Sprinkler hazard classification sorts each area of a building by its fire load: how much combustible material it holds and how quickly a fire would spread. The class then sets almost everything else in the design: the design density (water per square metre), the area of operation the system must supply at once, sprinkler spacing and the water supply. In Singapore it follows SS CP 52, which the SCDF Fire Code requires. The code runs from light occupancies through Ordinary Hazard groups to high hazard process and storage. Getting the class right first matters because a wrong class makes every calculation after it wrong.
This guide explains the concept and the SCDF Fire Code 2023 requirements as published in October 2026. SS CP 52 is a copyrighted Singapore Standard: buy the current edition from the Singapore Standards eShop and design to the edition that applies to your project. This guide does not reproduce its tables.
Which buildings need sprinklers
Before classifying, confirm sprinklers are required at all. Clause 6.4.1 of the SCDF Fire Code 2023 sets the main triggers:
| Trigger | Requirement |
|---|---|
| Compartmentation | Sprinklers wherever the compartment limits in Table 3.2A cannot be met |
| Height | Every storey of a building over 24 m habitable height, except Purpose Groups I and II |
| Basements | All basement storeys, except Purpose Groups I and II; cross-ventilated basements and some residential car parks can be relaxed under conditions |
| Factories and warehouses | Triggered by, among others, more than 3 storeys, a large compartment area or cubical extent, engineered smoke control or high-bay storage |
| Atriums | Sprinklers up to 18 m high; above that, water monitors, deluge or extended-throw sprinklers |
| Mixed residential towers | Non-residential parts above 24 m, and those not compartmented from the basement, under the conditions in the clause |
How the hazard classes are arranged
SS CP 52 groups occupancies broadly like this. Use the code for the exact names, criteria and examples:
| Group | Typical character | What changes in the design |
|---|---|---|
| Light hazard | Low fire load, little combustible material, such as some residential and institutional areas | The lowest density and smallest area of operation |
| Ordinary Hazard groups (the Fire Code refers to Groups I, II and III) | Moderate fire load, from offices and restaurants up to retail, car parks and some manufacturing | Density and area of operation step up with each group |
| High hazard: process | Processes with fast-spreading fires, such as some plastics and rubber manufacturing | Much higher densities and larger design areas |
| High hazard: storage | Goods stored high or densely, where storage height and arrangement drive the design | Design depends on the commodity, storage height and method; in-rack sprinklers may be needed |
Water demand by Ordinary Hazard group
The Fire Code does not reproduce SS CP 52's density tables, but clause 6.4.7, on reduced water storage for existing buildings up to 60 m, quotes the system demands from SS CP 52:
| Ordinary Hazard group | System demand quoted in the Fire Code | Tank, reliable inflow | Tank, unreliable inflow |
|---|---|---|---|
| Group I | 540 L/min | 12.5 m³ | 16.2 m³ |
| Group II | 1,000 L/min | 25.0 m³ | 30.0 m³ |
| Group III | 1,350 L/min | 37.5 m³ | 40.5 m³ |
These tank figures apply only to that reduced-storage case for existing buildings, and each is the greater of the table value or 30 minutes of pump running. New buildings, storage risks and chemical processes are excluded. New designs are proven by full hydraulic calculation. The Fire Code also allows combined sprinkler and wet riser systems for ordinary hazard classifications (clause 6.4.8).
How to classify a building, step by step
- List every area and its use. Use the architectural plans and the owner's intended use, not just room names.
- Note what is stored and how high. Storage height and arrangement can move an area into a high hazard storage class.
- Assign a class to each area using SS CP 52's criteria and examples.
- Check boundaries between classes. Decide where one class ends and another begins, and whether a higher class needs to extend into neighbouring areas.
- Find the most demanding area. It sets the water supply and the pump duty.
- Record the basis. Write the classification and its reasons into the design report, so the reviewer and future tenants can see it.
Common mistakes
- Classifying by room name. A "store" might hold paper archives or flammable goods. Classify by what is there.
- Ignoring storage height. Racking added after handover can push an area out of the class it was designed for.
- Carrying values from an old job. Densities and areas come from the edition in force, not a previous project.
- Forgetting tenant changes. A retail fit-out or a change of use can need re-classification and a new calculation.
- One class for the whole building. Mixed-use buildings need each area classified separately.
- Missing the supply check. The most demanding area must be supplied, not the largest.
Related guides
- Sprinkler hydraulic calculations
- Wet and dry riser requirements in Singapore
- Fire hose reel requirements in Singapore
- Fire protection tender estimation
How Newham can help
Newham's fire protection design service prepares sprinkler layouts to SS CP 52 across hazard classifications, with hydraulic calculations, fire pump selection and submission drawings formatted for SCDF. Newham prepares the design and drawings. It is not a QP: where the submission needs Professional Engineer endorsement, Newham coordinates review by a Singapore-registered PE, quoted separately. Book a call to scope a package.