The 37-year-old revealed several months ago that the group have been talking about a follow-up to 2008's Third, and confirmed today that they will start work on the record soon.
He told BBC 6 Music: "We're going to start writing and if all goes well it could be [out] in a years' time. That would be the most perfect thing to do."
Barrow went on to say that although the band are not currently tied to a contract, they have already spoken to several record companies about releasing new material.
However, he laughed off the idea of Portishead starting their own label, joking: "It would be a complete nightmare. It would end in a nervous breakdown!"