There were 46 cases of fallen windows in the first 11 months of this year, figures released yesterday show. In the whole of last year, there were 56 cases, and in 2012, there were 71, said the Building and Construction Authority (BCA) and the Housing Board in a joint statement.

Of the 46 cases so far this year, 23 involved casement windows while 19 were sliding windows. The remaining four cases involved other window types, such as louvre windows. There were no injuries reported in any of the cases.

The BCA and HDB said the windows in homes can deteriorate over time due to wear and tear. And without regular maintenance, they may potentially be dislodged or fall off.

BCA's director of the enforcement and structural inspection department, Mr Lim Beng Kwee, said: "Each case is a danger to the community, with potentially fatal consequences. Falling windows are preventable when home owners know the risks, do their duty to check their windows once every six months, and take immediate action to secure and repair them."

The key cause of fallen casement windows is the corrosion of aluminium rivets, which means they are unable to hold the window panels firmly in place.

Since 2004, home owners have been required to replace all aluminium rivets in casement windows with stainless steel ones.

In the case of falling sliding windows, most were due to the lack of proper safety stoppers and angle strips to ensure window panels are kept within the tracks. Such panels may detach when home owners apply additional outward force when opening or closing the windows.

The BCA and HDB urge home owners and occupants to make window safety a priority by following three steps: check, clean, change.

Those with casement windows should check that fasteners are not rusty or loose, clean and oil joints or moving parts, and change all rivets to stainless steel ones by engaging an approved window contractor.

Those with sliding windows should check that safety stoppers and angle strips are in their proper place, clean the tracks and ensure window panels can slide smoothly, and change worn-out safety stoppers and angle strips by engaging an approved window contractor.

The public can visit the BCA and HDB websites for a list of window contractors. Since 2006, 342 people have been fined and 92 people prosecuted over fallen windows.