A builder who torched a South Melbourne pub part-owned by Collingwood AFL star Dane Swan says he only intended to start a small fire because he needed more time to finish renovations.

The Albion Hotel was destroyed on October 5 last year just before it was about to re-open after a $1.38 million refurbishment.

Andrew McMahon, 47, of Berwick, pleaded guilty to one count of arson in the Melbourne Magistrates’ Court on Wednesday.

He told police he was “in a panic” when he started the fire.

“I just needed a couple of weeks for the build,” McMahon told police.

“I am truly sorry.”

He said he had only intended to start a “small fire” with a “little bit of damage”.

Pub owners Swan, former Melbourne Storm NRL players Robbie Kearns and Danny Williams and former Western Bulldogs player Luke Darcy’s brother, Matt, were expecting an official launch on October 23, but the building was destroyed by the blaze.

Police say there was an additional motive of financial pressure due to a cost blow-out.

“An example of this is the plumbing budget for the build which was quoted by the accused on the cost report as being $40,000,” police said.

“The actual amount that would have had to have been paid for the plumbing if the build was completed would have been approximately $100,000.”

Twleve days before the fire, Mr McMahon increased the insurance on the renovation from $1.2 million to $1.8 million, court documents show.

McMahon will face a Victorian County Court plea hearing on February 21 next year.