Minor Works Control System Hong Kong: Class I, II and III

The Minor Works Control System (MWCS) is the Buildings Department (BD) system for small-scale building works that the Buildings Ordinance designates as minor works. BD describes it as a lawful, simple, safe and convenient way for owners to carry out works such as installing supporting frames for air conditioners, drying racks and canopies over windows, repairing structural members or external walls, and removing unauthorised structures. It was fully implemented on 31 December 2010. The one thing to get right: the people you hire must be on the right Buildings Department register for the class, type and item of work.

Classes, types and items

BD sorts minor works into three classes according to their scale, complexity and risk to safety, in descending order:

• Class I: mainly the relatively more complicated minor works.
• Class II: works of comparatively lower complexity and risk to safety.
• Class III: mainly common household minor works.

Within each class, works are grouped into types that match how the industry specialises: Type A alteration and addition works, Type B repair works, Type C works relating to signboards, Type D drainage works, Type E works relating to structures for amenities, Type F finishes works and Type G demolition works. Each specific job is a numbered item. Look up the item on BD’s minor works pages before you hire anyone, because the item decides the class and who can do it.

Who you must appoint

RGBC means registered general building contractor, RSC registered specialist contractor and RMWC registered minor works contractor. For Class I, the professionals design and supervise the works and the contractor carries them out. For Class II and III, the contractor prepares and submits the plans and documents, and supervises and carries out the works. A registered minor works contractor may only carry out the class, type and item of minor works it is registered for. Our guide to registered contractors explains the contractor registers.

Submissions and time limits

Minor works use a notification and a completion certificate, not the full plan approval and consent route described in our guide to submitting building plans. BD’s procedures page sets out the timing:

The forms are on BD’s minor works forms page.

Step by step

1. Identify the item. Find the BD item that matches your job and note its class and type.
2. Appoint the right people. Use the table above. Check each name on the Buildings Department registers, including the minor works class, type and item for an RMWC.
3. Notify BD. For Class I and II, the submission goes in at least 7 days before work starts.
4. Carry out the works. Under the supervision the class requires.
5. Certify completion. For every class, the completion submission is due within 14 days after the works are completed.
6. Keep the record. BD’s BRAVO building records system holds submitted plans and photos of minor works, so a future buyer or BD can see what was done.

Older air-conditioner frames, drying racks and canopies

Some minor household installations were put up without BD approval before the system began. BD runs a validation scheme so that installations such as air-conditioner supporting frames, drying racks and small canopies can be kept after validation. See BD’s validation scheme workflow for the current steps. BD also designated a separate group of “designated exempted works”, with lower complexity and risk than minor works.

Common mistakes

• Hiring an unregistered firm. BD’s minor works FAQ says the person who arranged the works is responsible for appointing the prescribed professionals and contractors. That person may be the owner, an occupant, an owners’ corporation, a property management company, or a professional or contractor. Anyone who knowingly fails to appoint them may be prosecuted.
• Checking the company but not the item. An RMWC registered for one type of work cannot take on another.
• Treating minor works as exempt. Works outside the designated items do not use this system.
• Mixing up window schemes. Window works under a statutory notice follow the Mandatory Window Inspection Scheme. BD’s MWCS pamphlet on windows covers window works under this system.

For Class I, some practices in our architecture directory say on their own websites that they provide Authorized Persons. A listing is not a Buildings Department appointment. ranked.hk is not the Buildings Department, and this guide is not legal advice.