A man in custody accused of murdering an elderly Upper Hutt woman in an arson attack has been granted bail for six hours to attend his mother's wedding but won't be able to toast her with a glass of champagne.

Upper Hutt storeman Nicholas Andrew Edgarton, 19, is one of three people jointly charged with arson and murdering Joan Elizabeth Betti, 71, on September 3.

Edgarton has been in custody since his arrest in October but in Upper Hutt District Court yesterday, defence lawyer Mike Antunovic made a bail application for Edgarton to attend his mother's wedding on February 18.

Police did not oppose the application.

Judge Chris Tuohy allowed Edgarton to be released from custody for the wedding, subject to a number of conditions, including that he be picked up from prison at 4pm by his uncle, and travel directly to the wedding. He is not to leave the wedding without his uncle and must be returned to prison no later than 10pm. He is not allowed any alcohol or drugs and must not contact a list of people, some of whom had been invited to the wedding but would now not attend.

Edgarton must not drive any vehicle and cannot enter Upper Hutt, other than travelling through it on the way to and from the wedding.

Other than for those six hours, Edgarton was remanded in custody until May 22 for a depositions hearing in Lower Hutt District Court.

His co-accused, Carol Clayton, 57, sickness beneficiary and Richard Steven Pearce, 21, labourer, both of Upper Hutt, remain in custody.

Clayton is also charged with attempting to murder Mrs Betti's daughter and granddaughter, who were in the house at the time of the fire.