Doctor Who’s TARDIS: an exclusive guide to the new changes

“It’s not a revamp - it's had an extension put in,” Chibnall laughed. “It’s blossoming!”

“The thing is with Doctor Who, you could keep building a TARDIS forever. So you can never do everything you want to do in the first year anyway.

“There's quite a few little finesses in terms of the TARDIS. It’s had a wash and brush up, which is really great.”

“It’s like a metaphor for the new series’ growth,” added star Jodie Whittaker.

“There are some things physically that may appear the same that are different, with different levels.”

Now, we can delve into some of those big changes right away - and speaking of different levels...

Upstairs Downstairs

The most eye-catching change to the TARDIS is that there are now stairs inside, leading up to a balcony that overlooks the main set.

“Some important things are gonna happen on those steps!” Chibnall teased.

“The staircase going up... we've got another level now compared to what we had last year,” added producer Nikki Wilson. “It’s all tweaks and improvements.”

And at the top of these stairs, there appears to be a door leading elsewhere in the TARDIS – and while on set it goes nowhere, the crew wouldn’t rule out that it could lead to different areas in the new series.

“I couldn’t possibly say…” said Wilson.

Raise the roof

The other big change to the Doctor’s time machine this year comes from above, with a new roof segment – including a second crystal pointing towards the central column crystal – added for the new series.

“There's a new roof – or maybe it was always there, and we just haven't tilted the camera up!” Chibnall said.

The new roof (which can be seen from below in the above photo) was created by incoming production designer Dafydd Shurmer, taking over from last year’s TARDIS creator Arwel Wyn Jones when he went to work on fellow BBC series Dracula.

“Dav worked with Arwel last year, and he was like 'Here's my wishlist of things, how I'd like to keep evolving the TARDIS.'” Chibnall said. “And oh, it's just great.”

A total smokescreen

Another innovation from Shurmer came with the TARDIS console, where he added special new screens for the Doctor and company to receive information and interact with the world outside.

However, these aren’t traditional monitors, instead projecting information onto a cloud of water vapour and creating an unusual visual effect. In the above image, while they're turned off, you can see the black boxes where the vapour is exuded on the upper left and right side connected to mesh pipes.

“These screens are new as well, yeah,” Wilson told us. “That was Dav's brainchild.

“Basically when it's on, steam comes out of here and images come from a little mini projector.”

In the previous series, the “screens” used by the characters were located facing out in the shifting, infinite walls and roundels of the TARDIS, but the crew fancied a change for the new series.

“Arwel's idea was not to have screen screens on the TARDIS, because he definitely wanted it to feel very organic,” Wilson said. “The screens last year were the ones on the sides, the big LED screens.”

“I really loved the screens in the roundels,” Chibnall added. “And we put them all over the place so they're very random, and I really love that in terms of the madness of the TARDIS.

“So they're still on the roundels as well - we've just got multiple screens.”

And in practical terms, according to Wilson the new water vapour screens made filming scenes in the TARDIS much easier.

“In terms of lining up shots, because there's so much distance, screens were cutaways rather than them being able to be part of the shots,” she explained.

“So this was Dav's idea to keep the kind of organic feel, but allow shots - you know, we've now got great shots this series where the image is projected and Jodie's looking through the image. Which gives us more variety, really.”

They were certainly a hit with one cast member anyway.

“I think Jodie loves these new screens,” Wilson continued.

“She loves moving all the time, she's quite frenetic as a performer and she likes to keep that pace up. So anything which allows her to keep her performance coming is a good thing.”

Though of course, Jodie's favourite aspect remains her handy custard cream dispenser...

The walls are closing in

When we spoke to Jones about his original TARDIS design, the idea of the shifting, endless walls representing the “Dimension” part of Time And Relative Dimensions In Space was important – and in this updated design, the crew were keen to enhance this concept once more.

“One thing that we wanted was to try and make it feel more infinite,” Wilson said, an effect which was achieved by adding extra “hexagon” lights and printed cloths of the wall design in previously dark areas.

And within the main TARDIS area, the space was really expanded by removing one of three movable, inner walls that had been part of the original design (and can be glimpsed in the above image with crystal growing up from the floor, and one of which can be seen to the left of the below image).

“There were three of them,” Wilson recounted. “And at one point the idea was that they might move in vision on their tracks. But when it came to it practically they were quite heavy to move and didn't move very well.

“And by having three of them, it actually made the set feel quite enclosed and quite small. So that was again one of Dav's things - by moving one of those and opening up the back and giving us that extra layer with the stairs...i t certainly feels bigger when you stand in it.

“And actually we've been able to get a lot of different angles on it. So I think onscreen it will feel bigger as well, which was always the intention.”

Making the TARDIS seem bigger on the inside? It'll never catch on...

Let there be lights

Now, we’re into the real nitty gritty – because one crucial change this year might not be noticed by viewers at home at all.

“Some of the changes are miniscule and you wouldn't even notice them,” Chibnall admitted.

You see, last year the crystal “fingers” around the TARDIS console, while golden-yellow in design and in person, didn’t look the right colour on camera, requiring them to by fixed laboriously in postproduction.

“We have redone all the LEDs inside these fingers, because last year, although you would walk in and they would look this colour, when you put them on camera they would turn pink,” Wilson said.

“I think it's something to do with how the blue and the orange light interacted. Basically, the orange LEDs weren't strong enough to counter that out.

"So our colourist, bless him, basically colour-corrected every single TARDIS scene last year. This year, happily, they look orange on camera.”

New blue ring lights can also be glimpsed on the TARDIS "fingers," and can be spotted in several images within this article.

The Doctor and the TARDIS

Of course, generally speaking these TARDIS changes aren’t huge, but they speak to the ever-evolving nature of both the set and Doctor Who as a whole – and to showrunner Chibnall, the two are totally entwined anyway.

“With Doctor Who, you can't do everything in the first year,” he told us. “You have to set yourself very specific targets.

“So it's like the TARDIS - we would have done all of these things in the first year had we had the budget and the time to do all those things.

“You have to keep moving and keep developing and keep evolving, I think, is the big headline.”

Was there ever a better mission statement for the TARDIS? Probably not…

Doctor Who returns to BBC One on Wednesday 1st January at 6:55pm