Survivors producer Hugh Warren sets the scene for the return of the post-apocalyptic show... Words: Paul Simpson

Were you pleased with the reaction to the first series?

We were delighted to be recommissioned on the back of our rating figures. I think it's a series that attracted a very loyal audience. As always, we lost some viewers from the first episode, but people were very loyal and then it grew again towards the end, apart from the very last one, which was transmitted the day before Christmas Eve when people are shopping or travelling.

Anecdotally, people don't watch it casually – they either don't watch it, or they absolutely do watch it.

Did the BBC request many changes?

Not particularly. They were very pleased with the demographic of the audience, primarily because it attracted a lot of younger men, who are hard to get in popular television.

The feedback from their audience research was to stick with our core Family. I think people were frustrated when we went off to ancillary characters and then left them. People wanted to know what happened to them subsequently. That's partly the reason we're more a serial this year.

Why are you shooting in Birmingham this year, rather than Manchester?

There's a very practical reason. The nature of Survivors is that we need an abandoned world with no people. That's incredibly limiting when you're shooting in a city. If we want to film on a street, we have to close the whole street and that is not easy.

Although Manchester worked very well for us last year, and we got great production values from it, we felt we'd pretty much exhausted it even during the shooting of that first series. We had to keep going back to locations because they were the only places we could close down, other than very early on a Sunday morning.

We went all over the country. Birmingham worked for us because it has the scale, so it feels like Manchester – in story terms, we're still in Manchester – and it also had a variety of locations that worked for us. The council were very co-operative, and were very keen to have us there. We have managed to get a scale of closure in the city that we didn't achieve last year.

Were there any misfires last year you've had a chance to correct this time around?

Possibly. The nature of the story of the week being locked into a series structure was probably too restrictive. It's been good this year to be able to carry story arcs across several episodes. On the whole, that's fallen into two-parters in a way – the first two are in the city; the second two have a direct continuity within the story, the final two also.

The other change is that the confidence in the show has allowed us to have much darker storylines. If you were doing the "social realism" version of Survivors, it would be very grim indeed. The BBC were frightened that that was not an appealing, entertaining, primetime BBC1 scenario. Last year, we spent a lot of time talking about the "Grim-ometer". Anything we felt was going to be too grim we steered away from. We were locked into an entertaining, action-adventure genre. This year we have not had that fear, because we are very confident in the world and our characters, so we have gone much darker.

We've also given Sarah a much bigger storyline this year – she has a romance, and a big story in episode five, which is based around her. Robyn has really responded to that as an actor, and she gives a fantastic performance.

Drama across the BBC has had reduced budgets this year. Has that affected production values?

Honestly, I feel that production values are higher than last year, and we've achieved that by being very focused on where the money goes. We had to move from 35mm to HD as a means of saving money. That was a pure financial decision. Last year we were nervous because of the nature of the Survivors world – there's no power, so there's no excuse for practical lighting.

We're in low light levels and exteriors, and my own experience of HD was that it was not great for that format. Having said that, the format has come on enormously, and we were confident we could go to HD without compromising that in any way. We've got very good DoPs, everyone is becoming more familiar with the medium, and the cameras are getting better.

Have you moved beyond Terry Nation's book?

It's our source, but I think by series two, we've got our own worlds and our own characters, so we've gone off from the book. Obviously at the beginning there's a lot with the lab, and the back-story of the virus, that is not in the book.

What's been the biggest challenge producing Survivors?

Keeping the production values within the budget. The storylines have been challenging, initially with a lot of CG – episode one has a challenging storyline with a collapsing building, trapped bodies. The final block is set in a glorious bucolic environment – but when you're based in the middle of a city, you've got to travel!

CG as a tool is developing so fast, and it's a question as a producer of gaining confidence, and understanding that you can do things with CG that isn't going to cost a fortune. There's a real sea change going on within the industry generally.

We have a scene with Al and Sarah where we needed a beautiful environment – it was easier to shoot it against greenscreen and paint that environment in, than move the whole unit to find a location. There are lots of things you can solve with CG. It's a really useful tool.

Are there any stories you've held back because you don't think the show is ready quite yet?

Inevitably, there are. We talk about all sorts of storylines and scenarios, particularly around our central Family, and there were various deaths of various characters that have been talked about. There were some things we did shy away from, that we felt were inappropriate and would take our characters into too dark an area.

Survivors is currently showing on BBC One on Tuesday nights.