“Like the architecture?” a Terminal 5 employee called out to me as I stood taking this photo. “Yes,” I replied, “absolutely.” “I hate it,” chipped in a passer-by, hurrying up an escalator. “That’s because you work here,” said the employee, firing me a knowing smile.

I felt a bit flattered. Not only had I been hailed by a member of staff who for once was not demanding I put away my camera or else chase me off the premises, I had also been made party to a bit of staff-room bitching. And I didn’t even work here. I had an “in”! And at an airport, a place where I usually feel thoroughly “out”!

To bond with a stranger over a slice of modern architecture is a rare treat. To do so at Heathrow Terminal 5, which trumpets its contemporary wares from every crevice, made me a bit dazed. Or to be accurate, even more dazed, because I’d felt a little out-of-sorts from the moment I’d arrived.

Despite offering plenty of architecture to admire, this terminus-in-a-terminal stretches every sinew to make you not want to loiter.

Its glittering speck-free platforms and vast hushed walkways, not to mention its platoon of notices all urging you to move on and go somewhere else, conspire to make the spectator – as opposed to the traveller – feel rather uneasy.

This isn’t an environment conceived for contemplation. If you must wait, the atmosphere implies, do it sitting in a carriage, or up in the airport terminal itself. To stand still is to stand everyone else to attention.

Which is a shame, as the best way to appreciate the elegance of the station is to do just that. And not just stand still, but look up, for this is a majestic soaring construction that scoops light from the surface and deposits it dozens of metres below the ground, while simultaneously doing the same in reverse with people.

Going up…

Arriving here after 45 minutes on the Underground is to emerge from a dark warren of horizontals into a rather eerie but enticing forest of verticals.

The station isn’t as magnificent a modern-day cathedral as some of those along the Jubilee line extension, such as Westminster and Canary Wharf. But it’s scale is just as persuasive as its design, it has a church-like enforced calm, plus there’s a curiosity value that repays – if you can manage it – a non-suspicious linger.

Especially when the Heathrow Express is just through the window:

This was the first time I had been anywhere near Heathrow for years – and the first time ever I had been to Terminal 5.

Along with not really knowing what to expect, I’d had to deal with the rising anxiety of setting foot in one of the world’s most scrutinised airports with absolutely no intention of getting on a plane or meeting people who had just got off one. Ripe for scrutiny, in other words.

Which is precisely what happened, though not in the form of an interrogation, more a jovial chat. Nonetheless after about 20 minutes I wanted to leave. I had a hankering for fresh air and the sight of a brick.

Besides, all those semiotics were doing my head in. Now there’s a phrase I haven’t needed to use since back at university.