In our 2025 lighting design report, Light in Focus, we make a lot of big and bold statements. However one of the most meaningful is our very serious commitment to circularity and reduce waste where we can control it:
Using the TM66 methodology, we set ourselves the target of achieving a 2.0 and above score as a project wide average on all our projects. The overriding goal was to redefine the design process, while our immediate aim was to gather data and explore a new way of working.
What is TM66?
TM66 was developed by The Lighting Industry Association (LIA) and Chartered Institution of Building Services Engineers (CIBSE).
Circularity is achieved by ensuring that products are designed, manufactured, and managed in a way that minimises environmental impact, optimises resource use, and enables effective recycling or reuse. TM66 and the assurance scheme provides a robust framework that allows lighting manufacturers to demonstrate the sustainability and circularity of their products through independent verification.
We have reviewed our data, the results tell us we have not done enough to affect change. Our London team reached the initial threshold without really changing the way that they design.
Does this mean that our schemes were already circular?
More likely that our threshold wasn’t high enough and that we need to do more to make a difference.
So, what are we doing about this?
We are rolling out the TM66 metric out across all our global offices.
Our objective is to make designing to a minimum level of circularity a consistent standard across every single Nulty project. We will be increasing the threshold for Nulty London. The London team will raise the TM66 threshold further by introducing a minimum score and increasing the target score of upwards from 2.0.
It is important that we use TM66 to influence the way that we design. Whether that means specifying fewer products overall or filtering out those that do not score well for circularity, we want to challenge the process and drive the industry towards more effective practices.
Image: Nulty’s lighting design for Energy Revolution: The Adani Green Energy Gallery at the Science Museum reinforces the aspiration set by The Science Museum Group and Unknown Works to employ circular economy principles in the design process.
Nulty is committed to circularity by embedding CIBSE’s TM66 into our specification process. Every luminaire on every project must be assessed using the CEAM-Make or CEAM-Specify tools. No exceptions.
We understand that this isn’t always easy. Deadlines are tight and we’re all busy. But circularity isn’t optional – we need transparency not ambiguity.
Going forward, if a manufacturer can’t (or won’t) provide the required data, they won’t make it onto our specs.
If you can’t give us assurance in your products, you no longer meet our criteria for circularity.
We hope the rest of our industry and design partners do their part.
You can learn more about how we embedded circularity into our project at The Science Museum here.
