Rooftop Structure on a Single-Staircase Composite Building - Regularise or Remove?

Regulatory starting point. The structure is a building, not a temporary structure: it has a steel frame, blockwork walls, a permanent roof, is enclosed, and is used for storage. It was erected without approval under section 14(1) of the Buildings Ordinance and without consent to commence, so it is unauthorised building works and the Building Authority may serve an order under section 24 requiring removal. What the owner calls the structure does not change the test, which is the physical character and permanence of the works.

Retention is possible in principle, but only on compliance. Three technical issues govern the outcome here:

1. Means of escape. The only access is a steep ladder from a stair half-landing. A ladder is not an acceptable escape route, and the structure projects over the stair enclosure and reduces headroom. A storey used for storage needs a proper route with fire-rated construction, and the common staircase cannot be obstructed or encroached upon.
2. Fire resisting construction. The roof over the stair enclosure is part of the protected route and must retain its fire resistance. A steel frame and metal roof will not necessarily deliver the required period, and the storage fire load sits directly over the single means of escape for the whole building.
3. Structure. The existing frame must be justified against current loading and wind provisions, with proper connections and restraint to the existing roof; an Authorized Person cannot certify an existing frame that has never been analysed or inspected.

There is also the Fire Safety Direction: retaining a structure that obstructs the escape route makes compliance harder, and the two processes will be read together. My advice is that retention is only worth pursuing if the escape route, stair enclosure and structure can all be made compliant - on these facts, removal is the realistic outcome.

No - it converts one defect into another. A common staircase is a protected escape route. Cutting a door into it from a storage room introduces a fire load and a penetration directly into the protected enclosure, and a store opening onto a staircase without a protected lobby is not acceptable. The staircase must remain a sterile, protected route; the room would need its own protected approach, which the geometry of this building does not provide.

The change also does nothing about the other two issues:

• Fire resistance of the enclosure. A new opening in the stair enclosure wall must be protected by fire-rated construction and a self-closing fire door of the required rating, and the wall must be made good to the full required period. Blockwork of unknown thickness and the metal roof above will not automatically achieve this, and the room sits over the top of the enclosure where the roof itself forms part of the separation.
• Structure and loading. The new opening may cut a loadbearing or bracing element, and the frame still needs justification.

There is a further, separate problem: the staircase and roof are common parts. Altering them requires authority under the deed of mutual covenant and the Building Management Ordinance, not merely the support of the Owners' Corporation in principle; a resolution and proper consent will be needed, and neighbouring owners may object because their escape route is being compromised.

Practically, the proposal simply relocates the fire risk. I would not submit it, and I would tell the client plainly that the answer is a properly protected independent route that this building cannot provide, or removal.

Decline to certify what cannot be certified. When an Authorized Person submits plans, they are making a professional statement that the works, if built to those plans, would comply with the Buildings Ordinance and the relevant regulations and codes. Lodging plans for a structure that obstructs the only escape route and cannot achieve the required fire resistance would be a false statement, whatever the Owners' Corporation is willing to sign.

Practical steps:

• Put the advice in writing: the specific non-compliances, the fact that the ladder is not an acceptable escape route, and that the stair enclosure is compromised. Give the client the alternatives (removal, or a scheme that genuinely resolves access and separation) with cost and programme implications.
• Do not rely on 'the Department rarely checks'. The Building Authority audits submissions and site works, and the Fire Services Department is consulted on escape provisions; the Fire Safety Direction has already put this building on the record.
• Do not accept a signed resolution as a substitute for technical compliance. Deed of mutual covenant consent is a separate requirement that does not cure a Building Ordinance breach - and obtaining consent by telling owners the scheme is approvable would compound the problem.
• If the client instructs you to lodge non-compliant plans, decline and record the instruction. Consider whether you should resign the appointment and, if the structure presents a danger to occupants, whether a report to the Building Authority is warranted.
• Keep a contemporaneous file: site records, photographs, correspondence, and the reasoning behind each recommendation. This is the evidence that will matter if the works are later investigated or a complaint is made to your registration board.