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HomeMy WebLinkAboutJOE LAIRD & CHUCK WILLIAMS - CITY OF REXBURG - LETTERS�w� w crosL m; s'rcan COP! p BOARD OF DIRECTORS CHAIRMAN RON PERKEREWICZ, C.B.O. DIRECTOR OF. COMMUNITY DEVELOPMENT COUNTY OF KITSAP PORTORCHARD, WASHINGTON FIRST VICE-CHAIRMAN THOMAS R. THOMPSON, C.B.O. BUILDING OFFICIAL BROOMFIELD. COLORADO SECOND VICE-CHAIRMAN ALAN P. OLSON, R.A., C.B.O. ASSISTANT DEVELOPMENT SERVICES DIRECTOR PHOENIX, ARIZONA IMMEDIATE PAST CHAIRMAN JAN P. GASTERLAND, C.B.O. BUILDING CODE OFFICER ST. PAUL, MINNESOTA International Conference of Building Officials REGIONAL OFFICE: 2122 -112th AVENUE, N.E.,SUITE 6-300 P BELLEVUE, WASHINGTON 98004 • (206) 451-9541 THOMAS C. ANDERSON BUILDING OFFICIAL HOPKINS, MINNESOTA FRED B. CULLUM BUILDING OFFICIAL BURLINGAME, CALIFORNIA PAUL T. EDGERTON MANAGER, BUILDING AND CODE ENFORCEMENT VANCOUVER, WASHINGTON ROGER R. EVANS. C.B.O. DIRECTOR OF BUILDING SERVICES SALT LAKE CITY, UTAH FRED HERMAN CHIEF BUILDING OFFICIAL PALO ALTO.CAUFORNIA KENNETH G. LARSEN, C.B.O. DIRECTOR OF BUILDING AND HOUSING CHULA VISTA, CALIFORNIA DAN R. HICKLE, C.B.O. CODES ADMINISTRATOR LAKEWOOD, C16LOMM RONALD L. NIMABER, C.B.O. DIRECTOR OF INSPECTIONS MAPLE GROVE, MINNESOTA JOHN E. PIERCE, C.B.O. BUILDING OFICIAL PLANO. TEXAS LARRY W. RICHARDS, C.B.O. BUILDING SAFETY DIRECTOR GLENDALE. ARIZONA RAIMAR W. SCHULLER. C.B.O. DIRECTOR, BUILDING DEPARTMENT NEWPORT BEACH, CALIFORNIA BON K. WATTS, C.B.O. CHIEF OF BUILDING INSPECTIONS BUILDING SAFETY DIVISION ANCHORAGE, ALASKA PRESIDENT JON S. TRAW. P.E. May 23, 1996 OFFICES OF JERRY J. BARBERA, P.E. SENIOR REGIONAL MANAGER Rexburg, Idaho 83440 Subject: Definitions of Grade and Story, Escape Window Height, and Number of Exits Off of a Exit Balcony Sections 208, 220, 310.4, and 1005.1, 1994 Edition of the Uniform Building CodeTm Dear Mr. Laird, I apologize for the lateness of the reply to your letter we received on April 15th. It concerned a continuing discussion of the subject of grade and story which I addressed in an earlier letter on March 13th. Unfortunately, this time of year is the most hectic and overloaded. We didn't get a chance until now to address your concerns. I will paraphrase your questions and give a consensus answer. Q. 1. For the building shown in Figure IA, is line x -x or z -z the one I should be using in order to determine the lowest grade within 5'-0"? I get a completely different answer about number of stories depending on which one I use. Please discuss the rationale and history of these definitions. A. 1. Since the lowest floor is the one that could be a story or basement, and since the definition of "exterior wall" would be assigned to line x -x on the lower floor (it ivould he line 2.-.. on the upper ones), then line x -x should be used for determination of grade and story. The reason for measuring grade as defined relative to a plane 6'-0" below the upper floor and specifically the lowest grade within T-0" of that exterior perimeter was developed due to abuse of the concept in the past. The whole point of determining stories and heights relate to the difficulty of fighting fires and rescuing occupants in the buildings. Hillside locations are the biggest problems because the fire personnel may have to approach the building from the worst possible direction. Imagine the difficulty of maneuvering a ladder on a slope or having one long enough to reach the upper stories when on the sloping side. That is the reason for requiring the lowest levels to be stories regardless of percentage of perimeter which is above the plane 6'-0" below if any point is 12'-0" or more below the floor above. Main Office: 936n \Norknrn Mill RoJd • Whillier, California 90601-2298 9 (310)691)-01,41 KATHLEEN CURRY, P.E. Joseph A. Laird, F.E. REGIONAL ENGINEER City Engineer/Building Official GREG GRIFFITH REGIONAL ENGINEER City of Rexburg CHARLES J. WILLIAMS, RE, S.E. P.O. BOX 280 SENIOR REGIONAL ENGINEER Rexburg, Idaho 83440 Subject: Definitions of Grade and Story, Escape Window Height, and Number of Exits Off of a Exit Balcony Sections 208, 220, 310.4, and 1005.1, 1994 Edition of the Uniform Building CodeTm Dear Mr. Laird, I apologize for the lateness of the reply to your letter we received on April 15th. It concerned a continuing discussion of the subject of grade and story which I addressed in an earlier letter on March 13th. Unfortunately, this time of year is the most hectic and overloaded. We didn't get a chance until now to address your concerns. I will paraphrase your questions and give a consensus answer. Q. 1. For the building shown in Figure IA, is line x -x or z -z the one I should be using in order to determine the lowest grade within 5'-0"? I get a completely different answer about number of stories depending on which one I use. Please discuss the rationale and history of these definitions. A. 1. Since the lowest floor is the one that could be a story or basement, and since the definition of "exterior wall" would be assigned to line x -x on the lower floor (it ivould he line 2.-.. on the upper ones), then line x -x should be used for determination of grade and story. The reason for measuring grade as defined relative to a plane 6'-0" below the upper floor and specifically the lowest grade within T-0" of that exterior perimeter was developed due to abuse of the concept in the past. The whole point of determining stories and heights relate to the difficulty of fighting fires and rescuing occupants in the buildings. Hillside locations are the biggest problems because the fire personnel may have to approach the building from the worst possible direction. Imagine the difficulty of maneuvering a ladder on a slope or having one long enough to reach the upper stories when on the sloping side. That is the reason for requiring the lowest levels to be stories regardless of percentage of perimeter which is above the plane 6'-0" below if any point is 12'-0" or more below the floor above. Main Office: 936n \Norknrn Mill RoJd • Whillier, California 90601-2298 9 (310)691)-01,41 Joseph Laird, City of Rexburg May 23, 1996 Page 2 I have seen how these definitions have changed in the last 25 years and remember the times when developers or designers would put portable planters at various locations along the exterior wall to pretend that there was some sort of grade there. They tried to make a four-story building look like a three-story one and so forth. The 5'-0" rule was added to make it harder to corrupt the intent. Unfortunately, there is still a tendency of some to build a building on flat earth and push up a 5'-0" wide swath of dirt around various parts of the building and pretend it is something is not. Even more unfortunate is a implication in our newest Handbook to the UBC that this is something one can do. Q. 2. What would happen if in Figure 1B there were a structural post and beam arrangement along line z -z. Wouldn't the exterior wall now be there by definition? Wouldn't I have exactly the same situation but now the building would be considered a two -stories over a basement instead of three stories.? What gives? A. 2. Yes, you have a good point, by definition the post and beam would form the exterior boundaries of the building and you would get a different answer than in Figure IA. The only reason I can give is that this explains one of the difficulties of defining a concept adequately enough so that no "loopholes" appear for specific applications. The most probable reason is that this situation is not exactly like the ones which pushed the definition in the past. You could probably think of the exit walkway as a long window well. By the way, in either of the two situations, the provisions of Section 1203.1 and specifically exception 1 to that section would apply and the 9' to 10' high space from the walkway to the bottom of the exterior balcony above would be less than 65% open! Q. 3. Some of the older apartment buildings in our neighborhood have properly sized escape windows but the bottoms of the windows are 50" to 51" above the floor. Would putting in a 6" or 7" step be an acceptable alternative to making the window sills lower to comply with the code? A. 2. It may be that nothing is necessary. What is unclear is whether these older apartments were required to follow the escape window requirements when they were built. If not, then Section 3401 allows an existing building built legally to enjoy "preexisting rights," so to speak, and does not require them to be brought up to today's code provisions. If they were built at the time when escape windows were required, it may be that they are "existing -nonconforming" in which case your City Attorney should be consulted about whether mitigation requirements such as a step are required. There are some practical problems with putting a step there because it may disrupt the use of the room, there is no guarantee that the tenant or owner will leave it there if it is deemed less than useful for other reasons than life -safety. Under Section 3401 the key phrase is, ..... provided such continued use is not dangerous to life." This is probably controlled by Section 102 where you have to determine if the situation "unsafe." You should be aware, however, that prior to the 1976 edition of the UBC that the height of the sill was allowed to be 48" from the finish,Jloor surface (emphasis mine) and that there may have been something on the floor that made up the 2" difference. Joseph Laird, City of Rexburg May 23, 1996 Page 3 If you are writing about the use of replacement windows in these buildings, then Section 3403.4 would apply. The staff consensus is that if the frame around the opening is not made larger than the existing one (subject to the discussion above about what provisions applied when it was originally done), then today's requirements for escape windows would not apply. Q. 4. I believe you misunderstood me in your March 13th reply to a previous question I had concerning protection of walls and openings in a "dead-end" condition beyond one stairway in an apartment building that requires two exits from the floor. In the exceptions to Section 1003.1 two exits are required only when the floor serves 10 or more occupants and, correspondingly, Section 1005.7 only renuires that a corridor or exterior exit balcony have fire protection when the occupant load is 10 or more. Consequently, if the 3 apartments to the left of the stairway in Figure 4 had 10 or more occupants then another set of stairs (3 total) would be required and if they had less than 10, then fire protection is not required. Therefore, it seems to me that Figure 4 which is reprinted from a code update class I took would never require protection. Am I right? A. 4. Not necessarily. I think the key word you are neglecting in both Sections 1003.1 and 1005.7 is Served. That means when you identify the exterior exit balcony, then, in general, its entire length serves the total occupant load. It is not broken into two segments, one between the two stairways and one to the left of the left stairway. Therefore, whether on not there are 10, or more than 10 or less than 10 occupants in the dead-end portion to the left of the left stairway only two exits are required period. The situation this provision is trying to correct is where the left stairway is potentially contaminated by smoke or fire and the occupants to the left of it would not easily get to the far right stairway which would be the "emergency exit" in this case. The contamination would probably be from the apartments themselves to the left of the stairway and to mitigate the possibility, the openings in them are protected with fire assemblies not required elsewhere along the exit balcony. I said that this answer is generally correct. You would be possibly right in one of your points about a third stairway being required to the left of the apartments if the dead-end became longer than 20'-0". I hope that this answers your questions adequately, but please feel free to call me if you require any other information. Thank you for your interest in uniformity of code administration. Very truly yours,/04 �� J. Barbera, P.E. Regional Manager pkw p JYC3 CA IY •Jh;e^LN �` $i 2A'J'dA «„ cane ni� Y d'J'1FN'b/ BOARD OF DIRECTORS CHAIRMAN DEVELOPMENT COUNTY OF KITSAP PORT ORCHARD, WASHINGTON FIRST VICE-CHAIRMAN THOMAS R. THOMPSON. C.B.D. BUILDING OFFICIAL BROOMFIELD. COLORADO SECOND VICE-CHAIRMAN ALAN P. OLSON, R.A., C.B.O. ASSISTANT DEVELOPMENT SERVICES DIRECTOR PHOENIX, ARIZONA IMMEDIATE PAST CHAIRMAN JAN R GASTERLANO, C.B.O. BUILDING CODE OFFICER ST. PAUL, MINNESOTA THOMAS C. ANDERSON BUILDING OFFICIAL HOPKINS. MINNESOTA FRED B. CULLUM BUILDING OFFICIAL BURLINGAME, CALIFORNIA PAUL T. EDGERTON MANAGER, BUILDING AND CODE ENFORCEMENT VANCOUVER, WASHINGTON ROGER R. EVANS, C.B.O. DIRECTOR OF BUILDING SERVICES SALT LAKE CITY, UTAH FRED HERMAN CHIEF BUILDING OFFICIAL PALO ALTO. CALIFORNIA International Conference of Building Officia s REGIONAL OFFICE: 2122 -112th AVENUE, N.E., SUITE B-300 • BELLEVUE, WASHINGTON 90004 • (206) 451-9541 KENNETH G. LARSEN, C.B.O. DIRECTOR OF BUILDING AND HOUSING CHULA VISTA, CALIFORNIA DAN R. NICKLE, C.B.O. CODES ADMINISTRATOR LAKEWOOD, COLORADO RONALD L NIMABER, C.B.O. DIRECTOR OF INSPECTIONS MAPLE GROVE, MINNESOTA JOHN E. PIERCE, C.B.O. BUILDING OFICIAL PL NO. TEXAS LARRY W. RICHARDS. C.B.O. BUILDING SAFETY DIRECTOR GLENDALE, ARIZONA RAIMAR W SCHULLER, C.B.O. DIRECTOR, BUILDING DEPARTMENT NEWPORT BEACH, CALIFORNIA RON K. WATTS, C.B.O. CHIEF OF BUILDING INSPECTIONS BUILDING SAFETY DIVISION ANCHORAGE, ALASKA March 13, 1996 Joe Laird City Engineer and Building Official P. O. Box 280 Rexburg, Idaho 83440 OFFICES OF JERRY J. BARBERA, P.E. SENIOR REGIONAL MANAGER KATHLEEN CURRY, P.E. REGIONAL ENGINEER GREG GRIFFITH REGIONAL ENGINEER CHARLES J. WILLIAMS, P.E., S.E. SENIOR REGIONAL ENGINEER SUBJECT: Determination of number of stories when the building is divided by an area separation wall; opening protection in an exit balcony. Sections 208, 220 and 1005.8.2 1994 edition of the Uniform Building Code' Dear Mr. Laird: We received your faescimile transmission on February 22 concerning a potential three-story building in your city. Your questions concern the point about which one measures the perimeter for determination of distance below the upper floor of the building when an area separation wall is involved. I will paraphrase your question to make it general and answer your question. Q1. I am trying to apply the definition of story to the apartment building shown in the enclosed sketch and Section B -B. When an area separation wall is involved do you ignore its length? And if there is a exterior jog in the building there where do you measure to to determine how much it is below or above the imaginary plane relative to the floor above the potential basement or story? Al. The code is silent on this subject. In general any of the alternatives you mentioned could be used but the fairest one would be to take an average of the elevation on each end of the wall. In general one would measure the location of the imaginary PRESIDENT plane from which to determine percentage of perimeter above JON S. TRAW. RE. or below it relative to the portion of the building (1 or 2) you are studying. In your specific case of building 1 you would use the 5'-311 dimension from the middle floor. In the case of building 2, you would measure from the second floor down to the grade not to the (below grade?) first story. Main Office: 5360 Workman Mill Road 0 Whittier, California 90601-2298 • (310) 6990541 Joe Laird, City of Rexburg March 15, 1996 Page 2 Q2. When an exterior balcony extends beyond the edge of the building as shown in Section A- A, and there is a retaining wall underneath it which forms a below -grade exit walkway, does one still measure the "adjacent grade level" from the walkway well side or from the grade 5' measured outwardly from the edge of the balcony? A2. It would be our opinion that the definition of FLOOR AREA plays a part in the answer to your question since the definition of story includes the words "floor". Although it no longer repeats this, earlier editions of the Handbook to the UBC stated that an exterior balcony was not to be considered part of floor area. In general, it and overhangs are considered projections beyond to floor area. That being the case one would measure from the walkway well inside face of the permeter. Your figure 3 would agree with this because it is the lowest point within 5'-0" of the exterior wall (emphasis is ours). Q3. When an exterior exit balcony is required and in the case of apartments, do only the interior walls and ceiling portion of the one-hour floor or roof/ceiling assembly have to be protected or do the openings have to be protected also? A3. Although the balcony is a special case of a corridor, only the walls and ceiling have to be protected if it is possible for the occupants to exit in 2 directions. (See exception Section 1005.8.2). The reason that the openings don't need protection is because the open sides of the balcony are considered to allow smoke to discharge to the atmosphere. That way the smoke will not completely engulf the the exit pathway as they would if they were enclosed on all sides like in a corridor. Also with two ways off the balcony one has a better chance than normal to get off the balcony quickly. Q4. Since two exits are required in all cases when the Occupant Load reaches 10 and this is also the time when protection is required, when would one ever require protection of openings? A4. Your illustration no. 4 correctly shows when it is required. The whole balcony requires two exits and they are clearly shown. However, occupants of the apartments to the left of the inboard stairway cannot exit in two directions. Were there to be a fire between these three apartments and the stairway, then the extra level of safety I mentioned would be gone. Therefore, any doors or windows into these apartments would require protection. I am hopeful that this provides an answer to your questions. If you require further assistance please feel free to call. Thank you for your interest in the uniformity of code administration. Very truly yours, Jerry J. Barbera, P.E. spm Senior Manager c/ Rick Okawa N ore co= ify F� 9 STATE OF IDAHO 4aCISHEO NILE L. BOYLE WWR ROSE BAGLEY CLEPI( RICHARD HORNER February 22, 1996 IPGSUPEP B EINWAL NMEP To: Mr. Jerry Barbera or Mr. Chuck Williams ICBG Regional Office 2122 - 112th Ave. N.E., Suite B-300 Bellevue, Washington 98004 Tel. 206-451-9541 or FAX 206-637-8939 From: Joe Laird, City Engineer & Building Official P.O. Box 280 Rexburg, Idaho 83440 Tel. 208-359-3020, Ext. 324 or FAX 208-359-3022 I.C.B.O. #0468770 D P.O. BOX 280 12 NORTH CENTER STREET REXBURG, IDAHO 83440 PHONE (208) 359-3020 FAX (208) 359-3022 A mutual acquaintance, George Klomp, Building Official at Idaho Falls, Idaho, suggested I contact you with a code interpretation problem we have encountered. We are evaluating an existing building to determine whether it is a 3 story building or a 2 story building with a basement. (See attached Figure 1.) Our concern is with the interpretation of Sec. 208 -GRADE and Sec. 220 -STORY (94 UBC). On the west side of the building, the distance from finished 'floor to grade is 512" to 5'7" - (no problem). On the north side, the distance from finished floor to grade is 6' to 7' (over the 6' limit) The east side of the building is predominantly a 2 -hour Area Separation Wall between buildings. Approximately a 4 foot length of this wall would have a 512" distance from finished floor to ground surface. How does one measure the "finished- floor- to- grade" dimension where the Area Separation Wall is? Would it be the 611" distance from the finished floor of the middle floor of Building #1 to the top of the 1st floor of Building #2? (See Sec. B -B of Figure 1) Or does one ignore the "grade" dimension through the Area Separation Wall area? Or does one average the grade on the north side (6' to 7') and the 512" grade, for the 4' length of Building #1 south of Building #2? The south side of the building has exterior exit balconies on the top and middle floors and an exterior walkway along the full length of the bottom floor. This exterior walkway is 42" in width from the edge of the building to the inside edge of the retaining wall. The retaining wall is 8" thick. How does one measure the "finished floor -to -grade" dimension here? The definition of "Grade" says it "is the lowest point of elevation of the finished surface of the ground, paving or sidewalk within the area between the building and --- a line 5 feet from the building. To me, this says I should be measuring from the finished floor to the top surface of the exterior walkway (9 ft.). I think the top of the exterior walkway is the same as the term "sidewalk" listed in the definition. I also base this on Figure 2 (copy attached) which was given as an example of "grade" at an I.C.B.O. class I attended. Others in this area say no: "The exterior exit walkway and retaining wall are part of the building and that the measurement should be from finished floor to the top of the parking lot surface south of the retaining wall (5'6" to 6'8" height dimension) citing CASE 1 in the UBC Application / Interpretation Manual. (Attached as Figure 3). Could you please clarify for me how to correctly measure the floor to grade dimension in this situation? It is a very critical measurement for us as we have a number of existing college apartment houses constructed this way and several more in the final stage of design. Referring to a different subject, Section 1005.7 - Construction (94 UBC), each of the apartments (Figure 1) has an occupant load of six; therefore, the occupant load on each exterior exit balcony or the exterior walkway would be 5 apartments x 6 occupants = 30 persons (more than the occupant load of 10 required in Sec. 1005.7). Therefore, (A) the exterior wall adjacent to the exterior exit balconies and exterior walkway would have to have a 1 -hour fire resistive rating, and (B) the ceiling/roof system or ceiling/floor system above the exterior exit balconies or exterior exit walkway would have to have a 1 -hour fire -resistive rating, in my opinion. Others, in our area, say this section only applies to interior corridors. I feel that Section 1005.1 -General lumps corridors and exterior balconies together; therefor, Sec. 1005.7 should also apply to exterior exit balconies. Could you please clarify this point of controversy? It seems rather peculiar that Sec. 1005.7 would require 1 -hour fire -resistive walls (with an occupant load of 10 or more) while Sec.1005.8.1-Doors and Sec. 1005.8.2 -Openings Other Than Doors, Exception 2, states that doors and windows in the interior walls of exterior exit balconies DO NOT have to be protected when "it is possible to exit in two directions." Thus we end up with a 1 -hour fire -resistive wall but no protection for the doors and windows. This doesn't make much sense to me. Is there something I am missing here somewhere? Sec. 1003.1 Number of Exits, Exceptions 1 & 2 indicate that 2 exits are required with 10 or more occupants. With less than 10 occupants, Sec. 1005.7 says interior walls of exterior exit balconies don't have to have 1 -hour fire -resistance. Therefore, I don't see any set of circumstances that would ever require fire protected doors and windows on exterior exit balconies: consequently Figure 4 (copy attached) that I got at one of the I.C.B.O. schools would be incorrect as fire protected doors and windows would never be required to have a fire protection rating. Thank you for your help with these interpretations. GRADE FLOOR ELEVATION GRADE 100' 5' A -A • F.G. 96' yr----------------------------�F.G. 103 1 I I I I I A I y l A �I I I I FLOOR I ELEVATION I 100' Ib I I • I I I I I , B i B I I I F.G. I 103' --------------------------- F.G.� F.G. 102 104' GRADE GRADE FLOOR / ELEVATION 100' 5' 5' B -B GRADE - (ADJACENT GROUND ELEVATION) Section 408 FiFIGI I f� r_ CHAPTER 4 G V ! V F�_ — 9 Definitions and Abbreviations Section 408—GRADE Section 409—HABITABLE SPACE p° (Adjacent Ground Elevation) Sec. 409. Sec. 408. GRADE (Adjacent Ground Elevation) is the lowest point of eleva- tion of the finished surface of the ground, paving or sidewalk within the arca between the building and the properly line or, when the property line is more than 5 feet from the building, between the building and a line 5 feet from the building. Q. May a relaining wall be used for the purpose of raising . the effective elevation of finished grade? The use of a retaining wall to raise the elevation of the III finished surface of the ground would be permissible, provided the outside face of the retaining wall is at least 5 feet from the exterior wall line of the building, or al the properly line, if a lesser distance. Likewise, the finish grade may be raised by the use of built-up grade, provided the built-up areas are at least 5 feet wide. Case I and Case II illustrate these two conditions. 5'-0' MIN. OR !L IF CLOSER CASE CASE II 5 0' MIN. OR it IF CLOSER 5' 0- MIN. OR It IF CLOSER HABITABLE SPACE (ROONI) is a space in a structure For living. sleeping, eating or cooking. Bathrooms, toilet compartments, closets. halls, storage or utility space, and similar areas, are not considered habitable space. We typically have houses constructed which contain . unfinished basements or lower levels. Would these basements or usable portions thereof be considered as habitable space? A■If the space had closets, floor covering, electrical wiring ■ and other facilities in place which make the space usa- ble for living, sleeping, eating or cooking, then the space would be considered habitable space. If the area or space has bare walls, floors and ceilings (which is the common condition in which most new homes are finished), we would not consider the space to be habitable. The space most commonly is used for storage or utility. Section 409—HEIGHT OF BUILDING Sec. 409. HEIGHT OF BUILDING is the vertical distance above a reference datum measured to the highest point of the coping of a Ilan roof or to the deck line of a mansard roof or to (lie average height of the highest gable of a pitched or hipped roof. The reference datum shall be selected by either of the following, whichever yields a greater height of building: I. The elevation of the highest adjoining sidewalk or ground sur- face within a 5 -foot horizontal distance of the exterior wall of the building when such sidewalk or ground surface is not more than 10 feet above lowest grade. 2. An elevation 10 feel higher than the lowest grade when the sidewalk or ground surface described in Item I above is more than 10 feet above lowest grade. The height of a stepped or terraced building is the maximum height of any segment of the building. Q■Could you graphically illustrate how to locate the refer- IIIence datum mentioned in Section 409 and used for determining the height of a building? A■ In the following drawings, Case I corresponds to Item ■ No. 1 underthe definition for "height of building" while Case II relates to Item No. 2. In both Cases I and II, elevation 0 represents the highest elevation within 5 feet of the exterior wall of a building, and elevation A represents the lowest elevation within 5 feet of the exterior wall of a building. When elevation A is less than 10 feet below elevation 0, the datum from which to measure the height of a building is elevation B and should be determined as indicated in Case I. When elevation A is more than 10 feet below elevation B, a datum which is 10 feet above elevation A is first determined. The height of the building is then measured from this last established elevation as indicated in Case 11, Protection of openings in the Interior walls of exterior exit balconies is not required when it Is possible to exit In two directions. Protection of openings required •20 minute doors • 314 hour for all.. other openings Protection of openings not required \ Exterior exit balcony CORRIDORS AND EXTERIOR EXIT BALCONIES Section 3305 (h) Q SOCCER FIELD SPRINKLER MATERIAL LIST ITEM UNITS SUM UNIT COST TOTAL 1-%' Non Pressure Pipe feet 1925 2" Pressure Pipe feet 240 6" to 2" Saddle each I 2" Corporation each 1 2" Curb Stop each 1 1-%2" Automatic Valves each 6 Valve Boxes each 6 2" to 1-%2" Tees with Clamps each 6 1-%2" to %2" Saddle for I-40 heads each 40 1-%2" to '/2" L's with clamps each 6 Hunter I-40 Full Circle Heads each 24 Hunter I-40 Part Circle Heads each 16 Swing Joint Risers for 1-40 Heads each 40 8 Station Controller each 1 Controller Jumbo Box each 2 Direct Burial Control Wire - 8 Valves feet 500 Total