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Within the context of building construction and building codes, "occupancy" refers to the use, or intended use, of a building, or portion of a building, for the shelter or support of persons, animals or property. [1] A closely related meaning is the number of units in such a building that are rented, leased, or otherwise in use. Lack of occupancy, in this sense, is known as "vacancy".


Building codes

It is possible to have multiple occupancies (or building uses) within one building. For example, a high-rise building can have retail stores occupying the lower levels, while the upper levels are residential. Different occupancies within a building are separated by a fire barrier [2] with a defined fire-resistance rating. It is common for a penetration (such as a fire door) to have a fire protection rating lower than the wall fire–resistance rating in which it is installed. [3] For example, a two-hour fire separation normally requires fire doors rated at 90 minutes.

For some high challenge occupancies, [4] the code requirements for an occupancy separation are more stringent than for other fire barriers, even with an identical fire resistance rating. In this case, an occupancy separation with a two-hour fire-resistance rating may not be able to "de-rate" its closures, such fire doors and firestops. For example, a two-hour rated "high challenge fire wall" [5] requires two-hour rated fire doors.

Firestops in occupancy separations are also more likely to require an equal fire protection rating (a fire resistance rating for closures). They also must provide a temperature rating ensuring that the components of the firestop systems, including the penetrants are not permitted to rise in temperature above 140°C (284°F) on average or 180°C (356°F) at any single point, to lower the likelihood of auto-ignition on the unexposed side. In this manner, occupancy separations are treated similarly to fire walls which are structurally stable in case of a fire, thus limiting the danger of fire-induced building collapse.

In this sense, there are two occupancies in many single-family homes: the garage and the living space of the home. Because automobile gasoline is flammable, an occupancy separation is often required between the two should there be a vehicle fire. Water heaters and central heating are often placed in this space as well for their use of natural gas, propane, or other fossil fuels in combustion. This also helps to prevent carbon monoxide poisoning.

Building utilization

The interior of a vacant building showing signs of vandalism and decay Granger Nurse.jpg
The interior of a vacant building showing signs of vandalism and decay

Occupancy can also refer to the number of units in use, such as hotel rooms, apartment flats, or offices. When a motel is at full occupancy, it is common practice to turn on a NO VACANCY neon sign. Completely vacant buildings can also attract crime. A 2017 study found that demolishing vacant buildings "reduce crime by about 8 percent on the block group in question and 5 percent on nearby block groups". [6]

Occupancy can also refer to the number of persons using an undivided space, such as a meeting room, ballroom, auditorium, or stadium. As with building codes, fire protection authorities often set a limit on the number of people that can occupy a space at one time. These limits are established primarily to allow all occupants safe passage through exits, but can also be employed to preserve the integrity of a structure.

An occupancy sensor is a device that can tell if someone is in a room, and is often used in home automation and security systems. These are typically more advanced than motion sensors, which can only detect motion.

Other meanings

In transport engineering, occupancy can refer to:

  1. The number of passengers occupying a vehicle
  2. The percentage of time in which a detector is occupied by a vehicle
  3. The average number of particles occupying a state

In football, occupancy can refer to:

  1. A team that does not currently have a manager, a president, or a home stadium

See also

Related Research Articles

Firewall (construction) Barrier used to prevent the spread of fire through or between structures

A firewall is a fire-resistant barrier used to prevent the spread of fire. Firewalls are built between or through buildings, structures, or electrical substation transformers, or within an aircraft or vehicle.

Drywall Panel made of gypsum, used in interior construction

Drywall is a panel made of calcium sulfate dihydrate (gypsum), with or without additives, typically extruded between thick sheets of facer and backer paper, used in the construction of interior walls and ceilings. The plaster is mixed with fiber, plasticizer, foaming agent, and various additives that can reduce mildew, flammability, and water absorption.

Fire safety Practices intended to reduce the destruction caused by fire

Fire safety is the set of practices intended to reduce the destruction caused by fire. Fire safety measures include those that are intended to prevent ignition of an uncontrolled fire, and those that are used to limit the development and effects of a fire after it starts.

The publication Life Safety Code, known as NFPA 101, is a consensus standard widely adopted in the United States. It is administered, trademarked, copyrighted, and published by the National Fire Protection Association and, like many NFPA documents, is systematically revised on a three-year cycle.

Fire door

A fire door is a door with a fire-resistance rating used as part of a passive fire protection system to reduce the spread of fire and smoke between separate compartments of a structure and to enable safe egress from a building or structure or ship. In North American building codes, it, along with fire dampers, is often referred to as a closure, which can be derated compared against the fire separation that contains it, provided that this barrier is not a firewall or an occupancy separation. In Europe national standards for fire doors have been harmonised with the introduction of the new standard EN 16034, which refers to fire doors as fire-resisting door sets. Starting September 2016, a common CE marking procedure was available abolishing trade barriers within the European Union for these types of products. In the UK, it is Part B of the Building Regulations that sets out the minimum requirements for the fire protection that must be implemented in all dwellings this includes the use of fire doors. All fire doors must be installed with the appropriate fire resistant fittings, such as the frame and door hardware, for it to fully comply with any fire regulations.

The International Building Code (IBC) is a model building code developed by the International Code Council (ICC). It has been adopted for use as a base code standard by most jurisdictions in the United States. The IBC addresses both health and safety concerns for buildings based upon prescriptive and performance related requirements. The IBC is fully compatible with all other published ICC codes. The code provisions are intended to protect public health and safety while avoiding both unnecessary costs and preferential treatment of specific materials or methods of construction. However, a 2019 New York Times story revealed a secret agreement with the National Association of Home Builders that allowed the industry group, which represents the construction industry, to limit improvements in the code that would make buildings more environmentally sustainable and resistant to natural disasters, prompting a congressional investigation.


Fireproofing is rendering something resistant to fire, or incombustible; or material for use in making anything fire-proof. It is a passive fire protection measure. "Fireproof" or "fireproofing" can be used as a noun, verb or adjective; it may be hyphenated ("fire-proof").

An intumescent is a substance that swells as a result of heat exposure, thus leading to an increase in volume and decrease in density. Intumescents are typically used in passive fire protection and require listing, approval, and compliance in their installed configurations in order to comply with the national building codes and laws.

Fire protection

Fire protection is the study and practice of mitigating the unwanted effects of potentially destructive fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of mitigating systems. In structures, be they land-based, offshore or even ships, the owners and operators are responsible to maintain their facilities in accordance with a design-basis that is rooted in laws, including the local building code and fire code, which are enforced by the Authority Having Jurisdiction.

A firestop or fire-stopping is a form of passive fire protection that is used to seal around openings and between joints in a fire-resistance-rated wall or floor assembly. Firestops are designed to maintain the fireproofing of a wall or floor assembly allowing it to impede the spread of fire and smoke.

Listing and approval use and compliance is the activity of adhering to specific conformance testing requirements to establish minimum performance for safety-related products and materials. The conformance could be for an active certification listing or for an approval that has been issued by an organization that is accredited both for testing and product certification. Such organizations include Underwriters Laboratories, FM Global, or the Deutsches Institut für Bautechnik (DIBt).

Passive fire protection

Passive fire protection (PFP) is an integral component of the components of structural fire protection and fire safety in a building. PFP attempts to contain fires or slow the spread, such as by fire-resistant walls, floors, and doors. PFP systems must comply with the associated listing and approval use and compliance in order to provide the effectiveness expected by building codes.

Firestop pillow

Firestop pillows are passive fire protection items used for firestopping holes to achieve fireproofing. The various kinds of firestop pillows are intended to slow the spread of fire. They are often used to meet fire-resistance ratings in conduits that need frequent access.

A fire-resistance rating typically means the duration for which a passive fire protection system can withstand a standard fire resistance test. This can be quantified simply as a measure of time, or it may entail a host of other criteria, involving other evidence of functionality or fitness for purpose.

Fire test

A fire test is a means of determining whether fire protection products meet minimum performance criteria as set out in a building code or other applicable legislation. Successful tests in laboratories holding national accreditation for testing and certification result in the issuance of a certification listing. The listing is public domain, whereas the test report itself is proprietary information belonging to the test sponsor.

Area of refuge Location in a building designed to hold occupants during a fire or other emergency

An area of refuge is a location in a building designed to hold occupants during a fire or other emergency, when evacuation may not be safe or possible. Occupants can wait there until rescued or relieved by firefighters. This can apply to the following:

Grease duct

A grease duct is a duct that is specifically designed to vent grease-laden flammable vapors from commercial cooking equipment such as stoves, deep fryers, and woks to the outside of a building or mobile food preparation trailer. Grease ducts are regulated both in terms of their construction and maintenance, forming part of the building's passive fire protection system. The cleaning schedule is typically dictated by fire code or related safety regulations, and evidence of compliance must be kept on file by the owner.

A penetration, in firestopping, is an opening, such as one created by the use of a cast-in-place sleeve, in a wall or floor assembly required to have a fire-resistance rating, for the purpose of accommodating the passage of a mechanical, electrical or structural penetrant. The penetration may or may not contain a firestop system. A penetration is not a penetrant. A penetration may or may not include a penetrant.

Fire damper

Fire dampers are passive fire protection products used in heating, ventilation, and air conditioning (HVAC) ducts to prevent the spread of fire inside the ductwork through fire-resistance rated walls and floors. Fire/smoke dampers are similar to fire dampers in fire resistance rating, and also prevent the spread of smoke inside the ducts. When a rise in temperature occurs, the fire damper closes, usually activated by a thermal element which melts at temperatures higher than ambient but low enough to indicate the presence of a fire, allowing springs to close the damper blades. Fire dampers can also close following receipt of an electrical signal from a fire alarm system utilising detectors remote from the damper, indicating the sensing of heat or smoke in the building occupied spaces or in the HVAC duct system.

Penetrant (mechanical, electrical, or structural)

Penetrants, or penetrating items, are the mechanical, electrical or structural items that pass through an opening in a wall or floor, such as pipes, electrical conduits, ducting, electrical cables and cable trays, or structural steel beams and columns. When these items pierce a wall or floor assembly, they create a space between the penetrant and the surrounding structure, which can become an avenue for the spread of fire between rooms or floors. Modern building codes generally require a service penetration firestop to seal the openings around penetrants, in order to restore the fire-resistance rating of the parent assembly.


  1. The Free Dictionary
  2. NFPA 5000 Building Construction and Safety Code 2006 Edition, Chapter 6 Classification of Occupancy, Classification of Hazard of Contents, and Special Operations section 6.2.4
  3. NFPA 5000 Building Construction and Safety Code 2006 Edition, Chapter 8 Fire-Resistive Materials and Construction, Table 8.7.2 Minimum Fire Protection Ratings for Opening Protectives in Fire Resistance–Rated Assemblies
  4. NFPA 5000 Building Construction and Safety Code 2006 Edition / Chapter 8 Fire-Resistive Materials and Construction, Table 8.7.2 Minimum Fire Protection Ratings for Opening Protectives in Fire Resistance–Rated Assemblies
  5. NFPA 5000 Building Construction and Safety Code 2006 Edition, section 8.3
  6. Stacy, Christina Plerhoples (2018). "The effect of vacant building demolitions on crime under depopulation". Journal of Regional Science. 58: 100–115. doi:10.1111/jors.12350. ISSN   1467-9787.