 6 Neither sets a target for fewer cups in landfill.

Assumption tested

AssumedDisposable cups simply cannot be recycled.

Holds?No

InsteadBetter materials already exist. The obstacle is price, so it belongs in the solution, not in the principles.

AssumedLess takeaway coffee is part of the answer.

Holds?Set aside

InsteadNot the target. Whatever is built has to stay as convenient as grabbing a cup and going, or people will not use it.

04

The First Principles

What is left once the assumptions are stripped away. The solution has to be built on these.

Four first principles, each tested against a common assumption

1
Reasoned

Assumption tested“Cafés can solve this together, voluntarily.” No

No single business can coordinate this. Only government can.

With no dominant chain to lead the way, only regulation can move the whole market at once. Any voluntary approach will only ever reach the willing few.

2
Reasoned

Assumption tested“The NSW rules will take care of it.” No

Waiting for the State is not a plan.

NSW rules arrive in 2028 and still will not close the gap. Reaching 90% by 2035 means Sydney has to move on its own timeline, not the State's.

3
Open assumption

Assumption tested“People will not accept paying more.” Partly

When someone forgets their cup, the fallback has to visibly serve the goal, not the till.

People are not against paying a little more or doing a little more, as long as they can see it going towards the goal instead of quietly becoming extra profit. Reasoned from evidence gathered elsewhere, not yet tested in Sydney.

4
Verified

Assumption tested“A discount for bringing your own cup works as well as a fee.” No

The extra cost has to sting a little: a loss, not a discount.

Real-world trials back this up: a small fee for a disposable cup changes behaviour far more than an equivalent discount for bringing your own. 7

05

From Principles to a Direction

Start the conversation with the most ambitious version in mind. Then get there in steps.

The three bundles are not alternatives to choose between. Bundle three is the destination: the most integrated and innovative version, and the one to keep in mind from the first conversation. Bundles one and two are the steps towards it. Bundle one is deliberately modest and can start almost immediately; each bundle after it adds more coordination and more of the four principles.

Assumption tested

AssumedStart with what is realistic, and see how far it gets.

Holds?No

InsteadStart the conversation with the most ambitious version in mind, so every smaller step is designed to lead there.

Bundle 1  ·  Proven foundation

Where to start the work

Start with what already works

Built entirely from things proven elsewhere: voluntary cup exchange schemes that individual cafés can join, a local fee (not a discount) on disposable cups, and a local rule that any disposable cup still in use must be genuinely compostable. It will not reach 90% on its own, but it builds the habits, evidence and goodwill the later bundles depend on.

Bundle 2  ·  Coupled, moderate risk

Shared regional infrastructure

A digital deposit system for reusable cups, built and run through Sydney's existing council to council waste partnerships. A small screen at the till shows today's community habit, such as how many people brought their own cup, alongside the fee already proven to shift behaviour. This is where the region starts acting together.

Bundle 3  ·  Boundary-pushing

Where to start the conversation

One region-wide reusable cup network

One digital deposit system for all of Greater Sydney. Tap to borrow a reusable cup at any participating café, tap to return it at any other, and the deposit comes back automatically. It works because it is backed by regional regulation, and because councils buy better cup materials together, which makes them cheaper than the disposable default. A public dashboard shows progress towards 2035, separate from the moment people pay.

What is still open before this becomes a plan

  • There is no Sydney-specific baseline count of cups yet. That is worth commissioning early.
  • The assumption behind Principle 3 has not been tested locally, only reasoned from evidence gathered elsewhere.
  • A Regional Organisation of Councils, or a similar cross-council body, would need to adopt the 2035 objective formally before it is more than an ambition.

Sources

  1. Australian Bureau of Statistics, Regional population, 2024–25 (released 31 March 2026). Greater Sydney: 5,638,830 people at 30 June 2025.
  2. City of Sydney, Council decision, Reusable Coffee Cup Scheme (13 May 2019): more than a billion disposable coffee cups used in Australia each year. See also MRA Consulting (2019): around one billion single-use cups sent to landfill each year. Regional estimate by TKD advisory, based on Greater Sydney's share of the national population.
  3. City of Sydney, Leave Nothing to Waste: Strategy and Action Plan 2017–2030.
  4. NSW Environment Protection Authority, Sydney landfill shortage.
  5. The Economist, on Australia's café sector (April 2024): some 95% of the country's 14,000 cafés are independently owned.
  6. NSW Government, NSW takes action to phase out single use plastics and harmful chemicals (9 November 2025); BeanScene (12 March 2026) on NSW Plastics Plan 2.0.
  7. World Cleanup Day on nudging; UK choice experiment (ScienceDirect); Hong Kong study (ScienceDirect).

Working on a problem that has resisted the usual fixes?

This example shows the structure TKD advisory brings to every engagement: define the problem, set an objective free of any solution, test the assumptions, and build from what remains. The same structure works for a program that is not landing, a strategy that is not holding, or a societal challenge your organisation has taken on.

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