The Restaurant That Would Not Fit
A 1962 six-storey composite building in Mong Kok has one 1,050 mm wide staircase serving all floors, no sprinkler system, and a cockloft and an unauthorised mezzanine that have existed since the 1980s. Your client, the new owner of the ground floor and mezzanine, wants a 140-seat restaurant: 120 m² at ground level and 60 m² on the mezzanine, with an open kitchen at the rear. The upper floors are residential. You calculate the occupant capacity at 120 persons; the single-direction travel distance from the far corner of the mezzanine is 21 m against a 15 m limit for this occupancy, while the 1,050 mm stair is adequate at 5 mm per person. The client instructs you to submit the mezzanine as 'storage' to avoid the travel-distance problem and to start fitting-out next month, saying the previous restaurant on this site operated for years without a problem.
1. Can this restaurant be approved as proposed, and by what route? Address the travel distance, the unauthorised mezzanine and the residential floors above.
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As proposed, no. The works are building works requiring approval of plans and consent to commence under section 14(1) of the Buildings Ordinance, and because the use changes to food and beverage the applicable benchmark is the Code of Practice for Fire Safety in Buildings. A composite building of this age also engages the fire safety requirements for the common parts, and the change of use strengthens the Buildings Authority's power to require upgrading of the existing building.
The 21 m single-direction travel distance against a 15 m limit is a failure, not a rounding issue. The mezzanine cannot be approved as a dining area on those numbers. Separately, the mezzanine itself is unauthorised: labelling it 'storage' does not regularise it, and if it is to be used for any purpose it must either be removed or submitted for approval with structural justification - restaurant and assembly floor loadings are materially higher than the residential loading the original slab was designed for.
The single 1,050 mm staircase is width-adequate but protection-inadequate for a restaurant under a residential building. It will need a fire-rated enclosure and, depending on the assessment, a protected lobby, with no unprotected openings from the restaurant into the stair. The kitchen requires fire separation from the dining area and from the residential part, and the discharge of cooking fumes must satisfy the relevant air pollution controls and the Food and Environmental Hygiene Department's licensing requirements.
The AP should present the client with a written options appraisal - sprinkler protection, a second escape route, or a reduced mezzanine - with costs and programme, rather than simply returning the plans.
2. The client instructs you to submit the mezzanine as 'storage'. How should you respond, professionally and practically?
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Refuse, clearly and in writing, and explain why the instruction cannot be followed.
Submitting a plan or form that describes a dining area as storage is a misdescription of the intended use made to obtain statutory approval. It exposes the client and the practice to the risk that any approval is invalid or liable to be revoked, to action by the Buildings Department against unauthorised building works, and potentially to offence provisions for false statements in a submission. The approved storage would in any event be used as dining, so the fire safety risk the Code is designed to control would exist unmitigated - with residential occupants above.
Professionally, registration carries an obligation to act with integrity and within the law, and the professional conduct code does not permit an architect to sign or submit something the architect knows to be untrue. 'The previous restaurant operated for years' is not a defence: enforcement history is not compliance, and a change of owner and a new fit-out is exactly when the Buildings Department will look.
Practically: put the refusal in writing with reasons; restate the compliant options and their costs; record that the client was warned; confirm what you will and will not submit. If the client insists, say plainly that you cannot act on that instruction and consider whether the retainer can continue - check the appointment for suspension and termination provisions and for fees already earned. Do not drift into silence or 'let the contractor deal with it', because silence will later look like acquiescence.
Notify your professional indemnity insurer if a claim or complaint is foreseeable, and keep the file note contemporaneous.
3. Set out compliant design options with indicative implications, and explain what would make each work.
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There are four credible routes, and they can be combined.
First, sprinkler the premises and the escape route. Code-compliant sprinkler protection allows increased travel distance and can support a single staircase in defined circumstances, which directly addresses the 21 m figure. It requires a dedicated supply, tank and pump space, and a maintained system; it also adds to the fit-out cost and the licensing conditions. On a 180 m² premises the capital cost is usually modest compared with losing the mezzanine.
Second, provide a second means of escape from the mezzanine - typically an external staircase through the rear light well or an protected route to a second stair - so that travel is no longer single-direction. This depends on whether the rear light well and boundary setbacks allow it, and on the neighbour's consent if it overhangs.
Third, reduce the mezzanine dining area so that the furthest point is within the single-direction limit, relocating storage and toilets to the far zone. This is the cheapest route but reduces the 140 covers, which drives the client's business case.
Fourth, reduce the overall occupant capacity by re-planning seating and the open kitchen so the mezzanine falls below the threshold at which the stricter travel provisions bite.
In every option the staircase enclosure, the separation from the residential floors and the kitchen fire separation must be resolved, and the unauthorised mezzanine must be structurally justified for its loading. Recommend a fire engineering assessment with the RSE and, if needed, a fire safety specialist, and put the options to the client with cost, programme and cover count.