PRESCRIPTIVE COMPLIANCE METHOD

Transcription

1 CHAPTER PRESCRIPTIVE COMPLIANCE METHOD 3 SECTION 301 GENERAL Building materials. Building materials shall comply with the requirements of this section Existing materials. Materials already in use in a building in compliance with requirements or approvals in effect at the time of their erection or installation shall be permitted to remain in use unless determined by the code official to be dangerous to life, health or safety. Where such conditions are determined to be dangerous to life, health or safety, they shall be mitigated or made safe New and replacement materials. Except as otherwise required or permitted by this code, materials permitted by the applicable code for new construction shall be used. Like materials shall be permitted for repairs and alterations, provided no hazard to life, health or property is created. Hazardous materials shall not be used where the code for new construction would not permit their use in buildings of similar occupancy, purpose and location. The owner of a tenant space within an office building is proposing to alter her work space, which would include a reconfiguration of a portion of the egress corridor that serves other tenants on the same floor. The corridor is not rated, and there is no sprinkler system within the building. The architect is proposing to use the prescriptive compliance method of Chapter 3 of the IEBC. The construction plans do not indicate that the new construction would comply with the IBC for rating the new walls of the corridor. The applicant is citing Section , which requires only like materials of the existing corridor for the alterations. The local code official is citing the definition of Alteration in Chapter 2 of the IEBC, which indicates that alterations are classified as Level 1, 2, or 3, and since this would be considered a Level 2 alteration, Section would require the new construction comply with the IBC and the corridor alteration be a rated assembly. Which interpretation is correct? The requirements of Chapter 7 cannot be imposed on a project where the design profes- sional or owner chooses to use the prescriptive compliance method of Chapter 3. However, the code official in this case would be correct in insisting that the reconfigured corridor meet the construction requirements of the IBC. The intent of Section is to ensure that if materials involved in the construction of the existing corridor were being replaced, the new materials used for replacement could be like materials. Any newly reconfigured walls must comply with the IBC. See Figure 3-1. [3-1] EXISTING NON-RATED CORRIDOR SECTION 302 PROPOSED RATED CORRIDOR IN COMPLIANCE w/bc NEW CONSTRUCTION REQUIREMENT FIGURE 3-1 ADDITIONS General. Additions to any building or structure shall comply with the requirements of the International Building Code for new construction. Alterations to the existing building or structure shall be made to ensure that the existing building or structure together with the addition are no less conforming to the provisions of the International Building Code than the existing building or structure was prior to the addition. An existing build- 13

2 ing together with its additions shall comply with the height and area provisions of Chapter 5 of the International Building Code. The owners of an existing clubhouse to a private country club are proposing to build an addition to the existing building. The addition is intended to be a multipurpose room for banquets, dances, and meetings. The building is a mixed-use building with a combination of Group B, M, and A-2 occupancies. Further, there is no separation between the respective occupancies, and they currently exceed the height and area limitations as calculated under the provisions of the IBC. Would Section allow the addition to be built if a fire wall is constructed in accordance with the IBC between the addition and the existing building? Could the owners build a fire barrier instead of a fire wall? A fire wall that meets all of the provisions of the IBC, i.e., hourly rating, continuity, and structural independence, and does not create any additional non-conformity for the existing building could be constructed to create two separate buildings, thus allowing the addition to be built. The construction of the addition must be built in compliance with the IBC and all other referenced codes. A fire barrier is not considered an equivalent to a fire wall and therefore would not be an acceptable alternative that would allow additional height and area to the existing building. [3-2] Would an alteration of an attic into living space be considered an addition under Section 302.1, therefore having to comply with the IBC in total for the new space? Yes. Typical attic areas do not have flooring and are not considered to have floor space. The renovation of the area into habitable floor space increases the total current floor area and height of the building and therefore would be identified as an addition. [3-3] A basement is being converted from a storage area into a finished recreational room in an office building. Would this be considered an addition of floor area and need to comply with the IBC for height and area as well as the IECC for new construction? This would not be considered an addition since typically the area of a basement is initially calculated into the height and area of a building when it is constructed. However, the change from a storage area to a recreational room would be considered a change of occupancy with alterations. This would require that the new occupancy and any alterations comply with both Sections and of the prescriptive compliance method or Sections 902 through 912 of the work area method for the new use. It must also comply with the applicable alterations chapter. [3-4] If the prescriptive compliance method for an addition is applied, would the addition of a non-occupiable appendage such as an elevator or exit stair shaft be considered additional area of the building to be included in the overall area calculation in accordance with Chapter 5 of the IBC? Yes. The definition of area as discussed in Section 502 of the IBC does not give any exceptions for these types of additions. Additions regulated by the work area method would be permitted according to the exception to Section of the IEBC. See Figure 3-5. [3-5] ALTAR AREA 2ND LEVEL SANCTUARY INCREASE IN AREA FIGURE 3-5 PROPOSED NEW ELEVATOR [B] SECTION 303 ALTERATIONS General. Except as provided by Section or this section, alterations to any building or structure shall comply with the requirements of the International Building Code for new construction. Alterations shall be such that the existing building or structure is no less con- 14

3 forming to the provisions of the International Building Code than the existing building or structure was prior to the alteration. Exceptions: 1. An existing stairway shall not be required to comply with the requirements of Section 1009 of the International Building Code where the existing space and construction does not allow a reduction in pitch or slope. 2. Handrails otherwise required to comply with Section of the International Building Code shall not be required to comply with the requirements of Section of the International Building Code regarding full extension of the handrails where such extensions would be hazardous due to plan configuration. We are replacing the entire HVAC system in a building. When evaluating which method to use from the IEBC, i.e., the prescriptive compliance method (Section 303) or the work area compliance method (Section 709), we believe there is no real advantage to either method, since both would require all work to comply with the International Mechanical Code. Is this a correct assessment? The basic answer is yes. Any alterations can place additional loads or different demands on an existing system, which could require changes to the entire system when the builder is using Section 303. The main scoping language of this section states that any alterations cannot make the existing system less compliant with the code. Section 709 allows for alternative minimum requirements for ventilation under Section However, it is doubtful if this would reduce the amount of engineering work that would need to be executed. [3-6] A building owner is replacing a means-ofegress stairway. The stairway is enclosed by concrete masonry units. There are several components of the stairway that do not comply with Chapter 10 of the IBC, i.e., riser height and tread depth, dimensional uniformity of the risers, handrail heights, graspability of the handrail, and nosing. Is it the intent of Exception 1 to Section of the IEBC to allow the stairway to be reconstructed exactly as it was previously, including the noted deficiencies with respect to the IBC? The primary intent of Exception 1 to Section is to not impose the requirements of Section 1009 of the IBC. To do so would, in effect, reduce the steepness of a stair that may not fit within the enclosure walls. Further, Exception 2 of Section grants relief related to the extension of the handrails where they would be deemed hazardous by the code official due to the plan configuration. Other safety requirements related to handrails and dimensional uniformity are required to meet the provisions of the IBC. [3-7] Means of egress capacity factors. Alterations to any existing building or structure shall not be subject to the egress width factors in Section of the International Building Code for new construction in determining the minimum egress widths or the minimum number of exits in an existing building or structure. The minimum egress widths for the components of the means of egress shall be based on the means of egress width factors in the building code under which the building was constructed, and shall be considered as complying means of egress for any alteration if, in the opinion of the code official, they do not constitute a distinct hazard to life. The owner of a six-story office building is initiating alterations on the fourth floor. The work will include reconfiguring the entire common corridor system and tenant layout of the floor. The existing corridors and stairways do not meet the required egress capacity based on occupant load calculations of Section 1005 of the International Building Code or the model code that was in place at the time the building was constructed. Would Section of the IEBC exempt the new corridors or the existing stairways from compliance with Section 1005 of the IBC? The altered corridors must comply with Section of the IEBC, which requires the construction to comply with the IBC for new construction. Section is intended primarily to apply to existing corridors, stairways, and similar elements that are to remain but will be used to carry a modified occupant load. The egress width factors of the IBC would not be imposed if the means of egress elements are compliant with the code under which the building was built. If the stairways were not compliant with the adopted code at the time of construction, technically the code official could ask for them to be brought into compliance. However the code official would need to evaluate the existing state of 15

4 the stairways and make a determination as to the level of safety being provided before initiating any enforcement action. It would be legally difficult to mandate an upgrade to code compliance if the stairs are not considered unsafe. [3-8] SECTION 305 FIRE ESCAPES Where permitted. Fire escapes shall be permitted only as provided for in Sections through New buildings. Fire escapes shall not constitute any part of the required means of egress in new buildings Existing fire escapes. Existing fire escapes shall continue to be accepted as a component in the means of egress in existing buildings only New fire escapes. New fire escapes for existing buildings shall be permitted only where exterior stairs cannot be utilized due to lot lines limiting stair size or due to the sidewalks, alleys or roads at grade level. New fire escapes shall not incorporate ladders or access by windows Limitations. Fire escapes shall comply with this section and shall not constitute more than 50 percent of the required number of exits nor more than 50 percent of the required exit capacity. The owner of a Group R-2 occupancy apartment building is renovating two floors of a five-story building. The alterations are intended to reduce the number of rental units and increase the size of other dwelling units. There is one enclosed stairway. The other means of egress is an existing fire escape. The access to the fire escape has been through windows. Further, prior to the alterations, some occupants would have to traverse through another dwelling unit to gain access to the fire escape. Due to the extent of the alterations, would access to the fire escape be required from a common area for all occupants through a full-size access door? No. Section would allow the existing fire escape to be used for the altered dwelling units in the same manner as the pre-existing dwelling units. Further, Section would allow egress widths under which the building was originally built. [3-9] Location. Where located on the front of the building and where projecting beyond the building line, the lowest landing shall not be less than 7 feet (2134 mm) or more than 12 feet (3658 mm) above grade, and shall be equipped with a counterbalanced stairway to the street. In alleyways and thoroughfares less than 30 feet (9144 mm) wide, the clearance under the lowest landing shall not be less than 12 feet (3658 mm) Construction. The fire escape shall be designed to support a live load of 100 pounds per square foot (4788 Pa) and shall be constructed of steel or other approved noncombustible materials. Fire escapes constructed of wood not less than nominal 2 inches (51 mm) thick are permitted on buildings of Type V construction. Walkways and railings located over or supported by combustible roofs in buildings of Type III and IV construction are permitted to be of wood not less than nominal 2 inches (51 mm) thick Dimensions. Stairs shall be at least 22 inches (559 mm) wide with risers not more than, and treads not less than, 8 inches (203 mm) and landings at the foot of stairs not less than 40 inches (1016 mm) wide by 36 inches (914 mm) long, located not more than 8 inches (203 mm) below the door Opening protectives. Doors and windows along the fire escape shall be protected with 3 / 4 -hour opening protectives. The owners of a four-story hotel are upgrading the entire building by reconfiguring walls to provide more hotel rooms, adding new paint, and installing new carpeting and a new fire alarm system. The existing building is 85 years old and has only one enclosed stairway. The other means of exiting within the building is an existing fire escape. There are several windows along the path of the fire escape. Would these openings be required to have some level of fire protection so that fire would not impede the exiting of occupants down the fire escape? Yes. Section requires all doors and windows along the fire escape to have minimum protection equal to a ¾-hour fire-protection rating. [3-10] Are the provisions of Sections through intended to be applied to existing fire escapes? 16

5 Not all of these sections apply to existing fire escapes. Section allows existing fire escapes to be used as means of egress without any change, provided the fire escape is in good condition and is structurally sound. Sections through apply to new fire escapes being installed on existing buildings. Section 305.5, related to the protection of openings along the fire escape, applies to all fire escapes, both new and existing, when alterations, repairs, or additions are being initiated within a building, since this section does not apply directly to the construction of the fire escape but only to openings. [3-11] SECTION 307 CHANGE OF OCCUPANCY [B] Conformance. No change shall be made in the use or occupancy of any building that would place the building in a different division of the same group of occupancy or in a different group of occupancies, unless such building is made to comply with the requirements of the International Building Code for such division or group of occupancy. Subject to the approval of the building official, the use or occupancy of existing buildings shall be permitted to be changed and the building is allowed to be occupied for purposes in other groups without conforming to all the requirements of this code for those groups, provided the new or proposed use is less hazardous, based on life and fire risk, than the existing use Change of occupancy. Existing buildings that undergo a change of group or occupancy shall comply with this section Partial change in occupancy. Where a portion of the building is changed to a new occupancy classification, any alterations shall comply with Sections 310.6, and Complete change of occupancy. Where an entire building undergoes a change of occupancy, it shall comply with Section and shall have all of the following accessible features: 1. At least one accessible building entrance. 2. At least one accessible route from an accessible building entrance to primary function areas. 3. Signage complying with Section 1110 of the International Building Code. 4. Accessible parking, where parking is being provided. 5. At least one accessible passenger loading zone, when loading zones are provided. 6. At least one accessible route connecting accessible parking and accessible passenger loading zones to an accessible entrance. Where it is technically infeasible to comply with the new construction standards for any of these requirements for a change of group or occupancy, the above items shall conform to the requirements to the maximum extent technically feasible. Would a change to a portion of a restaurant into a night club be considered a change of occupancy if an architect chooses to use the prescriptive method as outlined in Chapter 3, specifically related to Section on accessibility? Chapter 3 does not differentiate between a change of occupancy and a change of occupancy classification but identifies changes between divisions and groups of occupancy. Since both occupancies are considered Group A-2 occupancies, the change does not place the building in a different division of the same group nor in a different group of occupancies. This would not be considered a change in occupancy according to Section 307. [3-12] [EC] Energy. Buildings undergoing a change in occupancy that would result in an increase in demand for either fossil fuel or electrical energy shall comply with the International Energy Conservation Code Electrical. It shall be unlawful to make a change in the occupancy of a structure that will subject the structure to the special provisions of the International Building Code related to electrical installations applicable to the new occupancy without approval. The code official shall certify that the structure meets the intent of the provisions of law governing building construction for the proposed new occupancy and that such change of occupancy does not result in any hazard to the public health, safety or welfare. [FG] Fuel gas. It shall be unlawful to make a change in the occupancy of a structure that will subject the structure to the special provisions of the International Fuel Gas Code applicable to the new occupancy without approval. The code official shall certify that the structure meets the intent of the provisions of law governing building construction for the proposed new occupancy and that such change of occupancy does not result in any hazard to the public health, safety or welfare. 17