Thomas Sutcliffe: Space - architecture's final frontier

'All these structures make new room in a crowded world, and they make it for us, for anyone who wants to pitch up'

If you want a vivid study in architectural contrasts, you can't do much better than fly from San Francisco airport to Heathrow. At one end you have San Francisco's new international terminal, which – notwithstanding the seismic unpredictability of the ground it stands on – has to be one of the most soothing gateways to flight anywhere in the world, an airy cathedral of transit filled with shops so tasteful and understated that the description "merchandising concession" seems almost blasphemous.

If you have no dollars to spend, you can wander across the acres of polished terrazzo to visit the airport library, watch a beguiling video installation (just one of numerous permanent artworks dotted about the building) or visit a Fabergé quality geology display on loan from the California Academy of Sciences.

And everywhere you look there is empty space – the kind of gratuitous vacancy that has become a modern hallmark of privilege. The space above your head has not been carved up into rental units – it has been left open so that the sunshine falling through the arched skylights high above can reach you, falling equally on First, Business and Economy.

And then, after the infantile suspension of flight, you come back to earth with a bump, back to the mercantile shanty town of Heathrow – that grubby, money-grubbing portal to the New Britain. It is cramped, it is dog-eared and it is incoherent – a sorry capitulation to the powers of chain retail and commercial yield. It appears – and perhaps this is an effect of jet lag – both gloomily jaundiced and glaring, a clutter of competing interests in which those of the passengers are almost an afterthought. Heathrow hasn't, in truth, been built at all – it has just accreted over the years, desperately trying to keep up with rising demand – an architectural palimpsest of make-do-and-mend.

And with that contrast fresh in the mind it was gratifying to find that Heathrow had made it on to the Today programme's shortlist of Britain's most loathed buildings, part of an assay of contemporary architectural taste prompted by the millennium building boom. Heathrow is currently running third in the popular demolition wish-list, behind the Tricorn centre in Portsmouth (another Sixties consumer rat-maze) and Buckingham Palace – which has a staggering lead of just under 70 per cent of the online votes.

Quite what Buckingham Palace has done to earn such hatred I don't know – the building itself is a bit of a botch job, admittedly, but I suspect that this is actually a rogue result – a tell-tale spurt of republicanism exploiting a convenient outlet rather than a genuine expression of aesthetic distaste. Elsewhere, though, it is possible to see a pattern in the votes so far – and it is one that confirms the doleful lesson of that flight from San Francisco to London.

On the face of it, the shortlist of loved buildings looks pretty varied. Durham Cathedral leads the field by almost as large a margin as Buckingham Palace in the other category, so there's no clear demarcation between heritage and modernity being expressed here. When Prince Charles made his ineffably dim-witted contribution to architectural debate a few years ago, he did seem to give voice to a public prejudice – old buildings good, modern buildings bad. But that simplistic response (which always forgets that old buildings had to have been modern buildings once) isn't really detectable in the Today shortlist.

Besides Durham Cathedral, that list consists of three very recent buildings (the Eden Project in Cornwall, Tate Modern in London and Stansted Airport) and one from the glory days of shuttered concrete – the National Theatre. This last is a rogue result too, I think – 99 online voters having been stung into a defence of Denys Lasdun's theatrical gun emplacement by the 112 people who nominated it for the wrecking ball and thus earned it a place on the most-hated list. The Millennium Wheel, which would otherwise surely have been jostling for pole position, was apparently excluded from the running after some theological debate about the exact nature of a building.

Some might see this apparent triumph of modernity as evidence of a new public sophistication about architecture, but I'm not convinced we're quite there yet, even if matters are improving. It's no surprise that one of the best of the millennium projects – Caruso St John's new art gallery in Walsall – didn't make it on to the short-list, despite early-morning electioneering by several expert witnesses. The truth is that Walsall is a subtle and complex building, and while complex articulation may feed the souls of architecture students and practitioners, the public wants something more immediate in its delivery of pleasure.

The shortlist suggests that the public wants its buildings legible and that the reading age should not be too demanding. And, for all their technological sophistication and fineness of detail, several of these are Janet-and-John structures – whether it's the giant bubble raft of Nicholas Grimshaw's Eden Centre or the cinematic splendour of the entrance to Tate Modern. You don't have to subscribe to Architects' Journal or Blueprint to "get" what these buildings are about.

What they're about – at least in their appeal to ordinary people – is enclosed space in vast masses. In a largely secular age Durham can still move its visitors with that most ancient architectural trick – the creation of a place sequestered and set apart from worldly considerations. In an age where every square foot of ground has its price and every vertical foot of headroom, too, this is a powerful short cut to a sense of the sublime.

It isn't Giles Gilbert Scott's external massing that wins over the visitors to Tate Modern (though it has now squarely swung back into fashion) nor Herzog and DeMeuron's display-case additions to the roofline – it is that vast emptied nave, which eloquently announces that we have left a world of mercantile values behind. It is, from any perspective but an aesthetic one, a breathtaking and beautiful waste of space and at some level everyone entering the building can appreciate that and relish the ability to stretch their imaginations.

In similar fashion the Eden Project – as its very name implies – takes a practical building (a greenhouse) and inflates it until it achieves an almost mythic scale. All these structures (the National Theatre is a rogue finding, remember) make new room in a crowded world and they make it for us, for anyone who wants to pitch up. Even Norman Foster's Stansted building luxuriates in its extravagance and airiness – though there are signs that corporate greed is already spoiling his carefully planned blankness – as if affronted by the declined opportunities for profit.

By contrast the buildings on the most-hated shortlist are models of yield-per-acre efficiency, dedicated to the principle of squeezing as much in as possible. They aren't legible, in most cases, because they're a kind of overlapping collage of different texts, all clamorous and self-interested. And the one exception to this rule – Buckingham Palace – is out of bounds anyway, admission to its imposing spaces granted not as a right but as a grudging and limited concession to changing public sentiment. What all these buildings fail to give us, in different ways, is what all the popular buildings triumphantly deliver – a kind of sublime hollowness. It's never been a conventional term of praise for a work of art, but in the best sense these buildings are empty and all the evidence is that we love them for it.

t.sutcliffe@independent.co.uk