To describe my relationship with the staircase at the Denys Lasdun-designed Institute of Education as an obsession would be going a bit far. Yet I’ve written about it, describing it as ‘London’s Most Thrilling Staircase‘, and would always look out for it, as if an old friend, whenever passing through the vicinity. I’d slow down as I walked past, in order to enjoy its angles revealing, unfolding and revolving, allowing it to repeatedly frame the surrounding IoE megastructure, the muscular Senate House and the rest of the Bloomsbury campus.

That’s 17000 kilometres away from me now. The new arrival in the city often appears to see a feature from his previous home, shoe-horning an entirely new structure into a familiar shape willed from his memory. The first white arrivals in Sydney, 219 years ago, described this utterly alien new terrain as ‘a deer park’, as if they’d sailed round the world to discover an impossibly large Kentish garden, that is before they tried to plant anything remotely Kentish.

As for me, I’ve been in Sydney just over a month and I’ve seen a cracking concrete staircase.

Due to the vagaries of long-distance relocation, we temporarily find ourselves walking past the University of Technology, Sydney, at no. 1 Broadway, Ultimo, on an almost daily basis. The UTS building is a brutal slab – I mean that in the good sense, of béton brut, or ‘raw concrete’ – with a sturdy 28-floor tower providing a handy landmark for wayfinding, beckoning people out of the eastern edge of city centre. Even in Sydney’s light it’s not pretty but it is striking. At its base is a wide podium, uncomfortably windswept, but at the base of that, there’s a usefully wide tiled courtyard leading into a spacious interior reminiscent of the Barbican.

It’s tricky to find out who designed it – the internet offers up only the anonymous "NSW Government Architect". As is often the case with brutalist architecture, it’s been voted its city’s ugliest structure. And as is also often the case, it’s not all that bad.

I don’t know enough about the building to want to say any more about it. But, quietly tucked away off to one side, a parasitical little structure catches my eye. A simple external concrete staircase. Adjoining the podium level at its top, and leading from the courtyard at its base, it’s a beautiful, elongated vertical cube, slabs of concrete appearing to carve repeating angled grooves on the outside, echoing the ascent of stairs on the inside.

The interior is pleasantly cool on this already hot spring day, deep pools of shadow falling across the concrete, with angles cut in dazzling white stripes emblazoned by the sun. As you climb, the blue sky begins to pierce through, and then slowly fill the space above, as angled fragments of the city can be viewed through the slits in-between the concrete shell at eye-level.

On the way down, I find an old man having a quiet cigarette, sitting on the stairs, watching as the courtyard fills with graduating students, posing for pictures taken by proud parents, theatrically tossing their mortarboards into the air.

As with much great architecture, even when as nondescript as this, it frames the city around it, depicting it as a series of jump-cut fragments, buildings twisting and unfolding, in and out of sight. And as with all things set against this overwhelming blue sky, there’s a momentary duck-rabbit figure-ground reversal – the blue of the sky suddenly appears to be the object, the staircase the negative space surrounding. The sequence of photographs above suggests a new construction, the white line-breaks occasionally flowing in and out of the white sun bouncing off the concrete edges in the images – a dazzle-ship camouflage disguising its actual shape. Elsewhere, the geometric slashes in the side of the concrete recall the swoosh of some imaginary logo or device. Looking up, to the top, and how it adjoins the podium, the modular design is clear – it looks like a 2=pin plug, suctioned by the body of the UTS building.

If you actually compare to the IoE staircase and perform the equivalent of a conceptual squint, it’s as if Lasdun’s has been carefully collapsed, concertina-style, at 45 degrees, sliding together into a more compact form, as if for transit. You might well think "Bloody hell man it’s only a staircase." Me, I think I’ve folded up Lasdun’s staircase and taken it with me.