The COM-B Model: A Practical Framework for Sustainable Behaviour Change
We often talk about the need for change in sustainability, in organisations, and in how we work. But one of the biggest challenges remains the same: we can’t change what we don’t understand.
This is where behavioural science, and in particular the COM-B model, becomes so powerful.
What is the COM-B model?
The COM-B model was developed by Susan Michie, Maartje van Stralen, and Robert West (2011) as a simple but robust way to understand behaviour.
At its core, the model says that behaviour happens when three elements come together:
Capability: Do people have the skills, knowledge, or physical ability to act?
Opportunity: Does their environment (social and physical) make the behaviour easy or difficult?
Motivation: Do people want to act, and do their habits and emotions support that action?
If one of these elements is missing, behaviour change is unlikely to happen, even when intentions are strong.
Why COM-B matters for sustainability
Sustainability initiatives often rely on the assumption that awareness leads to action. If people understand the issue, surely they’ll change their behaviour.
In reality, it’s rarely that simple.
People may:
Care deeply about sustainability but lack time or tools
Want to change but work in environments that make it difficult
Understand what’s required but fall back into old habits
COM-B helps explain why this happens, and more importantly, how to design better solutions.
Moving beyond guesswork
Without a behavioural lens, organisations often rely on guesswork: more communication, more training, more reminders. Sometimes these help, but often they don’t address the real barrier.
By breaking behaviour down into Capability, Opportunity, and Motivation, COM-B allows teams to ask better questions:
Is this a skills issue or a system issue?
Are we asking people to change without adjusting the environment?
Are existing habits working against our goals?
This shift moves sustainability from good intentions to intentional design.
COM-B in practice
In the Behaviour Change for Sustainability course, COM-B is applied to real-world sustainability challenges, such as:
Shifting from paper-based to digital ways of working
Encouraging sustainable commuting choices
Reducing waste and improving resource use
Supporting people through organisational transitions
Rather than focusing on “getting people to comply”, the model helps design conditions where sustainable behaviours become easier, more natural, and more likely to stick.
Designing change that works
What makes COM-B especially valuable is its practicality. It doesn’t require deep academic knowledge or complex data, just curiosity about how people work and a willingness to design with humans in mind.
When organisations understand behaviour properly, they can:
Reduce friction
Improve engagement
Build more inclusive transitions
Create sustainability initiatives that last
Learning more
The COM-B model is one of the core frameworks explored in Behaviour Change for Sustainability, our new Udemy course focused on the human side of sustainability transformation.
For those looking to strengthen their ESG foundations alongside behaviour change, our Sustainability in Practice (SIP) course provides complementary tools, including AS-IS/TO-BE mapping, ESG concepts, and goal-setting frameworks.
📩 For team access or combined SIP + BCS bundles, reach out to projects@colectivo.ie.
A simple reminder
Behaviour change doesn’t fail because people don’t care. It fails when change isn’t designed with people in mind.
COM-B gives us a practical way to understand behaviour, and design sustainability initiatives that truly work.
