Joel Wilson, the Executive Producer on Gap Year, explains how the show was developed.

Where did you start as far as developing the characters?

Jamie [Campbell] and I had had the idea of young people travelling sometime before we'd met Tom [Basden] about it, but Tom had separately had an idea and he had spent a lot of time in China. He had the idea of sending the characters to China. That's how the idea came about in the first place, Tom was fundamental in inventing those characters.

When did you first start talking to Tom about the show?

We first started talking to Tom about the show about two years ago; Jamie and I had had an idea that we had been developing for a while about sending a group of young people travelling. Tom had separately had another idea about people travelling around China. We let our powers combine, as it were, and we started thrashing ideas around and then Tom went off a started to cook up the series.

As the Asian element of this came from Tom's experiences, what did that mean to you as producers?

The biggest challenge for us as producers was shooting in China, which was very tricky to get off the ground: it's a very different culture and has a different way of working. These aren't always compatible with the ways we need to work in the UK.

Practically you took on something you've never taken on before.

Yes, it was a backbreaking task for the cast and crew, Tim [Whitby] the producer did an incredible job of keeping every together and sane (just about) and keep us on budget (just about). We filmed in Vietnam, Malaysia, China, Nepal, Thailand, all over. That's no mean feat and they did a fantastic job - filming in jungles, beaches (that was nicer), filming in Shanghai and Beijing. So that was the biggest challenge for the shoot, compared to other shoots, was moving people around and equipment around and making sure we stayed on track to do that. We are very grateful for Tim and all his hard work.

You were shooting in extraordinary locations, which are stunning, but you are also having to shoot quite tiny mundane tiffs in front of such an extraordinary back drop. That is a hard balance to find?

It is but that was always at the absolute heart of what we wanted to achieve, in that we wanted it to be a series about ordinary relationships and quite common problems and situations that people deal with in any relationship when you are young, and also when you are old. But played out in front of these really dramatic backdrops.

So, one of the earlier references we had, it was an Indian reference, two people arguing about using each other's toothbrushes in front of the Taj Mahal. Having the Taj Mahal out of focus in the background. When we met with Tom he was very eager to set it in China and so we quickly moved the idea to Asia. But, I think we've really kept to that idea, we are shooting in these really beautiful locations but the arguments, conversations and situations that are going on, in many ways, could occur anywhere. That's part of the fun of the show I think.

What is the trick of developing the authenticity of the characters?

Tom came to the development process with some very specific ideas about characters, we discussed those and worked through them, we evolved through that process and Tom went away and started to write scripts and again the characters evolved into three dimensional beings on paper. And then when you start to cast, of course, those assumptions that you had in your head are challenged in really exciting and useful ways.

Quite a lot of the characters developed after casting quite heavily, and were influenced strongly by the characters of the actors. None of the actors are playing themselves, by any stretch of the imagination, they are playing characters that they have invented along with Tom. But it is interesting when a character discovers a part that you start to discover things about the character that you maybe hadn't before, in some ways you might find it awkward at first but usually by the end of it you really learn something about the character and you develop in a really positive way. That's part of the fun I think.

How do you divide up the airtime between those characters? Because you very cleverly get a balance where you follow all five journeys fairly equally. How hard was that to do?

Yes, at different times we focused on each character during the process of developing the show. We kept going back to the stories and thinking them through in the context of the balance of each serial story that each of them has.

In some ways building the characters is instinctive and you are guided by your gut, especially Tom's instinct. I think we had a very methodical approach to that, in the development process and particularly during the writers' rooms we would put everything up on a board, as you do, and track each character through the show and make sure that we spent enough time with each character, in each episode to really understand where they were moving in terms of their serial story.

In each episode we focus, not in a formulaic or particularly dogmatic way, on an individual character. In each episode each character will have a story, we try to rotate that as much as possible to keep it feeling mixed up and interesting.

How much did bringing Alice and Brittney in help to develop the voices of the female characters?

I think that all of the characters develop when you bring the actors in and that is really what's exciting. Even in the first audition tapes you see, you suddenly see a character and think "ah that's it, that is who that is!" For example Ashley, Brittney's character, was originally written as a much more waspish middle class character. When we met Brittney, she brought a much more particular sassy tone to it.

When you see each character come to life in the hands of the actor, you start to discover things or at least your assumptions are challenged about the way that that character will be played, even for Tom who wrote it. Often that's a really helpful part of the process, often you might say "that's not quite right for the character", but often you make a lot of really exciting discoveries.

Although, broadly, the characteristics of the character need to stay the same because they need to have the same kind of story function at the end of the process as they did at the beginning; often the nuance of the character change.

Ashley was written with a slightly different nuance, she was more privileged, slightly more stuck up character and when Brittney played her she had a more down to earth charm and was much more punchy than we'd imagined her. Suddenly the character came to life. I suppose that is the true of all of the characters. They are vivid in Tom's mind and you can read them on paper and understand who they are, and you have a certain picture in your head. It's only really when you see the actors bring them to life that you can really understand them and shape them finally into who they become.

Alice is outgoing, but her character May is quite the opposite...

Yes I'd say out of all of the characters, she is the most different to her character, but interestingly, when we first started talking to her about it, we made that exact observation that May is bookish and anxious and Alice is quite the opposite.

Actually, Alice said that when she was younger, she had been a lot more like that, so in part her personality as it is had kind of blossomed at university and that was her former life - so we've regressed her in that respect! They all have elements of their personalities in their characters and that is an important part of the process into finding the characters is bringing them to life off the page.

We've talked about the dynamic Greg being of that older generation of traveller, meeting and interacting with this younger group. What were you trying to say with that character?

What that said to me personally was that my life is basically over because I am exactly the same age as Greg! When we first arrived in Kuala Lumpur and I saw some people about the same age as the group, aside from Greg obviously, I was intrigued by their conversation so I sidled over and started speaking to them and they very quickly stopped speaking to me and left. So I got a pretty clear window of what it's like to be Greg.

I think Tom put it really nicely when he said that the truth of it is that if Greg had gone when he was 10 years younger they would have been best friends. He is the same as them, he's just older, and that is what makes him tragic in their eyes. I think it says a lot about being in your early 20s, I remember when I was at university there was a guy we called 'Old Phil' and he must have been 30. When your 19, 22 seems quite ancient.

I think Greg is such a wonderful character because he is one of the more obviously comic characters and regarded as such by the younger characters because he's old. But of course he's the only one of them really that's had an actual proper life because he's started to live it. I think it's really moving when you see the characters start to realise "Oh god this isn't just a joke old person, this is a real guy who is going through a divorce". They become very close friends, which I think is rather moving.

What is the show ultimately trying to say?

I think the show is saying: "you can't take a holiday from yourself" in many ways. It shows that no matter where you are, really your life is about relationships and how you treat other people. That's the way that you learn about yourself.

Even Sean and Dylan are in the middle of China, they could be in a high street in Basingstoke or wherever, they are still two friends who have grown apart who are trying to reconnect. Ash and May are in the early stages of friendship, sniffing each other out trying to work out who they are, clashing up against each other and eventually they become really close.

The show, in some ways, in a really enjoyable way, is quite a simply a show about relationships. I suppose most shows are, but the fun trick it plays is that it sets these conversations, relationships and changes in people's lives against this epic backdrop: the Great Wall of China, the cityscape of Shanghai, the Jungles of Malaysia, but really in those situations it is the story of a guy who has been unfaithful to his girlfriend or is having a crisis with his best friend, or a guy who's having a breakdown because he's in the midst of a messy divorce. The show is, in some ways, about that: no matter where you are it's still you who's there, and you'll still be there worrying about whatever is was you were worrying about before.

There's loads of experiences I've had on the shoot which make you stop and think 'wow we are actually making this show and it's exactly the show we hoped it would be'. Being stood with Tom, Jamie and Jonathan, the director, on the Great Wall of China, having just finished all of the shooting and thinking 'we actually did it, we actually shot on The Great Wall of China.'

There is always a moment on a show, I think, where you stop and see 150 people in Hi-Vis jackets moving all the equipment around and the actors actually doing stuff, and you think 'Holy Christ, we're actually making this, this is actually happening', and for me that is particularly exciting on this show because I've got a terrible memory, but I do remember when Jamie and I were sat in my living room talking and we hit on the idea of doing a show about people travelling where we actually went to the places where it was set, and actually went on a huge travel with the crew and so, when we were shooting on The Great Wall of China, we'd wrapped there and the sun was setting and we'd just finished the last shot before the sun was set and Jonathan, Jamie an Tom and I were up there looking out and thinking 'we actually did this' and watching everyone drift down with all the equipment on their backs and having to take some down myself, was an amazing moment.

My daughter and my wife came out to Malaysia and taking them to set and introducing them to everyone was fun. I remember one day where we were shooting in the Jungle in Malaysia and I was sort of lurking around, didn't have much to do because the Internet wasn't working in the jungle and so I went off to get everyone ice-cream and went to the local shop, bought all the ice-cream in the shop and everyone shared them and moments like that are really special.

What makes this show different?

For me what's really exciting about the show is you don't often see shows of this kind filmed in the locations that we were filming in. In general you'd expect to see an epic about Genghis Khan or Marco Polo or Indian summers... those kind of shows that are epic, often period pieces filmed in these sumptuous, beautiful locations and what I really liked about the idea as it developed was getting the access to those locations and then effectively pissing up against the wall by making a comedy drama about a bunch of idiots travelling round the place.

Obviously the show has far more to it than that, it is a show that is very moving and has a lot of depth to it but fundamentally it is a comedy drama about a group of young people and a slightly older guy, who is my age, and the silly scrapes that they get up to and their lives as they come to understand themselves, but filmed against these quite surprising, epic locations - the Shanghai skyline or the great wall of China, the jungles in Malaysia, the beaches in Thailand, the Full Moon Party, Nepal which is an insane place to visit - or an insane place to film in that's for sure!

So that I suppose is the spirit of the show to me it's crazy, surprising, difficult to access locations where we play out the kind of drama that you could almost film anywhere, in quite a domestic location in fact. But there is something about the mischief of setting it in these kind of locations that really appealed to me.