Greg Barker managed to give away the secret of their 100,000 tonne CO2 saving before even beginning his list. When he said success "was down to a team approach", we knew they'd taken the 10:10 philosophy to heart.
It's what 10:10 is all about. People working together, sharing problems, swapping tips - all working towards one goal. Understand this, and you're several steps closer to meeting your 10%. But with 300,000 civil servants involved, managing and channelling that enthusiasm was quite the feat of co-ordination.
The prospect of cutting emissions by 10 per cent was seen as a massive challenge for the civil service. This ambitious target went way beyond the ministries in Whitehall. It spanned 3,000 central government office buildings - everything from Whitehall headquarters to Jobcentre Plus Offices, HM Courts and Driving Test Centres.
They searched far and wide for inspiration, working with M&S, Kingfisher, Tesco, EDF and of course 10:10, to see how they could save.
Most 10:10ers probably won't have a direct line to the CEOs of Britain's biggest companies. But we think the key points Greg Barker outlined are a great guide for any organisation - not just the government.
Here are some examples of how their strategies have worked for other 10:10 organisations.
How we manage our buildings is key. Improving controls over energy consumption, making sure offices and server rooms aren't too cold nor too warm as well as shutting down buildings or floors over periods of low demand, which DECC did last Christmas, all had a big impact.
Investing in cost effective energy efficient equipment also pays off, whether through boiler upgrades or energy efficient lighting.
Redcar council hatched a five-year plan to upgrade boilers, lights, and even cars to cut carbon.
'Greening ICT' measures such as automatically powering down desktops when not in use and installing lower-energy monitors.
The Guardian told us about their IT workshop, where they got the lowdown on the how to stay CO2 savvy with computers.
Making better use of office space by concentrating accommodation in more energy-efficient buildings.
Land Securities adopted a similar strategy, consolidating their office space from two buildings to one even as the business grew.
And finally, perhaps most importantly, behaviour change. You have to have the buy in from everyone in the organisation from top to bottom. By encouraging staff to take simple actions to reduce their own carbon footprint, such as turning off lights and equipment when not needed. Real time energy displays were also installed in 19 Whitehall HQs and on our websites leaving us no room to hide.
The golden rule! Whether it's weaving climate change into the curriculum at Church Cowley St James school in Oxford or HCR's fresh approach to environmental training, making sure that change comes from the bottom to the top is the most important point of all.
Commendably, and in line with their "team effort" ethos, ministers were quick to credit the facilities managers and civil service staff that made the changes happen on the ground. Now the low hanging fruit is gone, they'll be continuing their carbon-cutting efforts with a view to hitting 25% off by 2015.
It's easy to feel cynical when the government announces a new target, but by taking their first 10% seriously and delivering the goods, they've provided further proof that large organisations can bring about change fast. As Angela said in her recent blog, what they've done is genuinely impressive, but the next steps are crucial.
Long-term targets are important, but it's what we can achieve in the near term that really matters. With your help we'll hold the government to that standard, making sure ministers not only keep up the ambition in cutting the government's own emissions, but also pass policies to ensure that low-carbon living and working is never harder than it needs to be.
This means getting the Daylight Saving Bill through parliament, securing a simple, fair carbon reporting system for companies, exorcising the devil from the details of the Green Deal, and using 10:10 success stories to inject optimism and ambition into the political debate around climate change.
There's a long way to go, but this is a hell of a first step.