Burma's detained opposition leader Aung San Suu Kyi plans to renovate her crumbling lakeside home to keep out trespassers, her lawyer says.

The Nobel peace laureate had her house arrest extended by 18 months earlier this month for violating her detention rules after a bizarre incident in which an American man swam uninvited to her Yangon residence in May.

Nyan Win, one of her lawyers and the spokesman for her National League for Democracy (NLD) party, said Ms Suu Kyi had been in contact with an architect about making renovations.

"She worries for the security of her house and that's why she wants to repair it," he said.

"It is to prevent another trespassing."

Nyan Win said the democracy icon would pay for the renovations herself.

He said she was concerned about security despite the house being more heavily guarded by authorities now than it was before John Yettaw made the trip across Inya Lake using a pair of homemade flippers.

Yettaw was sentenced to seven years hard labour for the stunt but was freed after a visit by US senator Jim Webb earlier this month.

Ms Suu Kyi's own conviction over the incident, which sparked international outrage, means she will not be free for elections promised by Burma's junta in 2010.

She has spent much of the past two decades under house arrest at the family mansion since the junta refused to recognise the NLD's landslide victory in 1990.

After a stint in the notorious Insein prison for her trial, she returned to the house with her two aides, where they live an isolated existence with no Internet or telephone access and almost no visitors except doctors and lawyers.

Her lawyers are expected to file an appeal against her conviction early next week.

- AFP