If you want to change something, first you have to measure it. That's why the energy performance certificates you can now find on fridges, washing machines, cars and homes are so useful. They show us where we are and where we need to go.

They are not always as clear as they first appear. The rating system for fridges and freezers, for example, appears designed to bamboozle consumers. On the charts stuck to every device, A looks like the top category in a simple scale from A-G. But the most efficient fridge or freezer is actually an A++. An A should really be a C: the third-worst category. Ever since this system came into play, retailers have been passing off goods which are literally third rate to energy-conscious customers.

Perplexed? You haven't seen anything yet. Let me introduce you to the Kafkaesque world of the government's privatised data services.

In principle you can – or so the government has promised – immediately discover how energy-efficient a public building is. All you have to do is go online and look at the certificate (which in this case is called a Display Energy Certificate) which all such buildings – everything from government departments to theatres – of over 1,000 sq metres are now obliged to show. There's meant to be a hard copy visible in the building, and an electronic copy visible online. But, as James Berry of the Energy Saving Trust has pointed out to me, it doesn't quite work like that.

The government has outsourced the service to a company called Landmark Information Group. So you go to its website to perform what should be a quick and simple search. It says, "Click here to retrieve one of the below certificates or reports … Display Energy Certificate (DEC)". Having accepted some truly ridiculous terms and conditions you are then invited to enter the certificate's identification number.

There's just one snag: the only way to discover the identification number is to look at the certificate. But you can't look at the certificate unless you have the identification number. It's a perfect catch-22.

Hoping that I might be able to solve the problem by telephone, I rang Landmark this morning, and spoke to a friendly man called Colin. I told him I wanted an identification number for a Display Energy Certificate. This is what he said.

"We are not allowed to disclose that information."

"Why not?"

"Unfortunately, that's because of the way DCLG [the Department for Communities and Local Government] set up the contract. I can't really comment on why we're not allowed to release the information, because that's the DCLG's rules and regulations."

"So how do I get to see the certificates in your database?"

"You can view them if you've got the number."

"So how would I get the number?"

"I would imagine you'd probably struggle, to be honest."

Thanks to some heroic efforts by the BBC Open Secrets blog, there is finally a publicly available database of Display Energy Certificates, but you won't find it on Landmark's website.

It wouldn't be too difficult to devise a system that worked, would it? You would simply enter the name and address of the building and the certificate would appear. But that would carry the danger that the system might actually work, and voters would then be able to see how public money is being spent. Instead we have a system that is designed to be impossible to use, for which a private company is being paid by the taxpayer. Is this what open government looks like?

monbiot.com