The number of windows falling from high-rise homes is the lowest in five years, says the Building and Construction Authority on Thursday.

There were 40 cases in the first eleven months of this year, compared to 67 in the same time period last year.

About 60 per cent of this year's cases involved casement windows. Most of these occurred because the aluminium rivets securing the window panels to the frames had corroded. No one was injured by fallen windows this year.

Home owners are required to change their aluminium window rivets to stainless steel ones, or face a fine of up to $5,000 or up to six months of jail.

If a window falls due to lack of maintenance, they could be fined up to $10,000 or jailed up to a year.