Is strata liable for mould found between double glazed panes?

Mould between double glazing, who is responsible?

If mould or contamination is present between the two panes of a double-glazed unit, this is generally an indication that the sealed glass unit has failed.

Double glazing, commonly referred to as an IGU (Insulated Glass Unit), consists of two panes of glass separated by a sealed cavity. This cavity is inaccessible and not designed to be opened for cleaning.

If moisture has entered this cavity and mould or contamination has developed between the panes, cleaning the glass is generally not an option. In most cases, you'll need to replace the affected insulated glass unit.

A window contractor's first step would be to inspect the window and confirm the failure of the sealed glass unit, along with checking whether there are any other contributing issues with the window system.

The next question is who is responsible for the replacement.

In a strata property, windows forming part of the common property are commonly the responsibility of the owners corporation. However, I would recommend checking the registered strata plan and the scheme's by-laws before determining responsibility.

This becomes particularly important with double glazing because it may not necessarily be original to the building. If a previous lot owner upgraded the windows or glass from single glazing to double glazing, a by-law or approval for those works may place responsibility for ongoing maintenance and repairs with the lot owner.

The fact that the current owner believes the mould was present when they purchased the property two years ago doesn't change the technical issue with the window. If contamination is genuinely trapped between the panes, the sealed glazing unit has failed at some point.

Our recommendation would be first to confirm the failure and establish whether the double glazing is original or a subsequent alteration. The strata manager can then review the strata plan and relevant by-laws to determine whether the owners corporation or the lot owner is responsible for the replacement.