Reference table

Occupancy Hazard Classification Reference

Name: Occupancy Hazard Classification Reference
Keywords: NFPA 13 occupancy hazard classification

Screen common occupancy examples against broad NFPA 13 hazard classes for early sprinkler design scoping and calculator setup.

NFPA 13 occupancy hazard classification6 rows2 linked calculators

Rows

Reference values

Columns

Lookup fields

Linked tools

Calculators using this data

Page role

Use this page for a defined task before moving to the next project record.

Audience: Engineers, designers, reviewers, and technicians selecting calculator input values.
Job: Use this table to screen common occupancy examples before selecting a preliminary sprinkler hazard class.
Evidence: Match the actual occupancy use, not only the room name shown on drawings. Review storage height, commodity, process, and fuel loading before accepting the likely hazard class.
Output: Selected Representative Occupancy Screening row carried into 2 calculator workflows.
Next: Choose the matching row, review selection checks, then open the calculator or worksheet that consumes the value.

Source governance

Record how this table is used before carrying a value into a calculator, worksheet, or authority workflow.

Governance item	Record	Use boundary
Source class	Design-basis selection aid	Use the table as a controlled reference input, not as an adoption or approval database.
Last review basis	Static registry review	Re-check adopted standards, manufacturer data, and project criteria before final use.
Known limit	Occupancy, storage, commodity, and local amendment context can control the final basis.	Escalate unresolved code, listing, or jurisdiction questions to the project record.
Downstream record	Occupancy Hazard Classifier Calculator, Design Density Lookup Calculator, Hazard Classification and Density Setup Worksheet, NFPA 13 Hydraulic Design Worksheet	Keep selected rows with the worksheet, calculation package, or authority record.

Reference table structure

Use these fields to filter the table, select a value, and retain the basis with the calculation record.

Rows

Filter fields

Occupancy

Value columns

Likely Hazard Class, Screening Note

Table area	Values	Engineering use
Query examples	Occupancy = Offices; Occupancy = Restaurants dining areas; Occupancy = Parking garages	Use these values as table filters before carrying a row into a calculator.
Related calculators	Occupancy Hazard Classifier Calculator, Design Density Lookup Calculator	Selected rows become calculation inputs or reasonableness checks for the linked tools.
Related worksheets	Hazard Classification and Density Setup Worksheet	Worksheet records preserve the selected value with the project assumption trail.

Reference table use

Use the table as controlled input data: select the row, verify the condition, and carry the value to the related calculator.

Usage context

1Use this table to screen common occupancy examples before selecting a preliminary sprinkler hazard class.
2Treat the result as a scoping aid that must be checked against storage, process, commodity, and AHJ/project criteria.
3Carry the hazard class into density lookup and hazard-density setup only with the occupancy evidence that justified the selection.

Selection rules

1Match the actual occupancy use, not only the room name shown on drawings.
2Review storage height, commodity, process, and fuel loading before accepting the likely hazard class.
3Use the screening note as a reason to escalate uncertain classifications, not as final AHJ approval.

Review checks

1Occupancy evidence supports the screened hazard class and identifies uncertain storage or process conditions.
2Density lookup uses the same hazard class selected from the occupancy screen.
3The result is marked preliminary until project-specific review and AHJ context are resolved.

Reference field	How to use it	Related tools
Occupancy	Use this field to identify the matching project condition.	Occupancy Hazard Classifier Calculator, Design Density Lookup Calculator, Hazard Classification and Density Setup Worksheet
Likely Hazard Class	Carry this value into the downstream calculator with the displayed units and label.	Occupancy Hazard Classifier Calculator, Design Density Lookup Calculator, Hazard Classification and Density Setup Worksheet
Screening Note	Carry this value into the downstream calculator with the displayed units and label.	Occupancy Hazard Classifier Calculator, Design Density Lookup Calculator, Hazard Classification and Density Setup Worksheet

Selection examples

Use these examples to choose a row deliberately before carrying the value into a calculator or worksheet.

Scenario	Row choice	Reason	Downstream use
An office area has typical desks, records, and low storage.	Use the occupancy row that matches office use only after confirming fuel load and storage are ordinary for that space.	Occupancy use starts the hazard screen but does not override actual contents.	Carry the screened hazard class into density lookup and hazard-density setup with the occupancy evidence.
A stock room sits inside an otherwise light-hazard tenant space.	Screen the stock room separately instead of applying the office row to the entire suite.	Storage height, packaging, and commodity can change the hazard class.	Create a separate hazard-density record for the storage area before hydraulic demand screening.
A maintenance or production area includes oils, process material, or higher fuel load.	Use the higher-challenge row or flag the classification for engineering/AHJ review.	Process and fuel load can control classification more than the room name.	Resolve the hazard class before selecting density-area criteria or sprinkler coverage assumptions.

Separating mixed occupancy hazard classes

Assumptions

1A tenant suite includes office space, a stock room, and a small maintenance shop.
2Each area has different occupancy use, fuel load, and storage or process conditions.
3The hazard class will feed density-area lookup and sprinkler coverage checks.

Steps

1Screen the office area from occupancy use and typical contents.
2Review the stock room separately for storage height, commodity, and packaging.
3Review the maintenance shop for process material, oils, or higher fuel load.
4Carry each resolved hazard class into its own density-area basis before hydraulic demand screening.

Result

The workpaper may produce multiple hazard classes in one tenant suite. That is better than hiding storage or process risk under one broad occupancy name.

Misuse warnings

1Do not substitute building code occupancy group for sprinkler hazard class without reviewing contents and use.
2Do not apply one hazard class across mixed office, storage, and process areas unless the evidence supports it.
3Do not carry a preliminary hazard class into density lookup when storage, fuel load, or AHJ criteria are unresolved.

Representative Occupancy Screening

Occupancy	Likely Hazard Class	Screening Note
Offices	Light Hazard	Low fuel loading and low combustibility
Restaurants dining areas	Light Hazard	Public areas with limited fuel load
Parking garages	Ordinary Hazard Group 1	Vehicle storage with moderate combustibility
Manufacturing, moderate load	Ordinary Hazard Group 2	Combustible process or storage density
Printing plants	Extra Hazard Group 1	High challenge process with combustible materials
Flammable liquid processing	Extra Hazard Group 2	Severe fuel challenge requiring specialist review

Engineering disclaimer

NFPA in USA provides engineering workpapers, calculation checks, and reference tables for project screening and coordination. Final design decisions, code interpretations, submittals, and acceptance records must be completed by qualified professionals and verified against the adopted code, project criteria, listings, and Authority Having Jurisdiction requirements. This site does not issue signed or sealed engineering documents.

Tools and workflows that use this table

Occupancy Hazard Classifier Calculator Design Density Lookup Calculator Hazard Classification and Density Setup Worksheet NFPA 13 Hydraulic Design Worksheet

FAQ

How should this hazard classification table be used?+

Use it as an engineering reference source for selecting values, checking assumptions, and documenting the basis carried into a calculator or worksheet.

Can this table replace the sealed project record?+

No. Values still need to be checked against the adopted standard, manufacturer data, project specifications, and Authority Having Jurisdiction requirements before they are used in final documents.