Sir Howard Davies will set out his plans for the commission into UK airport expansion today. "Our preparatory work will help the next government to have 'a flying start' on the decision on airport capacity in south-east England," he told the Today programme this morning. But architects have already been busy.

Exactly a year ago today, Norman Foster unveiled his momentous plans for a new airport hub on the Isle of Grain in the Thames estuary. It was shown from the air as a glowing mothership, from which swooshing lines of high-speed rail extended into the distance, like benevolent umbilical cords channelling the energy of this vast infrastructure project into the UK economy. The lens flare of the low setting sun cast an alluring golden glow over the scene. It may have been the result of a self-funded, four-year-long research project, but the singular power of this one image was enough to seduce the target audience.

"This is a moment for greatness," declared Boris Johnson, ever one for seizing on the political capital of a vanity project. "It is a moment for bravery."

The significance of this strange sequence of events was not lost on architects. Trained as boundless visionaries, they are a species whose ears prick up at calls for greatness and bravery. Such moments provide outlets for pent-up desires to conjure futuristic megaprojects, a chance to relive student days of speculative dreaming, with the power of Photoshop readily at hand.

"We need to recapture the foresight and political courage of our 19th-century forebears," proclaimed Foster, a call to arms that was not to fall on deaf ears.

Norman Foster's proposal for an airport hub on the Isle of Grain in the Thames estuary

Since the Davies commission on aviation was announced in September this year, there has been a remarkable spate of similar proposals, to the extent that there is barely an airport left in the south-east that has not been furnished with a futuristic twilight vision of multiple runways and attendant glowing arteries.

The American firm Gensler was one of the first to catch on, cranking up the sci-fi mood a few notches with a proposed alien spaceship of an airport, a series of blobs floating in the Thames estuary.

"We don't need tiny, incremental improvements," trumpeted Gensler's design director, Chris Johnson, following in Foster's declamatory footsteps. "We need a bold idea."

Its proposal, named London Britannia, would feature up to six 5km runways, open 24 hours a day, capable of handling 150 million passengers a year from more than 400 gates. Accessed by jetfoil from the mainland, this island hub would apparently avoid the usual constraints of "traditional, land-locked airports".

Gensler is no stranger to ill-fated plans for floating globular structures: its London River Park idea, mooted last year to collective dismay, would have seen the north bank of the Thames lined with silvery pods for corporate entertainment. Thankfully it appears to have been quietly abandoned.

Not to be outdone by his former employer, Ken Shuttleworth (AKA "Ken the Pen, designer of the Gherkin") recently revealed plans for a four-runway future for Stansted, potentially connected to Heathrow by a Crossrail extension to form a dual mega-hub. His practice Make's proposal has yet to be finalised, but that has not stopped it from releasing a now-familiar vision, rendered at night from a plane's eye view, of the airport looped with new runways and emitting a misty glow that conveniently obscures any detail.

Make's proposal for runway expansion at Stansted airport

"Stansted has very good transport links in terms of the M11 and railway and fairly low population density," said Shuttleworth. "It's all built on land, and it's also closer in real terms to the majority of people in the UK, than to London."

Stuart Blower, partner in charge of the project at Make, sounded less enthusiastic, describing the Stansted expansion to the FT as "perhaps the least worst of the options" for increasing capacity in the south-east.

Points for the most romantic rendering of all must surely go to Weston Williamson Architects. This infrastructure specialist has surpassed itself with a dreamy apparition of Luton airport as a space-age landing pad, surrounded by glowing red roads and shimmering blue railway lines, with multiple cosmic rays emanating from its runways.

Weston Williamson's proposal for an expanded Luton airport

"We think the debate about the future of air transport in the UK needs to be broadened further than a nice diagram by Fosters and the pragmatism of expanding Heathrow," said the practice's director, Rob Naybour.

"If you programmed a computer to position the best place for a world-class airport, it would choose Luton. It might actually choose Milton Keynes, but Luton has an international airport already."

With this glut of rival airport projects, each seemingly less worked out than the last, a brilliant spoof appeared on the internet last week proclaiming the arrival of London-Southend Pier International Airport, heralded as "the world's first pier-based-international-airport".

A spoof proposal by 'Make It Architects', the London-Southend Pier International Airport

"Make It Architects believe that this revolutionary solution to the UK's aviation capacity issue could become a blueprint for airport expansion across the country," announces the website, "and are already drawing up a proposal for Blackpool, or Blackpool-London North International Airport, as it will be renamed."

Any decision on the future of south-east airport expansion has been deferred until 2015, providing three more years for architects to perfect their atmospheric rendering skills in a bid for more consultancy work. I look forward to seeing what else will emerge from this surreal battle of romantic representation.