Alec Newman is talking homecomings, a gloriously lyrical tale of lost connections, bonds re-forged and unearthing buried roots.

It's a story which deserves a roaring fire and a nursed whisky or two. Instead, however, we are in the green room of BBC's Waterloo Road set, lounging on an ageing sofa, the intermittent hiss of a kettle in the background. The smell of fresh paint lingers in the air, slightly incongruous against the scuffed red and white linoleum underfoot. Out of the window, behind Newman's head, you can see over the chimney pots of Greenock to the Firth of Clyde beyond.

The actor, who was born in Glasgow but moved to Berkshire aged four, is speaking about a recent road trip with his father. He smiles softly, eyes twinkling. "I'm staying just up the road from where my father lived in Finnieston when he was a baby," he says. "He came to visit me and we ended up doing this impromptu tour in the car. He pointed everything out: 'See that Tesco there? That used to be a picture house. That's the Italian cafe where my brother would take me when I'd been good. That's the church where I went to the Boys Brigade.' He went into this weird trance as we drove round.

"It was lovely to see things through his eyes and hear his memories, because Glasgow has always been a sort of ghostly place for me. I have this strange connection having been born here and with my family being here. It is in me – it is part of where I'm from."

It's a little more than three months since Newman arrived in Scotland to shoot the new series of Waterloo Road. The BBC drama was previously filmed in Yorkshire but relocated to Greenock in April, bringing a £25 million boost to Scotland's television industry.

The move is part of BBC efforts to increase network programming from Scotland. The show, made by Shed Productions, is now in its eighth series and regularly attracts more than six million viewers.

In line with the show's new home in the former Greenock Academy, its storyline will see many of the regular cast leave behind the gritty state comprehensive in Greater Manchester to establish a new independent school in Scotland.

Newman, who is 37, plays headteacher Michael Byrne, a tough and fiery character who made his debut in the series last year. The move sees Michael returning to Scotland after 20 years away – which for Newman has become an uncanny case of life imitating art. "It's been fun for me," he says. "It is a homecoming for Michael and there is that parallel for me too. Of course there's that old thing, because I grew up and live in England, that I'm a sassenach, not the real McCoy. Bring it on. I know where I'm from."

Despite many years spent living in London as well as Los Angeles, an unmistakable Scottish lilt to his voice endures – far from the estuary English twang you might expect. That said, not everyone is quite convinced. "One of the first things a [taxi] driver said to me when I arrived was: 'By the end you'll have a real Scottish accent,'" he says, laughing. "That's a welcome, I think."

"Although I didn't grow up here I still feel a strong connection to Glasgow," he continues. "I was born in the old Stobhill Hospital maternity unit. My mum and dad grew up in Scotstoun, my father lived on Dumbarton Road, my mother in Whiteinch. My Auntie Blanche lives in Erskine, my Uncle Jim in Cambuslang."

There's a faraway look in his eyes as he reels it all off, as if grasping for those ebbing early memories. Newman's family moved to England when his father Sandy's career as frontman of 1970s band Marmalade took off. "He got sick of driving up and down the length and breadth of the country for work – although there was other reasons I'm sure," he says.

As a result, the actor's own background became less Glasgow mean streets than leafy suburban Home Counties. "I grew up in Berkshire – the Royal County of Berkshire no less – so for me to show up in Scotland and try to pretend I was a street urchin made good is not right," he says, chuckling.

There is a magnetic charisma to Newman, all chiselled cheekbones and piercing green eyes. Earlier in the day when I arrive on set I find him singing a tuneful melody in the canteen as he gets his lunch. Later I spot him sitting in the barber's chair in hair and make-up getting a quick trim, the women in the room eyeing him surreptitiously as he tells some raucous story that gets everyone laughing.

While his younger brother John James, 33, plumped to follow in their father's footsteps with a music career (he was a contestant on BBC talent show The Voice UK earlier this year), Newman caught the acting bug at an early age. "I didn't get into the Cub Scouts because the waiting list was too long," he says. "My mum responded to a leaflet that came through the door for the Teatro Theatre School. It was an hour and a half every Friday night and cost £1. They did a bit of acting, singing and dancing. I hated the singing, hated the dancing but loved the acting."

He was, by his own admission, "a real show-off" at school, yet painfully shy around members of the opposite sex. "I was absolutely hopeless with girls," he admits. "I would get so nervous and turn into this idiot who wasn't able to say anything – or if I did manage to speak it was complete garbage."

Sport was his other big love. As a youngster he was as likely to be found kicking a ball around a park as treading the boards. Newman flirted with pursuing his dream of becoming a professional footballer before a knee injury at 17 thwarted that plan.

"That was the end of playing football seriously," he says. "I smashed my knee up. It was bad. I do have a slight gait, but I'm clinging to something Clint Eastwood or Mel Gibson said, which is that all actors need to have a good or distinctive walk."

Newman joined the National Youth Theatre and studied at the London Academy Of Music And Dramatic Art, making his TV debut with the "obligatory appearance in Taggart" soon afterwards. "I played one of a pyjama-clad religious cult," he recalls. "I was the misguided eldest son who turned out to be the killer."

Newman tentatively dipped a toe in the waters of rediscovering Glasgow while filming the Sherlock Holmes BBC drama series Murder Rooms in 1999. "I stayed in what was then the Bath Street Hotel. I came out the front door into supposedly what was my hometown but I had no idea where I was," he says.

This time around he has leapt in with both feet, not least embracing the big-hearted Glaswegian charm. "I got on the bus one day and realised I had no change," he says. "A fellow passenger paid the fare for me. Then I found I actually had the money. As I got off I gave her it back and she tried not to take it. She was waving me away. Glasgow is that kind of place. The people here are unmistakable."

While reticent to be seen as jumping on any bandwagons ("There is a whole generation of Scottish actors who attached themselves to the fact Trainspotting was popular culture, but that's not what I am") Newman has racked up a far from shabby CV with roles in BBC dramas Reichenbach Falls and Silent Witness, Stephen Fry's film Bright Young Things and US television shows Children Of Dune, Angel and Star Trek: Enterprise.

Prior to joining Waterloo Road he played Edmund in the Donmar Warehouse production of King Lear, which toured the UK followed by a run at the Brooklyn Academy Of Music in New York.

It is as suave headmaster Michael Byrne, though, that Newman has found his groove. While parachuted quickly into the role in May last year, he was able to do some belated research prior to the current series.

"I was in the pub near where my parents live when this guy wandered over and said: 'I'm sorry to bother you, but my daughter thinks she watches you on television, is that right?' I said: 'Er, yeah, maybe -'" Newman laughs. "I noticed immediately, though, he was Scottish and asked what he did. Funnily enough he was a head teacher and ran an independent school so I asked if there was any chance of going along to see how he runs things. I was impressed with him and secretly wanted to be around him in his environment."

The man in question – Gregg Davies, headmaster of Shiplake College in Henley-on-Thames, Oxfordshire – duly obliged by allowing Newman and fellow Waterloo Road cast member Daniela Denby-Ashe to spend time observing his daily routine, from toting up the accounts to patrolling the corridors.

"That was invaluable," says Newman. "Simply watching this man at work as he walked about the school. He would be talking to me one minute and then out of the corner of his eye would see someone with a shirt untucked or a tie not done properly at the neck. He'd say: 'Good morning Mr – whatever the kid's name was – you are going to put that tie up to the collar.' I liked all that."

Did Newman then channel that into his own acting? "I wouldn't say directly, but certainly early on in shooting it was all very fresh. There were a couple of scenes where I did think: 'Now, what would Gregg do here?'"

Perhaps the biggest challenge for Newman has been adapting to the unrelenting pace of filming a BBC network drama series. "It's a brutal schedule," he admits. "How many hours am I averaging? The full malarkey. I arrive in work for 7am and work through to 7pm each night.

"It's a different kind of acting than what I had done prior. It's a whole new set of skills from working on a mini series or a film. It's certainly different from a play where you have the luxury of four or five weeks' rehearsal. This show is recorded at a rate of knots. You need to have your wits about you otherwise you do miss little moments in terms of attention to detail."

A frown spreads across his forehead when I ask if that makes him a perfectionist. "I think without that it becomes a bit meaningless," he muses. "It certainly becomes monotonous but it would become meaningless for me too. If I ever settled into a rhythm where I was just knocking it out, it would be time to let someone else have a stab at it."

When not on set Newman can variously be found playing football ("I'm not really supposed to," he says sheepishly), perched precariously on a cliff face ("I have been out rock climbing to the ridge above Glen Coe and up The Cobbler through the eye of the needle – don't tell the insurers for the show") and indulging his passion for books and cinema ("I didn't go to university so I have an academic envy of those who did").

The actor recently started dating Waterloo Road production co-ordinator Heather Stewart. When we meet, the couple are still in the fledgling stages of their relationship and Newman is caught off guard when I probe his love life.

"No, I don't," he says, when asked whether he has a partner. "Currently unengaged." He looks to his BBC publicist, sitting quietly in the corner. "Isn't that right, Julie?" But he's biting back a smile as he says it, which is perhaps the giveaway.

A few weeks later Newman is slightly more forthcoming. "There is someone special in Glasgow to spend my time off the set with now, so London can wait until we have finished filming," he says. "I might yet end up living in Scotland half the time. Who knows?"

He's back on steadier ground talking about his life philosophy. "My mum always says: 'What's for you, won't go by you,' and I truly believe that. In this industry you get big highs and pretty crushing lows and disappointment. Remembering that always helps. I did a pilot in America called Dark Shadows [in 2004] which was going to be the big thing and seemed life changing but the series never got picked up.

"If it had I would probably still be in America perhaps living a very different life, but it wasn't meant to be. Right now, I'm exactly where I need to be, living a stone's throw from where my mum and dad grew up. It all makes sense.

"If this rediscovery of things I have a connection with, of exploring these places for myself, even if that's the only reason I'm up here doing this, my time on Waterloo Road, that would be enough. It has been and will continue to be a personal journey."

There's a pause as he catches himself. "Not being grand about it," he adds hastily. And in that moment the dormant Glaswegian DNA in Newman shines through. n

Waterloo Road, BBC One, Thursdays, 8pm.