Case Study: Ordering Constraints and Reaching a Defensible Position
The Case Study domain is the integrative ground of Paper 5. You are handed a Hong Kong development scenario - a site, a client brief, a set of expectations - and asked to reach a defensible professional position. The paper rewards the candidate who ranks the governing instruments, quantifies the binding constraint and then acts on it, not one who recites regulations without ordering them.
Rank the constraints before you design
- Government lease or Conditions of Grant: permitted user, GFA cap, building height, setback. This binds contractually.
- Outline Zoning Plan under the Town Planning Ordinance (Cap. 131): zoning, plot ratio and site coverage, with a s.16 application to the Town Planning Board where the scheme departs from the plan.
- Buildings Ordinance (Cap. 123) and its regulations: Building (Planning) Regulations for site coverage, plot ratio, open space, lighting and ventilation; Building (Construction) Regulations for structure and fire resistance.
- Codes and PNAPs: Code of Practice for Fire Safety in Buildings 2011; PNAP APP-152 on sustainable building design and GFA concessions.
The strictest instrument governs, and each breach carries a different remedy.
Worked example
A 1,000 m² site is zoned R(A) with a maximum domestic plot ratio of 7.5. The lease caps GFA at 6,000 m². The client's scheme measures 7,100 m².
Reasoning: the planning ceiling is 1,000 × 7.5 = 7,500 m², so the OZP is not the obstacle here. The lease cap of 6,000 m² binds, and the scheme exceeds it by 1,100 m². Exceeding the lease is not a Building Authority matter - the Buildings Department administers the Ordinance, not the lease - but the Government as landlord can withhold consent and demand premium, so the exposure is real. Options: cut the scheme to 6,000 m², or apply to modify the lease and pay premium, confirming separately that no s.16 permission is needed. Answer the client in square metres and dollars.
Traps that cost marks
- Treating an OZP plot ratio as an entitlement; it is a ceiling, and the difference between "always permitted" and "permission required" changes the whole programme.
- Adding abutting street area to the site area without first confirming the site class under the Building (Planning) Regulations.
- Assuming a change of use needs only planning permission, when the lease may restrict user independently.
- Answering with process ("submit plans to the Building Authority") when the question asks which figure governs.
- Ignoring programme, cost and buildability when the brief asks for a recommendation, not a compliance statement.