What is a house for? Two opposing answers to that question are battling it out in London right now. The first is pedestrian, traditional: it says that a house is fundamentally a home. The other is newer and far more sophisticated: it argues that a London house is now an international asset, to be bought, sold or held by speculators from across the world.

The Candy brothers engage in complicated financial planning to ensure they pay as little tax as possible to this country

One Hyde Park is the glass and steel embodiment of the second argument. London’s most expensive block, where flats go for up to £140m apiece, it juts out of Knightsbridge. Qatari money paid for its building. Russians, Kazakhs, and Ukrainians have bought apartments there – although how many of them live there is up for debate. A 2011 investigation by our sister paper the Observer revealed that only nine of the 62 homes then sold in the block were registered for council tax – and five of those were paying the half-price reduced levy for second homes. The following year, journalists at the Guardian found that 80% of the residences had been bought by offshore firms based in the British Virgin Islands.

Some might look at One Hyde Park and see a temple to wealth, an enclave of the super-rich. They’re partly right – but the building is also a state of the art financial instrument, bought tax-efficiently by some of the world’s biggest holders of flight capital. Allow me to say this very gently, so as not to give the Guardian’s lawyers palpitations, but not all the money invested in that building may have been earned in the sense normally understood by earthlings such as you and me.

Revealed: the video the Candy brothers' tax adviser didn't want you to see Read more

It’s against that background that we should read the latest revelations about Christian Candy of One Hyde Park. As today’s story shows, who Candy is depends entirely on whether you believe his advisers – or the words that spring from his own mouth and those of his closest colleagues. So he talks like one of the property developers for the luxury flats – but was not one of the property developers, no sir. He is a UK tax exile, who has apparently been coming to the UK every week for the past five years. He appeared to help pick the contractors for the project, like a property developer would – but was not a property developer. Which version of events one is told seems to depend rather a lot on whether one might have something to do with Her Majesty’s Revenue and Customs.

The reason Christian Candy should have chosen his words very carefully is because he heads another part of the brothers’ empire, the part based in the tax haven of Guernsey – the most profitable bit to do with developing and flogging properties. Elder brother Nick Candy supposedly does the interior design and project management, based in the UK. Except that, as the unedited video obtained by the Guardian suggests, the roles are not so cut and dried as all that.

One Hyde Park is just a block of flats, supposedly a set of homes. But it is also a tax-efficient financial instrument, developed and managed by a couple of brothers who are themselves engaged in complicated financial planning to ensure they pay as little tax as possible to this country. Even though they rely on British law and order to protect their property and the deals made on it. Even though they studied at British universities – at a time when British students paid no tuition fees (perhaps now may be a good time to remind ourselves that Christian Candy named his twins Isabella Monaco Evanthia and Cayman Charles Wolf).

The world the Candy brothers are part of, and the world that they sell to their clients in the wealthiest 0.1%, is a world of opting out. Opting out of the society one is part of, opting out of paying one’s taxes to the UK Treasury. I visited One Hyde Park in its early days. Once past the top-hatted doorman, I went up eight floors in a glass lift, then into a flat decorated with statues of big cats and with a verandah that would enable its owner to breakfast above Knightsbridge. The publicist pointed out the marble worktops in the “family” kitchen, and then the second kitchen behind it where one’s staff would do the actual cooking. There was round-the-clock room service, she explained: “When you’re flying back to London, you just ring ahead and ask for someone to turn down your bed.”

It struck me as a pied a terre for a private-jet capitalists, and it would have bothered me less were it not in a city where over a quarter of a million households are waiting for a council flat. One Hyde Park is in the borough of Westminster, where half the households waiting for social housing are now homeless. Public-housing provision in Westminster is so thin that the council is now infamous for dumping tenants in need of an emergency home into outer London.

As I say, there are two versions of what a house is for now at war in the capital. I still have the old-fashioned, corduroy answer that a house is a home. But that idea is being driven out by the likes of One Hyde Park, and all its sophistication.