TOO fat, too thin, too plain, too pretty...

It's no wonder many actors dread the feedback doled out to them at auditions.

Andrew Buchan, star of ITV's runaway hit Broadchurch and weighty BBC drama The Honourable Woman, actually enjoys reading for roles though, something he freely admits makes him "a bit weird".

"I like to audition," says the 35-year-old, smiling. "I like to earn my place. I'm like, 'You don't know me, I might ruin it'."

Having played both a grieving father in Broadchurch and the son of a murdered arms dealer in The Honourable Woman over the last 18 months, Buchan's gaining a reputation as the go-to guy for bleak roles.

"I often audition at a studio in central London. I did the scene in Broadchurch where I identify my son on a mortuary board there," recalls the actor, who found his small screen breakthrough in political drama Party Animals, before going on to take roles in Cranford and Garrow's Law.

"After that, I auditioned for something where I was in a car and a bomb was about to go off, and I could do nothing about it.

" Then I auditioned for The Great Fire, where there are so many scenes that are high stakes and emotional."

The Great Fire is a lavish production, based on the true story of the fire which started in Thomas Farriner's Pudding Lane bakery in 1666 and roared through London, destroying more than 13,000 houses in its wake.

Buchan, who lives in Buckinghamshire with his wife Amy Nuttall, who played maid Ethel in Downton Abbey, is taking on one of the biggest roles in the series, as humble baker Farriner.

"Most of the ordinary working people lost everything they had in the fire, and you realise just how much they suffered," says the actor, who knew "next to nothing" about the historical event before he landed the part.

With smoke filling the set, real fires raging, "manky teeth" and "muck and soot" inserted into his ears ("Everyone forgets the ears!"), The Great Fire wasn't a glamorous job, but it's one that will linger in Buchan's memory for a long time.

"It's point-blank terrifying," he says. "We did a scene in a prison and filmed it in these dungeons. They pumped it full of smoke.

"You can't see your right hand, you've got sweat pouring in your eyes and constant coughing... it's possibly the hardest three days filming I've done."

Much as Buchan, who studied Modern Languages at Durham University before learning his craft at the Royal Academy For Dramatic Art, loves getting stuck into these big meaty roles, he now craves something a little lighter.

"Comedy is all I used to do pre drama school," he says. "But you need to be careful what you wish for.

"I used to like making people laugh at drama school, and the teachers would be like, 'Oh, you're the class idiot are you?'

"And I'd be like, 'No, I'd like to do a Paddy Considine in Dead Man's Shoes', and then you go down that route - and now having done a good nine years of darkness, I'm ready for comedy."

What he's not ready for though, is a move across the pond simply for the sake of it: "You have to sign up for seven years for an American pilot, but you're only given 30 pages of A4 to read," says the actor, who has an agent in Los Angeles.

"It seems stupid really, unless it's The Wire, and only 0.01% of the scripts are that. You could end up in something hellish for seven years."

With Broadchurch under his belt - which peaked with 9.3 million viewers and inspired a US remake - plus The Honourable Woman picking up a Best International Drama award at the 16th Festival De La Fiction TV earlier this year, Buchan has found an upswing in the number of black tie award dos he's been asked to lately, which means there's a lot of "dressing up like a penguin", he notes.

He is pleased with the success of Broadchurch, but still slightly taken aback by the reaction.

"It just took off, and I don't think any of us expected that," says Buchan, who's currently filming the second series.

One of his biggest fans though is very close to home; his "brilliantly supportive" Scottish father, who encouraged Buchan to go to university before drama school, "just as a back-up".

"After graduating I said, 'I still want to audition for drama schools', and from that point on he's been very, very supportive," says the actor, who was born in Stockport and raised in Bolton.

"He watches everything I've been in. He's now 70, so he's coffee shop-hopping of a day and telling random stories about me.

"Sometimes when I'm there as well he'll say, 'Do you know what he does? That's my son'. He's a very proud dad."

Although Buchan's mum died 14 years ago and didn't live to see her son's success, he's pleased she did see him on stage.

"My mum saw me play Hamlet," he says. "She was very pleased about that, and had a tear in her eye afterwards."

l The Great Fire, ITV, Thursday, 9pm