Sia Furler opens the door of her hotel suite, hugs me, then hops back into bed. For the next 90 minutes, she will get up only to sign for a beanburger and chips – “I think I may be vegetarian at the moment,” she muses – although she won’t stop talking long enough to eat much of either. The 33-year-old Australian singer, known simply as Sia, puts her verbal diarrhoea down to delirium: she was downing white russians after a gig in Glasgow the previous evening, then flew to London, and she still hasn’t slept.

Best known for her work with Zero 7 – she is the only guest vocalist to have appeared on all three of their albums – Sia is set to break through as a solo artist with her new album, Some People Have Real Problems, released this week. A mix of glossily produced midtempo tracks and big ballads, mostly about break-ups, it won’t be a cool indie kid’s cup of tea, but intriguing arrangements, lyrics that rub on raw wounds, the appearance of Beck and glorious vocals that flit from spine-chillingly creepy to Mariah Carey-esque crooner could make it 2008’s classiest coffee-table pop purchase.

Reconciling the harsh Aussie accent, lairy language and throaty cackle of the blonde-bobbed ladette with such striking vocals has always been hard to do. At early Zero 7 shows, the audience would audibly gasp when Sia spoke between songs. “The first time I got up on stage in London, people laughed,” she says. “I was this loud, overweight Australian everyone was expecting to be shit. It was a jam, and the band were playing a cover of a song I didn’t know. I made up my own lyrics and a melody on the spot. The crowd went crazy. It was like a scene from one of those naff 1980s pop movies – the fat kid turns out to be a star. By the end, a guy was frantically running in front of the stage, shouting: ‘You’re with me.’ He ended up being my first manager, and got me on Top of the Pops.”

In 2000, Sia signed to Sony and recorded her debut album, Healing Is Difficult. After a couple of club hits, her Prokofiev-sampling single Taken for Granted reached the Top 10. Then, disaster. “The album flopped and I realised my manager had signed me to a terrible deal,” she recalls. “When I did Top of the Pops, he couldn’t afford to pay my string section. After he kept asking me for 50p to use the phone, I finally sacked him.” What Sia calls her “first resuscitation” came the following year, when Simple Things became a sleeper smash. “The one great thing that manager did was introduce me to Zero 7,” she says. “I wrote two tracks with them, which took 45 minutes to record. I had totally forgotten all about it, when suddenly the album took off. By then, I was planning to become a dog rescuer.”

Picked up by Robbie Williams’s management, Sia signed another solo deal, but even she concedes the resulting album, 2004’s Colour the Small One, was desperately depressing. The reason was the death, seven years earlier, of her boyfriend Dan, who was knocked down crossing Kensington High Street on his 21st birthday.

“Dan was my first love back in Adelaide,” Sia says. “We had split up, then got back together, and decided to travel the world together. I was en route to London to meet him, but stopped off to spend a week at a retreat in Thailand. After his funeral, I came to London to stay with his friends. We were all devastated, so we got shit-faced on drugs and Special Brew. Unfortunately, that bender lasted six years for me.” When Colour the Small One flopped, she took an overdose. “I tried to commit sleep, which is so embarrassing,” she laughs. “I didn’t know you couldn’t kill yourself on Valium and vodka. I just slept for 2½ days, then someone took me to the hospital.”

The therapy sessions she attended afterwards helped her realise how strange her life had been. Her father, Phil, a blues guitarist, was a schizophrenic with an abusive alter ego he called Stan; her mother played in a lesbian version of Men at Work; and her half-brother had been arrested for trying to fake his own murder. Music had always been her escape – with an Aussie acid-jazz outfit called Crisp, then in Tokyo, where she earned a crust as a singing pole-dancer.

Since she relocated to LA two years ago, Sia’s luck has finally turned. A new song, Buttons, for which she directed the acclaimed video, became the second most popular posting on YouTube. Then the producers of Six Feet Under chose her broody Breathe Me to soundtrack the final five minutes of the last episode. Almost 7m have since flocked to Sia’s MySpace site, and Some People Have Real Problems is expected to be a big hit. “The best part is that I’m happy,” she says. “I’m like a walking advert for failed suicide bids. Don’t do it, because you never know what’s round the corner.”

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