Cardiff Metropolitan University
Halve the Half: A no/low-cost, data-driven approach to reducing cost and carbon
Finalist, Creating Impact
About
Delivered entirely through low/no-cost operational changes, Halve the Half is a data-driven initiative that targets energy waste occurring outside core operational hours. The initiative focuses on a simple, powerful insight: around half of energy consumption occurred outside core working hours, when buildings were largely empty. By using existing half-hourly meter data and building management systems, the University aligned operation with actual use, reducing waste without capital investment. Benchmarks indicated our estate was already ‘efficient’ before we started. Nevertheless, for the academic year 2025/26, the project has now reduced gas consumption by 34.5%, electricity by 11.2%, and water by 19.7% versus the academic year 2022/23, saving over GWh of energy, 16,000 m³ of water and over £2M to date.
Beyond operational impact, the initiative has supported academic engagement and behaviour change, while emerging partnerships across 12 universities and sector bodies are enabling wider adoption. By shifting focus from new infrastructure to better use of existing assets, Halve the Half offers a scalable, replicable pathway for institutions globally to reduce emissions
Top 3 learnings
- We uncovered hidden energy savings within an estate that was already deemed as efficient, with virtually no capital investments.
- We engaged students by turning energy use into meaningful, real-world learning and behaviour change.
- We built strong partnerships to scale impact and share a simple, replicable approach across the sector.
What it means to win
The chance to showcase this initiative which we believe can be replicated by other organisations to achieved national reduction in energy use.
Sustainable Development Goals
| 2026 | |
| Creating Impact | |
| Finalist, Wales | |
| Back to top |
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