There were 28 cases of fallen windows in the first five months of this year, almost double that in the same period last year.
No injuries resulted from these cases.
Last year, there were 16 such cases in the first five months. This year's figure is higher than the last five years' average of 24 cases.
Home owners should check their windows every six months and make the necessary replacements, the Building and Construction Authority (BCA) and the Housing Board said in a joint statement yesterday.
Most of the fallen windows were casement types, found to have corroded aluminium rivets that were unable to hold the window panels in place, the agencies said.
As for those that were sliding windows, these fell as they did not have safety stoppers and angle strips to secure the window panels, and the windows could not slide smoothly along the tracks.
Home owners are required to engage an approved window contractor to retrofit the aluminium rivets of casement windows with stainless steel rivets or screws.
Number of cases of fallen windows in the first five months of this year, compared with 16 in the same period last year
If a window falls due to lack of maintenance, home owners can be fined up to $10,000 and/or jailed for up to one year.
Those who fail to replace aluminium rivets in casement windows with stainless steel rivets can be fined up to $5,000 and/or jailed up to six months. Since 2006, 307 people have been fined.
Said Mr Lim Beng Kwee, director of BCA special functions group: "Falling windows can cause serious injuries to others in the neighbourhood.
"We should all do our part to ensure that public safety is not compromised."
He added that BCA will raise public awareness on how to conduct proper window maintenance.