Change of use and renovation (Parts 10 and 11) (Powers and Duties of Chief Building Officials)

Last updated October 22, 2026

Values this chapter turns on

existence needed for Part 11 to apply: 5 years; existence needed for Part 11 to apply
occupant load increase that reduces performance: 15%; occupant load increase that reduces performance
combustible extension limit before a reduction: 4 storeys; combustible extension limit before a reduction
scale of the construction index: 1 to 8; scale of the construction index

Parts 10 and 11 of Division B govern existing buildings. Part 10 applies when a change of use needs a permit under section 10 of the Act. Part 11 applies to renovation of buildings that have existed for at least five years. A chief building official uses both to decide how much upgrading an existing building needs. The central idea in both is the "performance level": the level at which an existing building functions with respect to its building systems (OBC Div. A 1.4.1.2.). Work must not make it worse; if it would, compensating construction is required.

Change of use: scope, classification and performance level

Part 10 applies to existing buildings requiring a s. 10 permit (OBC Div. A 1.3.3.3A.). Besides an ordinary change between major occupancies, certain changes are deemed a change in major occupancy: one Group C suite into more than one, assembly suites into gaming premises, farm buildings to non-Group G use or to G-1, any building to a post-disaster building or a retirement home, and any change where the previous major occupancy cannot be determined (OBC Div. B 10.1.1.2.).

The building is classified by major occupancy under Part 2 or Subsection 3.1.2. (OBC Div. B 10.2.1.1.), and by construction index and hazard index as in Part 11 (OBC Div. B 10.2.1.2.). Group G may be calculated as if F-2. The new occupancy must meet a listed set of provisions, for example Subsection 3.2.6., Sections 3.7., 3.11. and 3.12., and listed Part 9 items such as Sections 9.31. and 9.32. (OBC Div. B 10.3.1.1.).

Basic rule: performance after the change must not be less than before (OBC Div. B 10.3.2.1.). Under OBC Div. B 10.3.2.2. it is reduced where, among other things:

floor and roof framing cannot carry the new loads (unless the floor area is restricted and signs posted);
early warning and evacuation systems fall short of Table 10.3.2.2.-A;
the new major occupancy has a greater hazard index, unless the hazard index does not exceed the construction index;
a combustible building changes to residential where a new building would need noncombustible construction, unless it is sprinklered and not more than 6 storeys;
required fire separations between occupancies are missing;
sewage flow exceeds the system's capacity or prohibited sewage would be discharged;
a change to a retirement home lacks full sprinklering, a required voice communication system or self-closing doors.

Compliance alternatives may be used for change of use, but in a building less than five years old only for the requirements referenced in Sentences 10.3.2.2.(3) and (5) and Table 10.3.2.2.-B (OBC Div. B 10.4.1.1.).

Practice this topic

Renovation: classification and proposed construction

Part 11 applies to existing buildings that have existed for at least five years; if such a building has an addition less than five years old, Part 11 applies to the entire building (OBC Div. A 1.3.3.3B.). For extension, material alteration or repair, the proposed construction follows Section 11.3., and the performance level is evaluated with compensating construction under Section 11.4. (OBC Div. B 11.1.2.1.).

A "building system" is a complete major division of construction, such as structure, roofing, plumbing, sprinkler, sewage or electrical systems (OBC Div. B 11.1.1.2.). The construction index runs from 1 to 8 (OBC Div. A 1.4.1.2.).

Proposed construction	Rule
Altering or repairing an existing building system	performance level at least equal to before (11.3.1.1.)
New building system or extension of one	comply with the other Parts, except basic renovation and compliance alternatives (11.3.1.2.)
Extension of a building	Part 11 for the existing portion; the extension complies with other Parts (11.3.2.1.)
Basic renovation	reuse similar materials to keep character or heritage, if early warning, fire separations, structure and health are not harmed (11.3.3.1.)
Extensive renovation	where walls, ceilings, floors or roofs are substantially removed and replaced, structural and fire-resistance elements meet the other Parts (11.3.3.2.)
Plumbing	Part 7 applies to new or altered plumbing and plumbing adversely affected (11.3.4.1.)
Septic tank altered or replaced	Part 8 applies (11.3.5.1.)

Basic renovation of a B-3 occupancy, hotel or retirement home also needs Fire Code conformance. Extensive renovation of a storey in a building over 3 storeys that will contain Group C requires sprinklers, subject to an exception (OBC Div. B 11.3.3.2.).

Practice this topic

Performance level evaluation and compensating construction

Section 11.4. repeats the basic rule and requires compensating construction where performance would drop (OBC Div. B 11.4.1.1.). Main reduction triggers:

Trigger	Article
Structure inadequate after change of occupancy, occupant load up more than 15%, or higher live load	11.4.2.1.
Occupant load up more than 15%; or up 15% or less but beyond fire alarm or exit capacity thresholds	11.4.2.2.
Change to a major occupancy with a greater hazard index, and the deemed changes	11.4.2.3.
Plumbing adversely affected	11.4.2.4.
Sewage system affected or overloaded, including more bedrooms in a dwelling unit	11.4.2.5.
Combustible building extended to more than four storeys	11.4.2.6.

Compensating construction (OBC Div. B 11.4.3.1.) generally covers fire separations around the altered part and exits where the alteration affects them. Examples: strengthen or restrict and sign floors (OBC Div. B 11.4.3.2.); upgrade early warning and evacuation systems per Table 11.4.3.3. (OBC Div. B 11.4.3.3.); raise the construction index to at least the new hazard index (OBC Div. B 11.4.3.4.); upgrade plumbing or sewage systems to Part 7 or 8; sprinkler a combustible building extended beyond four storeys (OBC Div. B 11.4.3.7.).

Practice this topic

Compliance alternatives

A compliance alternative is a substitute, listed in Part 10 or 11, for a requirement elsewhere in Division B (OBC Div. A 1.4.1.2.). For requirements in Parts 3, 4, 6 or 8, the CBO must be satisfied that compliance is impracticable because of structural or construction difficulties or because it would harm a heritage building. For Parts 9 and 12, no such finding is needed (OBC Div. B 11.5.1.1.).

Practice this topic

Worked scenarios

Office to restaurant. Assume, for illustration, an existing building with a construction index of 4 changes to an occupancy with a hazard index of 5. The hazard index now exceeds the construction index, so performance is reduced; upgrading must bring the construction index up to at least 5.

Bedroom addition on septic. A house adds two bedrooms and the design sewage flow will exceed the existing tank's capacity. Performance is reduced under 11.4.2.5., and the sewage system must be upgraded to Part 8.

Heritage stair. A designer proposes a compliance alternative for a Part 3 stair requirement in a designated heritage building. The CBO must first be satisfied that compliance is impracticable because it would harm the heritage building.

Common traps

Part 11 starts at five years; a newer addition pulls the whole building in.
More than 15% occupant load increase is the structural and fire trigger.
Parts 3, 4, 6 and 8 need the CBO's impracticability finding; Parts 9 and 12 do not.

Chapter review

Chapter at a glance

One line per section: the idea to carry into the exam. Then the answers that most often catch candidates out.

Chapter at a glance: the key idea in each section
Section	Key idea
Change of use: scope, classification and performance level	Part 10 applies to existing buildings requiring a s. 10 permit.
Renovation: classification and proposed construction	Part 11 applies to existing buildings that have existed for at least five years; if such a building has an addition less than five years old, Part 11 applies to the entire…
Performance level evaluation and compensating construction	Section 11.4. repeats the basic rule and requires compensating construction where performance would drop.
Compliance alternatives	A compliance alternative is a substitute, listed in Part 10 or 11, for a requirement elsewhere in Division B. For requirements in Parts 3, 4, 6 or 8, the CBO must be satisfied…

Change of use: scope, classification and performance level
Part 10 applies to existing buildings requiring a s. 10 permit.
Renovation: classification and proposed construction
Part 11 applies to existing buildings that have existed for at least five years; if such a building has an addition less than five years old, Part 11 applies to the entire…
Performance level evaluation and compensating construction
Section 11.4. repeats the basic rule and requires compensating construction where performance would drop.
Compliance alternatives
A compliance alternative is a substitute, listed in Part 10 or 11, for a requirement elsewhere in Division B. For requirements in Parts 3, 4, 6 or 8, the CBO must be satisfied…

Usual exam traps

Part 11 starts at five years; a newer addition pulls the whole building in.
More than 15% occupant load increase is the structural and fire trigger.
Parts 3, 4, 6 and 8 need the CBO's impracticability finding; Parts 9 and 12 do not.

Practice this chapter

Questions on Change of use and renovation (Parts 10 and 11), in the exam format, every answer explained and cited to its article. Sign in to start; a free account gets the free questions.

Practice this chapter Free Powers and Duties of Chief Building Officials quiz

Code cited in this chapter

Based on the official 2024 Building Code Compendium on ontario.ca.

OBC Div. A 1.4.1.2.(1) Performance level
Performance level means the level of performance under which all or part of an existing building functions with respect to its building systems.
Open OBC Div. A 1.4.1.2.(1) in the code viewer
OBC Div. A 1.3.3.3A. Application of Part 10
(1)Part 10 of Division B applies to existing buildings requiring a permit under section 10 of the Act.
Open OBC Div. A 1.3.3.3A. in the code viewer
OBC Div. B 10.1.1.2. Change in Major Occupancy
(1)The following changes of use are also deemed to be a change in major occupancy for the purposes of this Part:
(a)a suite of a Group C major occupancy is converted into more than one suite of a Group C major occupancy,
(b)a suite or part of a suite of a Group A, Division 2 or Group A, Division 4 major occupancy is converted to a gaming premises,
(c)a farm building or part of a farm building is changed to another major occupancy other than a Group G major occupancy,
(d)a building or part of a building is changed to a post-disaster building,
(e)a building or part of a building is changed to a retirement home,
(f)the use of a building or part of a building is changed and the previous major occupancy of the building or part of the building cannot be determined, or
(g)a farm building or part of a farm building is changed to a Group G, Division 1 major occupancy.
Open OBC Div. B 10.1.1.2. in the code viewer
OBC Div. B 10.2.1.1. Classification of Major Occupancy
(1)Every existing building or part of it shall be classified according to its major occupancy in accordance with the requirements of Part 2 or Subsection 3.1.2.
Open OBC Div. B 10.2.1.1. in the code viewer
OBC Div. B 10.2.1.2. Classification According to Construction and Occupancy
(1)Except as provided in Sentence (2), for the purposes of this Part, existing buildings shall be classified as to their construction and occupancy as provided for in Sentence 11.2.1.1.(1).
(2)For the purpose of Parts 10 and 11, the calculation of the construction index and hazard index for Group G major occupancy is permitted to be based on Group F, Division 2 major occupancy.
Open OBC Div. B 10.2.1.2. in the code viewer
OBC Div. B 10.3.1.1. General
(1)Except as provided in Section 10.4., a building or part of a building subject to a change of major occupancy shall conform to the requirements of Subsection 3.2.6., Sections 3.7., 3.11. and 3.12., Sentences 6.3.1.1.(2) and 6.3.2.7.(1), Subsections 9.5.1. and 9.5.3., 9.5.3A. to 9.5.3F. and 9.5.4., Sentences 9.6.1.4.(3), (4), Article 9.7.2.3., Sentences 9.8.8.1.(4) to (8) and 9.9.10.1.(1) to (7), Subsection 9.10.17., Sections 9.31. and 9.32., Sentence 9.33.6.13.(7.1), and Subsections 9.34.1. to 9.34.3. as they apply to the new major occupancy that the building or part of a building is to support.
(2)Where a major occupancy is changed to a Group B, Division 2 major occupancy, heating, ventilating, and air conditioning systems shall conform to the requirements of Sentence 6.2.1.1.(1).
(3)Where a major occupancy is changed to a Group B, Division 3 major occupancy, ventilation, air circulation, and filtration systems, shall conform to the requirements of Sentence 6.2.1.1.(1).
Open OBC Div. B 10.3.1.1. in the code viewer
OBC Div. B 10.3.2.1. General
(1)The performance level of a building after the change of major occupancy shall not be less than the performance level prior to the change of major occupancy.
(2)For the purposes of Sentence (1), reduction of performance level shall be determined in accordance with Article 10.3.2.2.
(3)For the purpose of this Subsection, where a permit to construct a farm building has been applied for before January 1, 2025, the performance level of the farm building is permitted to be evaluated based on the applicable requirements of Ontario Regulation 332/12 (Building Code) made under the Act, as it read on December 31, 2024.
Open OBC Div. B 10.3.2.1. in the code viewer
OBC Div. B 10.3.2.2. Reduction in Performance Level
(1)Except as provided in Sentence (2), the performance level of a building or part of a building is reduced where the existing structural floor and roof framing systems and their supporting members are not adequate to support the proposed dead loads and live loads of the new major occupancy that the building is to support.
(2)The inadequacy of the existing structural floor or roof framing system and its supporting members to support the proposed dead loads and live loads does not reduce the performance level of the building if the portion of the floor affected by the proposed loads is restricted to the loading it will support and signs stating the restrictions are posted.
(3)Except as provided in Section 10.4., the performance level of a building or part of a building is reduced where the early warning and evacuation systems requirements of the building do not meet the early warning and evacuation systems requirements set out in Table 10.3.2.2.-A for the new major occupancy that the building is to support.
(4)Except as provided in Sentence (5), the performance level of an existing building is reduced where a change in use will result in a change of the major occupancy of all or part of an existing building to another major occupancy of a greater hazard index.
(5)Except as provided in Sentence (6), if the hazard index of the new major occupancy is greater than the hazard index of the existing major occupancy, the performance level is not reduced where the hazard index of the new major occupancy is not greater than the construction index of the existing building.
(6)Small or medium sized existing buildings as determined in Tables 11.2.1.1.-B to 11.2.1.1.-N facing multiple streets may be assigned a hazard index credit of 1, which may be subtracted from the hazard index of the new major occupancy provided,
(a)the building does not contain a Group B, Division 1, a Group C, or a Group F, Division 1 occupancy, and
(b)firefighting access complying with Articles 3.2.5.1. to 3.2.5.5. or Subsection 9.10.20. is provided.
(7)Except as provided in Sentence (8), the performance level of a building or part of a building is reduced in an existing building of combustible construction where,
(a)the occupancy is changed to a residential occupancy in all or part of the building, and
(b)if the building was new, it would have been required to be of noncombustible construction or to be constructed in accordance with Article 3.2.2.51. or 3.2.2.60.
(8)A change in the occupancy of a building or part of a building to a residential occupancy does not reduce the performance level of the building or part of the building where,
(a)the building is sprinklered, and
(b)the building does not exceed 6 storeys in building height.
(9)The performance level of a building or part of a building is reduced where the new major occupancy in an existing building of multiple occupancy is not separated from adjoining major occupancies by fire separations having fire-resistance ratings conforming to Article 3.1.3.1., Subsection 9.10.9. or Table 10.3.2.2.-B.
(10)The performance level of a building is reduced where the building after the change of major occupancy will not comply with Article 3.1.3.2. or 9.10.9.14.
(11)The performance level of a building or part of a building is reduced where, after a change of major occupancy,
(a)the total daily design sanitary sewage flow of the new major occupancy, calculated in accordance with Article 8.2.1.3., exceeds the capacity of any component of a sewage system serving the building, or
(b)the type or amount of sanitary sewage that will, under the new major occupancy, be discharged to a sewage system serving the building is prohibited by Article 8.1.3.1.
(12)The performance level of an existing building or part of an existing building is reduced where,
(a)the use of the building or part of the building is changed to a retirement home, and
(b)any of the following applies:
(i)the retirement home is not sprinklered throughout,
(ii)Clause 3.2.6.8.(1)(b) or
(c)as applicable, requires that a voice communication system conforming to Article 3.2.4.22. be provided in the building and such a system is not provided in the building, or
(iii) the retirement home contains one or more doors to suites or sleeping rooms not within suites, other than doors leading directly to the exterior, that are not equipped with self-closing devices.
Open OBC Div. B 10.3.2.2. in the code viewer

Show all 22 articles

OBC Div. B 10.4.1.1. Substitution
(1)Except as provided in Sentence (3), a compliance alternative to a requirement contained in Part 3, 4, 6 or 8 that is shown in Tables 11.5.1.1.-A, 11.5.1.1.-B, 11.5.1.1.-C, 11.5.1.1.-D/E or 11.5.1.1.-F may be substituted for the requirement where the chief building official is satisfied that compliance with the requirement is impracticable because,
(a)of structural or construction difficulties, or
(b)it is detrimental to the preservation of a heritage building.
(2)Except as provided in Sentence (3), a compliance alternative to a requirement contained in Part 9 or 12 shown in Tables 11.5.1.1.-C, 11.5.1.1.-D/E or 11.5.1.1.-F may be substituted for the requirement without satisfying the chief building official that the requirement is impracticable.
(3)Where the building has been in existence for less than five years, compliance alternatives may only be used in respect of requirements of this Division that are referenced in Sentences 10.3.2.2.(3), (5) and Table 10.3.2.2.-B.
Open OBC Div. B 10.4.1.1. in the code viewer
OBC Div. A 1.3.3.3B. Application of Part 11
(1)Except as provided in Sentence (2), Part 11 of Division B applies to the design and construction of existing buildings, or parts of existing buildings, that have been in existence for at least five years.
(2)If a building has been in existence for at least five years but includes an addition that has been in existence for less than five years, Part 11 of Division B applies to the entire building.
Open OBC Div. A 1.3.3.3B. in the code viewer
OBC Div. B 11.1.2.1. Extension, Material Alteration or Repair
(1)Where an existing building is subject to extension, material alteration or repair,
(a)the proposed construction shall comply with Section 11.3., and
(b)the performance level of the building shall be evaluated and compensating construction shall be undertaken in accordance with Section 11.4.
Open OBC Div. B 11.1.2.1. in the code viewer
OBC Div. B 11.1.1.2. Definitions
(1)In this Part,
Building system means a combination of elements or components that form a complete major division of construction in the design of a building or part of a building, including a structural or framing system, a waterproofing system, a drainage system, an exterior cladding system, a roofing system, a window system, a partition system, a corridor system, a stair system, a fire alarm and detection system, a sprinkler system or a heating, ventilation or air-conditioning system, a foundation system, a standpipe and hose system, a flooring system, a plumbing system, a sewage system or an electrical system.
Open OBC Div. B 11.1.1.2. in the code viewer
OBC Div. A 1.4.1.2.(1) Construction index
Construction index means a level on a scale of 1 to 8 determined in accordance with Table 11.2.1.1.-A of Division B designating the expected performance level of the building structure with respect to the type of construction and fire protection of an existing building, and "C.I." has a corresponding meaning.
Open OBC Div. A 1.4.1.2.(1) in the code viewer
OBC Div. B 11.3.3.2. Extensive Renovation
(1)Where existing interior walls or ceilings or floor assemblies or roof assemblies are substantially removed in an existing building and new interior walls, ceilings, floor assemblies or roof assemblies are installed in the building, structural and fire-resistance elements shall be constructed in compliance with the requirements of the other Parts.
(2)Except as provided in Section 11.5., the proposed construction within an existing suite shall comply with the requirements of Section 3.8. where,
(a)new interior walls or floor assemblies are installed,
(b)the suite has an area greater than 300 m², and
(c)the suite is located in,
(i)a floor area where the existing difference in elevation between the adjacent ground level and the floor level is not more than 200 mm, or
(ii)a normally occupied floor area which is accessible by a passenger type elevator or other platform equipped passenger elevating device from an entrance storey where the existing difference in elevation between the adjacent ground level and the entrance storey level is not more than 200 mm.
(3)Except as provided in Section 11.5., the proposed construction within an existing suite, other than a suite described in Sentence (2) or a suite in a building described in Clause 3.8.1.1.(1)(a), (b), (c) or (d), shall comply with the requirements of Sentences 3.8.1.3.(6), 3.8.2.3.(6), 3.8.3.1.(6), 3.8.3.3.(19), 3.8.3.7.(1), 3.8.3.15.(5) and 3.8.3.16.(4) where new interior walls or floor assemblies are installed. (See Note A-11.3.3.2.(3))
(4)Except as provided in Sentence (5), where existing interior walls or ceilings or floor assemblies or roof assemblies are substantially removed on any storey in an existing building and new interior walls, ceilings, floor assemblies or roof assemblies are installed, the storey shall be sprinklered if,
(a)the storey will contain a Group C major occupancy, and
(b)the building is over 3 storeys in building height.
(5)Sentence (4) does not apply where the building,
(a)conforms to Subclause 3.2.2.50.(1)(a)(ii), and
(b)contains dwelling units having means of egress conforming to Sentence 3.3.4.4.(8).
(6)Where existing interior walls or ceilings or floor assemblies or roof assemblies are substantially removed and new interior walls, ceilings, floor assemblies or roof assemblies are installed in an existing building or part of an existing building that is a retirement home, the following requirements apply:
(a)the retirement home shall be sprinklered,
(b)a voice communication system conforming to Article 3.2.4.23. shall be provided in the building, if Clause 3.2.6.8.(1)(b) or
(c)as applicable, requires that such a voice communication system be provided in the building, and
(c) doors to suites and sleeping rooms not within suites in the retirement home, other than doors leading directly to the exterior, shall be equipped with self-closing devices.
Open OBC Div. B 11.3.3.2. in the code viewer
OBC Div. B 11.4.1.1. Performance Level
(1)The performance level of a building after construction shall not be less than the performance level of the building prior to construction.
(2)For the purposes of Sentence (1), reduction of performance level shall be determined in accordance with Subsection 11.4.2.
(3)Where the proposed construction would reduce the performance level of an existing building, compensating construction shall be required in conformance with Subsection 11.4.3.
(4)For the purpose of this Subsection, where a permit to construct a farm building has been applied for before January 1, 2025, the performance level of the farm building is permitted to be evaluated based on the applicable requirements of Ontario Regulation 332/12 (Building Code) made under the Act, as it read on December 31, 2024.
Open OBC Div. B 11.4.1.1. in the code viewer
OBC Div. B 11.4.3.1. General
(1)Where the performance level of an existing building is reduced under Subsection 11.4.2., compensating construction shall be carried out in accordance with this Subsection.
(2)Except as provided in Sentence (3), compensating construction required under this Subsection applies to the part of the building being altered and shall include,
(a)fire separations, with the required fire-resistance ratings, separating the part being altered from the floor areas immediately above and below and from the immediate adjacent areas, and
(b)access to exits and exits from the building, where the alteration adversely affects the exit system of the building.
(3)Compensating construction required under this Subsection applies to the existing building systems that are adversely affected by the proposed construction.
Open OBC Div. B 11.4.3.1. in the code viewer
OBC Div. B 11.4.3.2. Structural
(1)Where the performance level of an existing building is reduced under Sentence 11.4.2.1.(1),
(a)remedial measures shall be taken to support the proposed loads, or
(b)the portion of the floor affected by the proposed loads shall be restricted to the loading it will support and signs stating the restrictions shall be posted. (See Note A-11.4.3.2.(1))
Open OBC Div. B 11.4.3.2. in the code viewer
OBC Div. B 11.4.3.3. Increase in Occupant Load
(1)Where the performance level of an existing building is reduced under Sentence 11.4.2.2.(1), (2) or (3), the building shall be evaluated, and the early warning and evacuation systems shall be upgraded, in conformance with the applicable requirements of Table 11.4.3.3.
(2)Sentence (1) does not apply in a Group C occupancy where the new total occupant load is,
(a)14 persons or fewer in a boarding, lodging or rooming house, except that where the occupant load is between 10 and 15 persons, an interconnected system of smoke alarms in corridors near stairways is required, or
(b)16 persons or fewer in a building containing residential suites which are dwelling units, except that where the occupant load is between 10 and 17 persons, an interconnected system of smoke alarms in corridors near stairways is required.
(3)Where the performance level of an existing building is reduced under Sentence 11.4.2.2.(1), additional construction shall be required in order that the building or part of the building subject to the increase in occupant load conforms to the requirements of Sentences 2.4.2.1.(1) and 6.3.1.1.(2), Subsection 3.7.4. and Article 9.31.1.1.
Open OBC Div. B 11.4.3.3. in the code viewer
OBC Div. B 11.4.3.4. Change in Major Occupancy
(1)Where the performance level of an existing building is reduced under Clause 11.4.2.3.(1)(a), (b), (c), (d), (e) or (g), additional upgrading shall be required in conformance with Table 11.4.3.4.-A and so that the construction index of the building is increased to at least equal the hazard index of the new major occupancy that the building is to support.
(2)A building or part of the building subject to a change of major occupancy shall conform to the requirements of Articles 2.4.2.3. to 2.4.2.5., Subsection 3.2.6., Sections 3.7., 3.11., 3.12., Sentences 6.3.1.1.(2), and 6.3.2.7.(1) and 9.33.6.13.(7.1), Subsections 9.5.1. and 9.5.3., 9.5.3A. to 9.5.3F. and 9.5.4., Section 9.7., Subsection 9.10.17., Sections 9.31. and 9.32., and Subsections 9.34.1. to 9.34.3. as they apply to the new major occupancy that the building or part of the building is to support.
(3)Where the performance level of an existing building is reduced under Sentence 11.4.2.3.(3), the building shall be evaluated, and the early warning and evacuation systems shall be upgraded, in conformance with the applicable requirements of Table 11.4.3.3.
(4)Where the performance level of an existing building is reduced under Sentence 11.4.2.3.(4), upgrading of the fire separations shall be required in conformance with the applicable requirements of Article 3.1.3.1. and Table 11.4.3.4.-B.
(5)Where the performance level is reduced under Sentence 11.4.2.3.(5), the requirement for the building to be of noncombustible construction or to be constructed in accordance with Article 3.2.2.51. or 3.2.2.60. is satisfied if the building is sprinklered.
(6)Where the performance level is reduced under Sentence 11.4.2.3.(6), the storey subject to the change shall be sprinklered.
(7)Where the performance level of an existing building is reduced under Clause 11.4.2.3.(1)(f), the following requirements apply:
(a)the retirement home shall be sprinklered,
(b)a voice communication system conforming to Article 3.2.4.22. shall be provided in the building, and
(c)doors to suites and sleeping rooms not within suites in the retirement home, other than doors leading directly to the exterior, shall be equipped with self-closing devices.
(8)Where a major occupancy is changed to a Group B, Division 2 major occupancy, heating, ventilating, air conditioning systems shall conform to the requirements of Sentence 6.2.1.1.(1).
(9)Where a major occupancy is changed to a Group B, Division 3 major occupancy, ventilation, air circulation, and filtration systems shall conform to the requirements of Sentence 6.2.1.1.(1).
Open OBC Div. B 11.4.3.4. in the code viewer
OBC Div. B 11.4.3.7. Extension of Buildings of Combustible Construction
(1)Where the performance level of an existing building is reduced under Article 11.4.2.6., the building shall be sprinklered.
Open OBC Div. B 11.4.3.7. in the code viewer
OBC Div. A 1.4.1.2.(1) Compliance alternative
Compliance alternative means a substitute for a requirement in another Part of Division B that is listed in Part 10 or 11 of Division B, and "C.A." has a corresponding meaning.
Open OBC Div. A 1.4.1.2.(1) in the code viewer
OBC Div. B 11.5.1.1. Compliance Alternatives
(1)A compliance alternative shown in Table 11.5.1.1.-A, 11.5.1.1.-B, 11.5.1.1.-C, 11.5.1.1.-D/E or 11.5.1.1.-F may be substituted for a requirement contained in Part 3, 4, 6 or 8 where the chief building official is satisfied that compliance with the requirement is impracticable because,
(a)of structural or construction difficulties, or
(b)it is detrimental to the preservation of a heritage building.
(2)A compliance alternative shown in Table 11.5.1.1.-A, 11.5.1.1.-B, 11.5.1.1.-C, 11.5.1.1.-D/E or 11.5.1.1.-F may be substituted for a requirement contained in Part 9 or 12 without satisfying the chief building official that compliance with the requirement is impracticable.
Open OBC Div. B 11.5.1.1. in the code viewer