GENERAL BUILDING HEIGHTS AND AREAS

Transcription

1 CHPTER GENERL BUILDING HEIGHT ND RE ECTION 0 GENERL 0. cope. The provisions of this chapter control the height and area of structures hereafter erected and additions to existing structures. [F] 0. Premises identification. pproved numbers or addresses shall be provided for new buildings in such a position as to be clearly visible and legible from the street or roadway fronting the property. Letters or numbers shall be a minimum inches (76 mm) in height and stroke of minimum 0. inch (.7 mm) of a contrasting color to the background itself. INDUTRIL EQUIPMENT PLTFORM. n unoccupied, elevated platform in an industrial occupancy used exclusively for mechanical systems or industrial process equipment, including the associated elevated walkways, stairs and ladders necessary to access the platform (see ection 0.). MEZZNINE. n intermediate level or levels between the floor and ceiling of any story with an aggregate floor area of not more than one-third of the area of the room or space in which the level or levels are located (see ection 0). TORY. That portion of a building included between the upper surface of a floor and the upper surface of the floor or roof next above (also see Basement and Mezzanine ). ECTION 0 DEFINITION 0. Definitions. The following words and terms shall, for the purposes of this chapter and as used elsewhere in this code, have the meanings shown herein. RE, BUILDING. The area included within surrounding exterior walls (or exterior walls and fire walls) exclusive of vent shafts and courts. reas of the building not provided with surrounding walls shall be included in the building area if such areas are included within the horizontal projection of the roof or floor above. BEMENT. That portion of a building that is partly or completely below grade plane (ee tory above grade plane in ection 0). basement shall be considered as a story above grade plane where the finished surface of the floor above the basement is:. More than 6 feet (89 mm) above grade plane;. More than 6 feet (89 mm) above the finished ground level for more than 0 percent of the total building perimeter; or. More than feet (68 mm) above the finished ground level at any point. GRDE PLNE. reference plane representing the average of finished ground level adjoining the building at exterior walls. Where the finished ground level slopes away from the exterior walls, the reference plane shall be established by the lowest points within the area between the building and the lot line or, where the lot line is more than 6 feet (89 mm) from the building, between the building and a point 6 feet (89 mm) from the building. HEIGHT, BUILDING. The vertical distance from grade plane to the average height of the highest roof surface. HEIGHT, TORY. The vertical distance from top to top of two successive finished floor surfaces; and, for the topmost story, from the top of the floor finish to the top of the ceiling joists or, where there is not a ceiling, to the top of the roof rafters. ECTION 0 GENERL HEIGHT ND RE LIMITTION 0. General. The height and area for buildings of different construction types shall be governed by the intended use of the building and shall not exceed the limits in Table 0 except as modified hereafter. Each part of a building included within the exterior walls or the exterior walls and fire walls where provided shall be permitted to be a separate building. 0.. Basements. Basements need not be included in the total allowable area provided they do not exceed the area permitted for a one-story building. 0.. pecial industrial occupancies. Buildings and structures designed to house low-hazard industrial processes that require large areas and unusual heights to accommodate craneways or special machinery and equipment including, among others, rolling mills; structural metal fabrication shops and foundries; or the production and distribution of electric, gas or steam power, shall be exempt from the height and area limitations of Table Buildings on same lot. Two or more buildings on the same lot shall be regulated as separate buildings or shall be considered as portions of one building if the height of each building and the aggregate area of buildings are within the limitations of Table 0 as modified by ections 0 and 06. The provisions of this code applicable to the aggregate building shall be applicable to each building. 0.. Type I construction. Buildings of Type I construction permitted to be of unlimited tabular heights and areas are not subject to the special requirements that allow unlimited area buildings in ection 07 or unlimited height in ections 0.. and 0. or increased height and areas for other types of construction. 0. Party walls. ny wall located on a lot line between adjacent buildings, which is used or adapted for joint service between the two buildings, shall be constructed as a fire wall in accordance with ection 70, without openings and shall create separate buildings. 00 INTERNTIONL BUILDING CODE 7

2 GENERL BUILDING HEIGHT ND RE TBLE 0 LLOWBLE HEIGHT ND BUILDING RE Height limitations shown as stories and feet above grade plane. rea limitations as determined by the definition of rea, building, per floor. Hgt(feet) TYPE OF CONTRUCTION TYPE I TYPE II TYPE III TYPE IV TYPE V B B B HT B GROUP B E F- F- H- H- H- H- H- I- I- I- I- M R- Hgt() R- a R- a R- - - b, c U c,000,000 6,00 6, , ,000 60,00 8,000 7,00 For I: foot = 0.8 mm, square foot = m. = Unlimited, = Not permitted. a. s applicable in ection 0.. b. For open parking structures, see ection 06.. c. For private garages, see ection 06..,00,00,00,00 7,00 6,00,000 7,00,000,000 6,00 7,00 7,00,000,000 6,00,00,000,000,000 6,000 8,00 9,00 9,00 9,00,000,00,00,000,000 7,00,000 0,000,000 0,000,000,00 6,000 6,000 6,000 7,00 6,000 8,00,000,000,000,000 8,00,00 8,00 9,00 9,00 7,00 8,00 8,00 6,00,000 0,00,00 8,00,000,000,000 6,000,000 8,00 9,00 9,00 9,00,00,000 8,000,000 7,00 0,000 7,00,000,00 6,000 6,000 6,000 7,00 6,000 8,00,000,000,000,000 6,000,00,00 0,00 0,00 0,00,00 6,000 6,000 8,000,000,000,00 0,00 0,00 0,00 0,00,00 8,00 8,000,00,00,00,00 8,000 8,00,000,000 7,00 7,00 0,000 8,000 8,000 0,00 9,00 7,00 8,00,000,000,000,000,000,000,00 6,000 6,000 6,000 9,00 8,00,000,000,000 6,00,00,000,00, INTERNTIONL BUILDING CODE

3 GENERL BUILDING HEIGHT ND RE ECTION 0 HEIGHT MODIFICTION 0. General. The heights permitted by Table 0 shall only be increased in accordance with this section. Exception: The height of one-story aircraft hangars, aircraft paint hangars and buildings used for the manufacturing of aircraft shall not be limited if the building is provided with an automatic fire-extinguishing system in accordance with Chapter 9 and is entirely surrounded by public ways or yards not less in width than one and one-half times the height of the building. 0. utomatic sprinkler system increase. Where a building is equipped throughout with an approved automatic sprinkler system in accordance with ection 90..., the value specified in Table 0 for maximum height is increased by 0 feet (6096 mm) and the maximum number of stories is increased by one story. These increases are permitted in addition to the area increase in accordance with ections 06. and 06.. For Group R buildings equipped throughout with an approved automatic sprinkler system in accordance with ection 90..., the value specified in Table 0 for maximum height is increased by 0 feet (6096 mm) and the maximum number of stories is increased by one story, but shall not exceed four stories or 60 feet (8 88 mm), respectively.. Group I- of Type IIB, III, IV or V construction.. Group H-, H-, H- or H-.. Fire-resistance rating substitution in accordance with Table 60, Note d. 0. Roof structures. Towers, spires, steeples and other roof structures shall be constructed of materials consistent with the required type of construction of the building except where other construction is permitted by ection uch structures shall not be used for habitation or storage. The structures shall be unlimited in height if of noncombustible materials and shall not extend more than 0 feet (6096 mm) above the allowable height if of combustible materials (see Chapter for additional requirements). ECTION 0 MEZZNINE 0. General. mezzanine or mezzanines in compliance with this section shall be considered a portion of the floor below. uch mezzanines shall not contribute to either the building area or number of stories as regulated by ection 0.. The area of the mezzanine shall be included in determining the fire area defined in ection 70. The clear height above and below the mezzanine floor construction shall not be less than 7 feet ( mm). 0. rea limitation. The aggregate area of a mezzanine or mezzanines within a room shall not exceed one-third of the area of that room or space in which they are located. The enclosed portions of rooms shall not be included in a determination of the size of the room in which the mezzanine is located. In determining the allowable mezzanine area, the area of the mezzanine shall not be included in the area of the room. Exception: The aggregate area of mezzanines in buildings and structures of Type I or II construction for special industrial occupancies in accordance with ection 0.. shall not exceed two-thirds of the area of the room. 0. Egress. Each occupant of a mezzanine shall have access to at least two independent means of egress where the common path of egress travel exceeds the limitations of ection 0.. Where a stairway provides a means of exit access from a mezzanine, the maximum travel distance includes the distance traveled on the stairway measured in the plane of the tread nosing.. single means of egress shall be permitted in accordance with ection 0... ccessible means of egress shall be provided in accordance with ection Openness. mezzanine shall be open and unobstructed to the room in which such mezzanine is located except for walls not more than inches (067 mm) high, columns and posts.. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the occupant load of the aggregate area of the enclosed space does not exceed 0.. mezzanine having two or more means of egress is not required to be open to the room in which the mezzanine is located, if at least one of the means of egress provides direct access to an exit from the mezzanine level.. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the aggregate floor area of the enclosed space does not exceed 0 percent of the mezzanine area.. In industrial facilities, mezzanines used for control equipment are permitted to be glazed on all sides.. In Group F occupancies of unlimited area, meeting the requirements of ection 07. or 07., mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that an approved fire alarm system is installed throughout the entire building or structure and notification appliances are installed throughout the mezzanines in accordance with the provisions of NFP 7. In addition, the fire alarm system shall be initiated by automatic sprinkler water flow. 0. Industrial equipment platforms. Industrial equipment platforms in buildings shall not be considered as a portion of the floor below. uch equipment platforms shall not contribute to either the building area or the number of stories as regulated by ection 0.. The area of the industrial equipment platform shall not be included in determining the fire area. Industrial equipment platforms shall not be a part of any mezzanine, and such platforms and the walkways, stairs and ladders providing access to an equipment platform shall not serve as a part of the means of egress from the building. 00 OREGON TRUCTURL PECILTY CODE 7

4 GENERL BUILDING HEIGHT ND RE 0.. rea limitations. The aggregate area of all industrial equipment platforms within a room shall not exceed two-thirds of the area of the room in which they occur. Where an equipment platform is located in the same room as a mezzanine, the area of the mezzanine shall be determined by ection 0., and the combined aggregate area of the equipment platforms and mezzanines shall not exceed two-thirds of the room in which they occur. 0.. Fire suppression. Where located in a building that is required to be protected by an automatic sprinkler system, industrial equipment platforms shall be fully protected by sprinklers above and below the platform, where required by the standards referenced in ection Guards. Equipment platforms shall have guards where required by ection 0.. ECTION 06 RE MODIFICTION 06. General. The areas limited by Table 0 shall be permitted to be increased due to frontage (I f ) and automatic sprinkler system protection (I s ) in accordance with the following: I t f I t s a = t (Equation -) where: a = llowable area per floor (square feet). t = Tabular area per floor in accordance with Table 0 (square feet). I f = rea increase due to frontage (percent) as calculated in accordance with ection 06.. I s = rea increase due to sprinkler protection (percent) as calculated in accordance with ection Basements. single basement need not be included in the total allowable area provided such basement does not exceed the area permitted for a one-story building. 06. Frontage increase. Every building shall adjoin or have access to a public way to receive an area increase for frontage. Where a building has more than percent of its perimeter on a public way or open space having a minimum width of 0 feet (6096 mm), the frontage increase shall be determined in accordance with the following: F W I f = 00 0 P 0 (Equation -) where: I f = rea increase due to frontage. F = Building perimeter which fronts on a public way or open space having 0 feet (6096 mm) open minimum width (feet). P = Perimeter of entire building (feet). W = Width of public way or open space (feet) in accordance with ection Width limits. W must be at least 0 feet (6096 mm) and the quantity W divided by 0 shall not exceed.0. Where the value of W varies along the perimeter of the 76R building, the calculation performed in accordance with Equation - shall be based on the weighted average of each portion of exterior wall and open space where the value of W is between 0 and 0 feet (6096 and 9 mm). Exception: The quantity W divided by 0 shall be permitted to not exceed.0 when all of the following conditions exist:. The building is permitted to be unlimited in area by ection 07; and. The only provision preventing unlimited area is compliance with the 60-foot (8 88 mm) public way or yard requirement, as applicable Open space limits. uch open space shall be either on the same lot or dedicated for public use and shall be accessed from a street or approved fire lane. 06. utomatic sprinkler system increase. Where a building is equipped throughout with an approved automatic sprinkler system in accordance with ection 90..., the area limitation in Table 0 is permitted to be increased by an additional 00 percent (I s = 00 percent) for multistory buildings and an additional 00 percent (I s = 00 percent) for single-story buildings. These increases are permitted in addition to the height and story increases in accordance with ection 0... Buildings with an occupancy in Group H-, H- or H-.. Fire-resistance rating substitution in accordance with Table 60, Note d.. The allowable area for Group I- occupancies may be doubled in buildings of any height. 06. rea determination. The maximum area of a building with more than one story shall be determined by multiplying the allowable area of the first floor ( a ), as determined in ection 06., by the number of stories as listed below.. For two-story buildings, multiply by ;. For three-story or higher buildings, multiply by ; and,. No story shall exceed the allowable area per floor ( a ), as determined in ection 06. for the occupancies on that floor.. Unlimited area buildings in accordance with ection 07.. The maximum area of a building equipped throughout with an automatic sprinkler system in accordance with ection shall be determined by multiplying the allowable area per floor ( a ), as determined in ection 06. by the number of stories. ECTION 07 UNLIMITED RE BUILDING 07. Nonsprinklered, one story. The area of a one-story, Group F- or - building shall not be limited when the building is surrounded and adjoined by public ways or yards not less than 60 feet (8 88 mm) in width. 07. prinklered, one story. The area of a one-story, Group B, F, M or building or a one-story Group - building of other 00 OREGON TRUCTURL PECILTY CODE

5 GENERL BUILDING HEIGHT ND RE than Type V construction shall not be lim ited when the building is pro vided with an automatic sprinkler system through out in ac cor dance with ection 90..., and is surrounded and ad - joined by public ways or yards not less than 60 feet (8 88 mm) in width. Ex cep tions:. Buildings and structures of Type I and II construction for rack storage fa cil i ties which do not have ac cess by the public shall not be limited in height provided that such build ings conform to the re quire ments of ec - tion 07. and NFP C.. The automatic sprinkler system shall not be re quired in areas occupied for in door participant sports, such as ten nis, skating, swim ming and eques trian activities, in occupancies in Group -, provided that:.. Exit doors directly to the outside are pro vided for oc cu pants of the participant sports areas, and.. The build ing is equipped with a fire alarm sys - tem with manual fire alarm boxes installed in ac cor dance with ection Two story. The area of a two-story, Group B, F, M or building shall not be lim ited when the building is provided with an automatic sprinkler system in accordance with ec tion through out, and is surrounded and ad joined by public ways or yards not less than 60 feet (8 88 mm) in width. 07. Re duced open space. The per ma nent open space of 60 feet (8 88 mm) re quired in ec tions 07., 07. and 07. shall be permitted to be reduced to not less than 0 feet ( 9 mm) pro vided the following re quire ments are met:. The reduced open space shall not be allowed for more than 7 per cent of the per im e ter of the building.. The ex te rior wall facing the reduced open space shall have a min i mum fire-resistance rating of hours.. Openings in the exterior wall, facing the reduced open space, shall have open ing protectives with a fire-resis - tance rat ing of hours. 07. Group - build ings. The area of a one-story, Group - build ing used as a church, community hall, dance hall, ex - hibition hall, gymnasium, lecture hall, in door swim ming pool or tennis court of Type I or II con struc tion shall not be limited when all of the following criteria are met:. The build ing shall not have a stage other than a platform.. The build ing shall be equipped through out with an auto - matic sprin kler sys tem in ac cor dance with ec tion The as sem bly floor shall be lo cated at or within inches ( mm) of street or grade level and all exits are pro - vided with ramps complying with ec tion 00. to the street or grade level.. The build ing shall be surrounded and ad joined by public ways or yards not less than 60 feet (8 88 mm) in width High-hazard use groups. Group H-, H- and H- fire areas shall be permitted in unlimited area buildings having oc - cu pan cies in Groups F and, in ac cor dance with the lim i ta tions of this section. Fire ar eas lo cated at the per im e ter of the unlim - ited area build ing shall not ex ceed 0 percent of the area of the building nor the area lim i ta tions specified in Table 0 as mod - ified by ection 06., based upon the per cent age of the perim - e ter of the fire area that fronts on a street or other un oc cu pied space. Other fire areas shall not ex ceed per cent of the area lim i ta tions specified in Table 0. Fire-resistance-rating re - quire ments of fire bar rier as sem blies shall be in accordance with Table ircraft paint hangar. The area of a one-story, Group H- air craft paint hangar shall not be limited where such air - craft paint han gar complies with the pro vi sions of ec tion. and is en tirely surrounded by public ways or yards not less in width than one and one-half times the height of the building Group E buildings. The area of a one-story Group E building of Type II, III or IV construction shall not be limited when the following criteria are met:. Each classroom shall have not less than two means of egress, with one of the means of egress being a direct exit to the outside of the building complying with ec tion 07.. The building is equipped throughout with an automatic sprin kler sys tem in ac cor dance with ection The building is surrounded and ad joined by public ways or yards not less than 60 feet (8 88 mm) in width Motion picture the aters. In build ings of Type I or II con struc tion, the area of one-story mo tion pic ture theaters shall not be limited when the build ing is provided with an automatic sprin kler sys tem through out in ac cor dance with ec tion and is surrounded and ad joined by public ways or yards not less than 60 feet (8 88 mm) in width. ECTION 08 PECIL PROVIION 08. General. The provisions in this sec tion shall permit the use of special con di tions that are ex empt from, or mod ify, the specific requirements of this chap ter regarding the allowable heights and ar eas of buildings based on the occupancy classifi - ca tion and type of construction, provided the special con di tion com plies with the provisions specified in this section for such con di tion and other applicable requirements of this code. 08. Group - en closed parking garage with Group, B, M or R above. basement and/or the first story above grade plane of a build ing shall be con sid ered as a sep a rate and dis tinct building for the purpose of de ter min ing area limitations, conti - nu ity of fire walls, limitation of num ber of sto ries and type of con struc tion, when all of the following con di tions are met:. The basement and/or the first story above grade plane is of Type I con struc tion and is sep a rated from the build - 00 INTERNTIONL BUILDING CODE 77

6 GENERL BUILDING HEIGHT ND RE ing above with a hor i zon tal as sem bly having a minimum -hour fire-re sis tance rating.. haft, stairway, ramp or es ca la tor enclosures through the hor i zon tal as sem bly shall have not less than a -hour fire-resistance rating with opening protectives in ac cor - dance with Table 7.. Ex cep tion: Where the en clo sure walls below the hor - i zon tal assembly have not less than a -hour fire-resis - tance rating with open ing protectives in accordance with Table 7., the en clo sure walls extending above the hor i zon tal assembly shall be permitted to have a -hour fire-re sis tance rating provided:. The building above the hor i zon tal assembly is not re quired to be of Type I construction;. The en clo sure connects less than four stories, and. The en clo sure opening protectives above the hor i zon tal as sem bly have a minimum -hour fire pro tec tion rating.. The building above the hor i zon tal assembly con tains only Group having an as sem bly room with an oc cu - pant load of less than 00, or Group B, M or R; and. The building below the horizontal assembly is a Group - en closed parking garage, used for the parking and stor age of private mo tor vehicles. Ex cep tions:. En try lobbies, mechanical rooms and similar uses in ci den tal to the op er a tion of the build ing shall be per mit ted.. Group having an assembly room with an oc - cupant load of less than 00, or Group B or M shall be per mit ted in ad di tion to those uses inci - den tal to the operation of the building (includ - ing stor age ar eas), pro vided that the entire struc ture below the hor i zon tal as sem bly is pro - tected through out by an approved automatic sprin kler sys tem.. The maximum build ing height in feet shall not ex ceed the lim its set forth in Ta ble 0 for the least restrictive type of con struc tion involved. 08. Group - en closed parking garage with Group - open parking garage above. Group - en closed parking garage located in the basement or first story below a Group - open parking garage shall be classified as a separate and dis - tinct building for the purpose of determining the type of con - struc tion when the following con di tions are met:. The allowable area of the struc ture shall be such that the sum of the ra tios of the actual area di vided by the allow - able area for each sep a rate occupancy shall not ex ceed.0.. The Group - en closed park ing ga rage is of Type I or II con struc tion and is at least equal to the fire-resistance re - quire ments of the Group - open parking ga rage.. The height and the num ber of the floors above the base - ment shall be limited as specified in Ta ble The floor as sem bly separating the Group - en closed park ing garage and Group - open parking ga rage shall be protected as re quired for the floor as sem bly of the Group - en closed parking garage. Open ings be tween the Group - en closed park ing ga rage and Group - open parking garage, except exit open ings, shall not be required to be pro tected.. The Group - en closed park ing ga rage is used ex clu - sively for the parking or stor age of private motor ve hi - cles, but shall be permitted to contain an office, wait ing room and toilet room having a total area of not more than,000 square feet (9 m ), and mechanical equip - ment rooms in ci den tal to the op er a tion of the building. 08. Parking be neath Group R. Where a max i mum one-story above grade plane Group - park ing ga rage, en - closed or open, or com bi na tion thereof, of Type I construction or open of Type IV construction, with grade entrance, is pro - vided un der a build ing of Group R, the num ber of sto ries to be used in determining the min i mum type of construction shall be mea sured from the floor above such a parking area. The floor as sem bly be tween the parking garage and the Group R above shall comply with the type of construction re quired for the park ing garage and shall also provide a fire-re sis tance rating not less than the mixed occupancy separation re quired in ec - tion Group R- buildings of Type III construction. The height lim i ta tion for buildings of Type III con struc tion in Group R- shall be in creased to six sto ries and 7 feet ( 860 mm) where the first-floor construction above the base ment has a fire-resistance rating of not less than hours and the floor area is subdivided by -hour fire-re sis tance-rated fire walls into ar - eas of not more than,000 square feet (79 m ) Group R- buildings of Type II construction. The height limitation for build ings of Type II construction in Group R- shall be in creased to nine stories and 00 feet (0 80 mm) where the building is separated by not less than 0 feet ( 0 mm) from any other building on the lot and from prop - erty lines, the exits are segregated in an area en closed by a -hour fire-resistance-rated fire wall and the first-floor con - struc tion has a fire-re sis tance rating of not less than / hours Open parking garage beneath Groups, I, B, M and R. Open parking ga rages constructed under Groups, I, B, M and R shall not exceed the height and area lim i ta tions permitted un der ection 06.. The height and area of the por tion of the building above the open park ing garage shall not ex ceed the lim i ta tions in ection 0 for the upper occupancy. The height, in both feet and stories, of the portion of the building above the open parking garage shall be mea sured from grade plane and shall in clude both the open parking ga rage and the por tion of the building above the parking garage Fire separation. Fire separation as sem blies be - tween the park ing occupancy and the upper occupancy shall cor re spond to the re quired fire-re sis tance rat ing pre scribed in Table 0.. for the uses involved. The type of construc - tion shall apply to each occupancy individually, ex cept that struc tural mem bers, including main bracing within the open park ing struc ture, which is necessary to sup port the upper oc cu pancy, shall be protected with the more restrictive INTERNTIONL BUILDING CODE

7 GENERL BUILDING HEIGHT ND RE fire-re sis tance-rated as sem blies of the groups involved as shown in Table 60. Means of egress for the upper oc cu - pancy shall conform to Chapter 0 and shall be sep a rated from the park ing occupancy by fire bar ri ers hav ing at least a -hour fire-re sis tance rat ing as re quired by ection 706, with self-closing doors complying with ection 7. Means of egress from the open parking garage shall comply with ection INTERNTIONL BUILDING CODE 79

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