apply  to  definitive  designs  and  standard  drawings and also to project specifications. EFDs and A/Es are  allowed  latitude  in  new  concepts,  creative thinking, and the use of new materials; however, when   deviations   from   mandatory   criteria   are considered,  they  need  to  obtain  prior  clearance from   NAVFACENGCOM   headquarters. For dimensions on project drawings, you may use customary U.S. dimensions unless the project is in an area in which System International (SI) is  normally  used.  The  International  System  of Units  is  the  internationally  accepted  “metric” system.  Use  of  the  word  metric  is  no  longer  an accepted  practice.  For  details  of  the  proper  use of SI units, refer to ASTM E380-82, Standard for Metric   Practice,   for  generic  conversions,  and ASTM  E621-79,  Recommended  Practice  for  the Use of Metric (SI) Units in Building Design and Construction, for conversions in engineering and design. ORDER  OF  DRAWINGS Project drawings for buildings and structures are  arranged  in  the  following  order: 1.   TITLE   SHEET   AND   INDEX—Contains specific  project  title  and  an  index  of  drawings. (Used  only  for  projects  containing  60  or  more drawings). 2.  PLOT  OR  VICINITY  PLANS—Contain either plot or vicinity plans or both, as well as civil and  utility  plans.  For  small  projects,  this  sheet should  include  an  index  of  the  drawings. 3.   LANDSCAPE   AND   IRRIGATION   (if applicable). 4.   ARCHITECTURAL   (including   interior design  as  applicable). 5.  STRUCTURAL. 6.  MECHANICAL  (heating,  ventilation,  and air  conditioning). 7.   PLUMBING. 8.  ELECTRICAL. 9.   FIRE   PROTECTION. DRAWING  SHEET  SIZE  AND  FORMAT The   following   should   be   used   for   NAV- FACENGCOM  drawings: TYPE SIZE  (IN  INCHES) Flat 17 x 22 (C size) - When small sheets are required Flat 22 x 34 (D size) - for project and other drawings Flat 28 x 40 (F size) - option to 22 x 34 Refer to chapter 3, figure 3-14 for finished draw- ing  and  format  and  margins. Title Blocks The   title   block   indicates   the   name   and location  of  the  activity  preparing  the  drawing, drawing   title   and   number,   approval   within the  activity  and  by  an  activity  other  or different than the source preparing the drawing, and  other  information  relative  to  preparation of   the   drawing, such   as   the   predominant scale   used,   drawing   size   letter   designation, and  sheet  number  for  multiple  sheet  drawings. The  code  identification  number  or  Federal Supply Code for Manufacturers (FSCM) “80091” is  required  in  the  title  block  of  all  NAV- FACENGCOM  drawings.  Vertical  title  block format   is   used   for   all   22-   by   34-in.   (D-size) drawings;  whereas,  use  of  vertical  title  block is  optional  for  28-  by  40-in.  (F-size)  drawings. The   layout   and   format   for   title   blocks   are shown in chapter 3, ANSI   Y14.1-1980. Drawing Numbers figures 3-15 to 3-21, and in NAVFACENGCOM drawing numbers issued to  individual  engineering  field  divisions  are  within the  following  limits: NORTHERN DIVISION . . . . . .2 000 000 to 2 999 999 CHESAPEAKE DIVISION . . .3 000 000 to 3 999 999 ATLANTIC DIVISION . . . . . . . .4 000 000 to 4 999 999 SOUTHERN DIVISION . . . . . . .5 000 000 to 5 999 999 WESTERN DIVISION . . . . . . . .6 000 000 to 6 999 999 PACIFIC DIVISION . . . . . . . . . .7 000 000 to 7 999 999 NAVFACENGCOM   headquarters   retains custody of all of the numbers up to and including 1  999  999  and  all  other  drawing  numbers  not assigned. Each cognizant EFD is responsible for the   control   of   assigned   numbers   for   issuing, assigning,  and  recording  these  numbers  for  its own  use  or  the  use  of  activities  within  its geographical   area. Each   activity   maintains an  assignment  record  including  locations  and drawing titles of drawing numbers assigned to it. 10-5