Gentle coming-of-age comedy-drama “Days of the Bagnold Summer,” which world premieres at Locarno Festival Wednesday, is the directorial feature debut of British actor Simon Bird, best known as the star of hit comedy series and movie franchise “The Inbetweeners.” Bird spoke to Variety in advance of the screening in Locarno’s Piazza Grande.

The film stars Earl Cave – Nick Cave’s son – as an angry teen, Daniel, spending a frustratingly dull summer in his suburban town with his lonely single mom, Sue, played by Monica Dolan. Rob Brydon, Alice Lowe and Tamsin Greig deliver deliciously witty cameos.

The film was produced by Matthew James Wilkinson, one of the original producers of box-office smash “Yesterday,” who also produced Bird’s directorial debut, the short “Ernestine & Kit,” which premiered at SXSW in 2016.

“Bagnold Summer” is based on the graphic novel by Joff Winterhart, and was adapted for film by Bird’s wife Lisa Owens.

What was it about the graphic novel that persuaded you to adapt it as a film?

It was the tone of it, which is understated, observant, poignant and funny, and those are the qualities that I enjoy in the films that I watch.

It felt like there aren’t that many British films made that are coming-of-age comedy-dramas set in the British suburbs, so there definitely felt like there was a niche there to be filled.

Is there a core issue around which you built the film? Was it the relationship between the mom and her son, and his transformation through the film?

Yeah, I think so. For me the key was as well just making sure that the story was shared between the two of them. It’s a coming-of-age film but not just Daniel’s coming-of-age film, it is as much Sue’s as Daniel’s. And that is what’s brilliant and so original about the book – it is just as empathetic towards this struggling single mum as it is towards the teenage metalhead.

What was the tone you were looking for in the film and the world that you created?

The films that I love to watch, the ones that sit somewhere between comedy and tragedy, are often quite delicate, small, precise films. So I guess that I wanted something like that… that was understated and felt honest and relatable.

In terms of the portrayal of Daniel, I read that you didn’t want him to be too one note: the moody teenager. Can you expand on that?

That came from the casting process. We saw a lot of kids come in and do the grumpy adolescent that we have all seen in TV programs and films before. The book is more complex, and the Danny in the book is more well-rounded than that, and his moodiness is clearly just a phase he is going through – a protective shell he’s put up around himself. It was important to me to find an actor who, as well as being able to do that side of things, was able to portray a degree of vulnerability, and someone who had a sense of humor and could nail the jokes as well. And fortunately we got Earl who was great at all those different facets of Daniel’s character.

Was it also important that it was believable in terms of the story and the setting? For example, his relationship with his father.

Yeah, totally. The key is that you sympathize with him, and you understand where his moods are coming from.

What were the films that provided the inspiration for the tone of your film?

When I started looking for references of films that existed in the same world I really couldn’t find many British ones… those coming-of-age comedy dramas don’t seem to be something that Britain has a history of making. Richard Ayoade’s “Submarine” is the exception to that. Most of the films we were looking at as direct references for this were American: so films like “Rushmore,” “Welcome to the Dollhouse” and “Dazed and Confused,” those summery, suburban coming-of-age films; and “We Are the Best!,” a Swedish film about some punk rock loving teenagers. Most of the films we looked at were bright, music heavy, American, indie comedy-dramas. It was a deliberate decision to do something that isn’t done much in Britain, which is make something that celebrates the suburbs rather than reveling in the misery of them.

Why did you want to direct a feature film?

In my parallel careers I’ve been involved in lots of other different aspects of filmmaking and while acting is really fun it is not necessarily the most creatively satisfying thing you can do. And I found myself feeling quite jealous on set of the writers and the directors – the people who have more of a say over how the film turns out… and basically I’m a bit of a control freak – I like the idea of seeing an idea through from the very start to the very end. And it was every bit as rewarding as I had hoped. You get a taste for it. It is definitely something I want to do more of.

Have you got other projects you are working on?

Sort of. Nothing I can really speak about. Some things are in their very early days.

Would you take the characters [in “Bagnold Summer”] on into another film or a TV series?

I don’t think so. The point of that story is how small and bathetic it is. It’s nice that you see a slice of their life and any progress they’ve made as characters is so minimal that you can read into that what you like and imagine how their lives are going to turn out. So I think I’ll probably move on and do something different.

Did you draw on your own memories as a teenager. Were you a difficult teenager?

I probably didn’t go through a phase quite as tricky as Daniel in the film, but I definitely had my moments.