Skip to Content

Frequently asked questions

Windows Maintenance

Aluminium windows do not have a specific life span. However, owners are urged to pay special attention to the conditions of individual parts of the window (e.g. bar hinges, screws and rivets, etc) and arrange for repair or replacement if needed. Through proper use, regular inspection and timely maintenance, the safety of aluminium windows can be assured.

According to the findings from the previous incidents of falling window, one of the major reasons is the failure of rivets/screws of the hinge due to corrosion or the wear and tear over time. Besides, lack of proper maintenance and improper use of aluminium windows are also the contributing factors for windows falling.

It is owner's responsibility to check and maintain their windows regularly to ensure safety. The owners may be held liable for personal injuries or property losses resulting from falling windows from their premises.

Under Section 4B of the Summary Offences Ordinance, if anything is dropped or allowed to fall from any building to cause danger or injury of any person in or near a public place, the person who drops that thing or allows it to fall commits an offence and is liable to a fine of $10,000 and imprisonment for 6 months.

If the falling window causes injuries or loss of life, the victim or their family members may also claim compensation against the owner of the flat involved through civil proceedings.

A Qualified Person (QP) is an Authorized Person (AP), Registered Structural Engineer (RSE), Registered Inspector (RI), Registered General Building Contractor (RGBC) or Registered Minor Works Contractor (RMWC) registered for class, type and item of minor works in respect of windows. Please refer to BD's website ( and the Mobile Application "Quick Guide for MBIS/MWIS" for details of the various registers of AP, RSE, RI, RGBC and RMWC and the reference list of QPs. The public can also download the Mobile Application "WIN SAFE" to search for and appoint QPs registered in the WIN SAFE. The Buildings Department issues a QP Card for QP. For identification purpose, you may ask the QP to produce his/her QP card or the certification of registration under the relevant register; as well as to ensure the QP carries out the prescribed window inspection personally.

The standard of prescribed repair for windows shall not be inferior to that of the original design. However, you may also choose to upgrade the construction standard of the windows to meet the current requirements during the course of repair. All defective window components affecting window safety must be repaired or replaced. As for those window components not affecting safety e.g. weather sealant, weather gasket/strip, etc., they are not within the scope of prescribed inspection and repair under MWIS. The BD has published relevant standards and guidelines in relation of the MWIS, including the Code of Practice for the MBIS and the MWIS, General Guidelines on MBIS and MWIS, and Important Notes about Window Safety, to help facilitate building owners in understanding the requirements under MWIS and properly arranging inspection and necessary repair. Please refer to BD’s website for the details of various publications.

The cost of inspection and repair for windows varies with such factors as the building size, the number and size of windows in the building, their conditions of maintenance and repair, and the prevailing market conditions of the trade. At present, there are already a sufficient number of Qualified Persons (QPs) and registered contractors to provide a level playing field in the market. Some minor works contractor associations have compiled and published in their respective websites lists of their members willing to provide services as QPs and cost reference. Hyperlinks to the websites have been made available at BD webpage to facilitate easy access by the public. Some market information for window inspection and repair works under the MWIS obtained from the quotations/advertising pamphlets provided by the QPs/ registered contractors are also published at BD webpage and the Mobile Application "WIN SAFE" for general reference. Owners may obtain quotations with detailed cost breakdown from different QPs and registered contractors for cost reference and comparison.

As a consumer, you may make reference to the pamphlet published by the BD about owner’s right. If you are not satisfied with the services provided by the QP appointed, you may cease the appointment and re-appoint another QP to carry out the prescribed inspection / supervision and an independent registered contractor to carry out the prescribed repair found necessary. In respect of suspected irregularities, misconduct or negligence of the QP, you may report to the BD at telephone no. 2626 1616 (handled by 1823).

Under the MWIS, obstruction to windows due to decoration or furniture placed inside the building or individual premises cannot be considered as an excuse for exemption from the prescribed inspection. On the contrary, the condition of these windows may have been overlooked by the owners or occupants, thus posing a higher risk of danger to the public. Therefore, the owners have to arrange inspection to these windows to ensure public safety.

Rivets or screws found loosened/missing/with greyish white powder or rusting must be replaced and the renewed components shall be of such material and size not inferior to that of the original design. When replacing a hinge, at least 3 numbers of rivets or screws shall be used. When replacing a hinge with a stainless steel hinge, or replacing the rivets or screws of an existing stainless steel hinge, stainless steel rivets or screws must be used.