EXCLUSIVE | Join Australian Business Traveller as we go below decks on a tour of Airbus’ innovative design concept for putting passenger lounges and bunk beds into an aircraft's cargo hold.

I’m at the sprawling Airbus headquarters at Toulouse, France, but visiting a part of it which very few people see: the cabin mock-up centre where airline executives come to decide on fitting out their new Airbus jets.

Those decisions are aided by full-size cabin mock-ups of the Airbus commercial jet family, from the nimble single-aisle Airbus A320neo (above) to the mighty A380 superjumbo (below).

But tucked away out of sight, down two levels of gantry stairs in this already high-security building, is what may be the next leap forward in cabin design for ultra-long range aircraft: custom-designed 'lower deck modules' which transform part of the cargo hold into a sky-high version of a railway sleeper berth.

Airbus is pitching the concept at airlines making ultra-long flights, as a way to provide additional space for passengers without taking away from the precious real estate of the main cabin.

Upstairs, downstairs…

After the flight takes off and reaches cruising altitude, you’d descend a set of stairs located near the front of the upper deck.

This takes you into a customised crib built to the same footprint as a standard aircraft cargo container.

In this mock-up, Airbus has stitched together several such modules to create a single flowing space.

The first area contains six single bunk beds, with steps so that passengers can climb to the upper bunk.

This is what Qantas CEO Alan Joyce has suggested could be "a new class" of travel with "berths like on a train" for the globe-striding jets of the airline's ambitious Project Sunrise, which aims to link Sydney and Melbourne non-stop to London and New York by 2022.

(That said, the current design doesn’t permit these spaces to be occupied during take-off and landing. Passengers would pay for both a regular seat upstairs – perhaps in premium economy or economy – and a bulk bed below.)

Several shelves provide space for cabin bags and other personal items.

A lower-deck lounge?

Past the bunk beds are modules shaped more around seating to provide travellers with a different, more social space.

A sliding door opens to reveal what is ostensibly a meeting room above the clouds...

... with banquette seating for nine people wrapping around a conference table.

This is just one take on what could be offered as a more open exclusive lounge for business class and first class flyers, as Airbus suggests in this sketch.

A more casual version is this corner area…

… while there’s also a small refreshment bar which Airbus has dressed up with drinks.

This more Spartan space, dressed with only a handful of chairs, allows the Airbus boffins and airline executives to toss around other ways in which a passenger module could be used.

Possibilities already on the blackboard include a family room...

... and even a medical facility.

Max headroom

I'm not an overly tall guy – at 1.75 metres, I'm bang on average for the European male – but with the ceiling height around 1.6 metres, moving around this below-decks space requires me to be crouched over and scuttle along with measured steps.

The straight lines, flat surfaces and overwhelming whiteness of the space feels as if I’m in a submarine designed by Ikea.

This in turn makes me ponder how a good designer – individuals such as Qantas’ David Caon or Cathay Pacific’s Ilse Crawford, or the teams at PriestmanGoode or JPA Design – could use colours, materials, textures and gentle lighting to transform this blank palette into a cosy den.

There’s still plenty to be done before Airbus can bring this concept to market around 2020, but the company is already pitching the idea to Qantas in the Project Sunrise bidding war, which will see the long-legged A350ULR going up against the next-generation Boeing 777X.