The issue of fire separation distances
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If there are no combustible materials on a house’s balcony, where should the fire separation distance be measured from? If the stairwell of a house is located outside the wall, where does the fire separation distance begin?
I don’t understand what the original poster is trying to say. Building codes classify fire separation distances according to factories, warehouses, liquid storage areas, gas storage tanks, residential buildings, etc.; I’m not clear about what question the poster wants to ask! 5.2 Fire separation distances for civil buildings 5.2.1 The fire separation distance between civil buildings shall not be less than the values specified in Table 5.2.1; the fire separation distance from other buildings shall be determined in accordance with the relevant provisions in Chapters 3 and 4 of this code. Table 5.2.1 Fire separation distances between civil buildings (m)
Fire resistance rating: Grade I & II, Grade III, Grade IV
Grade I & II: 6.0, 7.0, 9.0
Grade III: 7.0, 8.0, 10.0
Grade IV: 9.0, 10.0, 12.0
Note: 1. If the adjacent higher exterior wall of two buildings serves as a fire wall, or if the exterior wall within a range of 15 meters above the roof of the adjacent lower building with a Grade I or II fire resistance rating also functions as a fire wall and has no doors or windows, then there is no requirement regarding the fire separation distance ； 2 For two adjacent buildings, if the fire resistance rating of the lower building is not lower than Grade 2, there are no skylights on its roof, the fire resistance duration of the roof’s load-bearing components and roof panels is not less than 1.00 hour, and the adjacent lower exterior wall serves as a fire wall, then the fire separation distance between them should be no less than 3.5 m ； 3 For two adjacent buildings, if the fire resistance rating of the lower building is not lower than grade II, and fire-resistant doors and windows of class A are installed at the openings in the outer wall of the higher adjacent building, or a fire separation water curtain in accordance with the current **standard \"Code for Design of Automatic Sprinkler Systems\" GB50084, or a fire shutter as specified in Article 7.5.3 of this standard is installed, then the fire separation distance between them should not be less than 3.5 m ； 4 For two adjacent buildings, when the adjacent exterior walls are non-combustible and there are no exposed combustible eaves, and the door and window openings on each exterior wall that lack fire protection measures are not positioned directly opposite each other, with their combined area being less than or equal to 5% of the area of that exterior wall, the required fire separation distance can be reduced by 25% in accordance with the provisions of this table ； 5 For existing buildings with a fire resistance rating lower than grade 4, their fire resistance rating can be determined as grade 4 ； For buildings with wooden columns as load-bearing elements and non-combustible materials used for walls, the fire resistance rating shall be determined as Grade 4 ； 6 The fire separation distance shall be calculated based on the closest distance between the outer walls of adjacent buildings. When there are protruding combustible components on the outer walls, the measurement shall be taken from the outer edge of such protrusions. 5.2.2 For civil buildings and separately constructed terminal substations, as well as coal-fired boiler rooms in which the evaporation capacity of a single steam boiler is less than or equal to 4 t/h or the rated heat power of a single hot water boiler is less than or equal to 2.8 MW, the fire separation distances may be determined in accordance with the provisions of Article 5.2.1 of these specifications. For civil buildings and other separately constructed substation buildings, fuel or gas boiler rooms, as well as coal-fired boiler rooms with an evaporation rate or rated heat output exceeding the specified values, the fire separation distances shall be in accordance with the provisions set out in Article 3.4.1 of these codes regarding outdoor substations and distribution stations, as well as Class D industrial buildings. The fire protection distance between pad-mounted transformers rated at 10 kV or below and buildings shall not be less than 3.0 m. 5.2.3 For multiple multi-story residential or office buildings with fire resistance ratings of grade I or II, when the total floor area of these buildings is less than or equal to 2500 m2, they may be arranged in groups; however, the distance between buildings within a group should not be less than 4.0 m. The fire separation distance between groups or between a group and adjacent buildings shall not be less than the requirements specified in Article 5.2.1 of this Code.
Fire resistance rating: Grade I & II, Grade III, Grade IV
Grade I & II: 6.0, 7.0, 9.0
Grade III: 7.0, 8.0, 10.0
Grade IV: 9.0, 10.0, 12.0
Note: 1. If the adjacent higher exterior wall of two buildings serves as a fire wall, or if the exterior wall within a range of 15 meters above the roof of the adjacent lower building with a Grade I or II fire resistance rating also functions as a fire wall and has no doors or windows, then there is no requirement regarding the fire separation distance ； 2 For two adjacent buildings, if the fire resistance rating of the lower building is not lower than Grade 2, there are no skylights on its roof, the fire resistance duration of the roof’s load-bearing components and roof panels is not less than 1.00 hour, and the adjacent lower exterior wall serves as a fire wall, then the fire separation distance between them should be no less than 3.5 m ； 3 For two adjacent buildings, if the fire resistance rating of the lower building is not lower than grade II, and fire-resistant doors and windows of class A are installed at the openings in the outer wall of the higher adjacent building, or a fire separation water curtain in accordance with the current **standard \"Code for Design of Automatic Sprinkler Systems\" GB50084, or a fire shutter as specified in Article 7.5.3 of this standard is installed, then the fire separation distance between them should not be less than 3.5 m ； 4 For two adjacent buildings, when the adjacent exterior walls are non-combustible and there are no exposed combustible eaves, and the door and window openings on each exterior wall that lack fire protection measures are not positioned directly opposite each other, with their combined area being less than or equal to 5% of the area of that exterior wall, the required fire separation distance can be reduced by 25% in accordance with the provisions of this table ； 5 For existing buildings with a fire resistance rating lower than grade 4, their fire resistance rating can be determined as grade 4 ； For buildings with wooden columns as load-bearing elements and non-combustible materials used for walls, the fire resistance rating shall be determined as Grade 4 ； 6 The fire separation distance shall be calculated based on the closest distance between the outer walls of adjacent buildings. When there are protruding combustible components on the outer walls, the measurement shall be taken from the outer edge of such protrusions. 5.2.2 For civil buildings and separately constructed terminal substations, as well as coal-fired boiler rooms in which the evaporation capacity of a single steam boiler is less than or equal to 4 t/h or the rated heat power of a single hot water boiler is less than or equal to 2.8 MW, the fire separation distances may be determined in accordance with the provisions of Article 5.2.1 of these specifications. For civil buildings and other separately constructed substation buildings, fuel or gas boiler rooms, as well as coal-fired boiler rooms with an evaporation rate or rated heat output exceeding the specified values, the fire separation distances shall be in accordance with the provisions set out in Article 3.4.1 of these codes regarding outdoor substations and distribution stations, as well as Class D industrial buildings. The fire protection distance between pad-mounted transformers rated at 10 kV or below and buildings shall not be less than 3.0 m. 5.2.3 For multiple multi-story residential or office buildings with fire resistance ratings of grade I or II, when the total floor area of these buildings is less than or equal to 2500 m2, they may be arranged in groups; however, the distance between buildings within a group should not be less than 4.0 m. The fire separation distance between groups or between a group and adjacent buildings shall not be less than the requirements specified in Article 5.2.1 of this Code.
If there are protruding balconies (without combustible materials), where does the fire separation distance begin?
In the case of a protruding balcony (without flammable materials), the fire separation distance is measured from the center axis of the wall
In the case of a protruding balcony (without flammable materials), the fire separation distance is measured from the center axis of the wall
I remember that the old standard GBJ16-87 contained a clear explanation; it doesn’t seem to mention anything in the 2006 version