Not long ago, sustainability leaders were the rock stars of the boardroom. Now the team is smaller, the questions are sharper and the agenda slot keeps shrinking. Nobody gets excited about ESOS. Ben Hart, ESOS Lead Assessor at Hyphora Consulting, thinks that's exactly why it deserves a second look.

Why did I choose this work?

After studying Environmental Science in the mid-00s, I left Sussex University in 2006 with a choice. Research climate change and find out how bad it would get or try to do something about it. I chose to do something.

I'd spent previous summers working on my stepdad's building sites in Suffolk, so property felt a natural fit. I initially audited homes across London and supported homeowners to ‘green’ their homes (chimney balloons were a favourite), then joined an energy services company that guaranteed its energy and cost savings from the renewable and energy efficiency projects we installed. That taught me the rule I still work by: until the kit is in the building, it's all just a paper exercise.

Why does the job feel so hard right now?

Let's be honest. Leading sustainability today is one of the hardest jobs in the business. Teams are being shrunk. Climate is slipping down the agenda. We're seeing more green hushing. And the board still wants proof of impact well beyond carbon. We’re past the days of projects happening because they are the right thing to do, they need to make business sense.

Recently much of the role has become data collection and report writing, and I believe with new AI tools a lot of that work is going to go away. But that’s a good thing - most people didn't come into this work to write reports. They came in because they care, and they want to have impact.

How did ESOS end up in a drawer?

When ESOS started in 2015, around 10,000 organisations had to comply and there were about 300 lead assessors in the country. Electricity was around 10p a kilowatt hour and gas often 2p. Nothing required organisations to report or act on what we found, kit was expensive and the business case often didn’t stack up against other priorities. 

So, most reports went in a folder (or a work drawer – remember them!) and were forgotten. Where companies did act, they signed off the low-hanging fruit. The LED upgrade got done. Everything else waited.

So, what's different this time?

Energy costs have risen sharply, and CFOs are more receptive than in previous rounds. Phase 4 asks you to report what you’ve implemented from your Phase 3 action plan, the savings achieved, and why any committed measures weren’t delivered. And the cost of getting to a credible business case has dropped dramatically.

ESOS also must be signed off by a board director. When board time is scarce, that's a guaranteed seat at the table. I think could be the biggest opportunity heads of sustainability have in the next 12 months to get their agenda back up there and get moving on creating that impact.

How do you walk in with confidence?

Get right to the top. Take your plan to the CFO: here's a compliance activity we must do, and here's how we turn it into serious savings and future resilience. At the very least, find a board-level champion.

Then respect their time. Make sure your message is tight, your math is clear, and you have answers to the questions they'll inevitably ask.

And think in programmes. Finance directors want two-to-three-year paybacks, so only the quick individual wins get signed off. But merge a two-year payback on LED lighting upgrades with a ten-year payback on solar and you might land at seven. Do it once, do it well.

Where does the technology help?

A decade ago, I had a team of eight engineers processing data and writing reports. AI agents can now do much of that, with a lead assessor signing off. Optimisation work that took us weeks or months of manual work, OptimiseAI can now do in days.

Someone with knowledge and experience still needs to  understand the buildings. We still need human judgement to make sure what we’re proposing is right, but a small team can now spend its time where it counts.

What happens after the kit goes in?

With the very best will in the world, once you optimise a building and then leave it, it will drift. Settings change. Equipment gets replaced. Controls get put into hand.

At the University of Winchester, I helped secure £3.2 million of Salix funding to take 11 buildings off the gas grid. We still meet quarterly, and we've caught things like a boiler left in hand, pushing out heat the heat pumps should be providing. That's why the savings hold: around 41% reduction on gas, and almost £120,000 saved last year.

Live data turns ESOS from a document every four years into a programme that keeps proving itself. When Phase 4 asks what you've delivered, you have the evidence.

What should you do before Christmas?

Most people won't be thinking about ESOS yet. If you are, you're ahead. You can't completely sign it off until 1 January, because you need the 31 December data. But you can build your audit plan now and deliver audits before Christmas. Wrap up compliance in January and February, then get your impact programme into budgets before the March year end.

Leave it to late 2027 and every lead assessor I know will be flat out.

And if you remember one thing?

I measure my career impact in tonnes saved. So far, it's around 23,500 tonnes of carbon a year from the projects I've worked on. With Hyphora, I want to multiply that tenfold.

ESOS is your biggest opportunity right now. It's a compliance task you can turn into huge impact, if it's done right. The cost of acting has never been lower. Grab it with both hands.

Ben has spent 18 years moving energy savings off paper and into buildings. If you'd like a second pair of eyes on your ESOS plan, he's happy to talk. So are we. OptimiseAI gives you live data on every building, so the numbers you take to the board are numbers you can stand behind.