particular room, because the changes you make will greatly  affect  other  rooms  below  it.  Errors  are  less likely to occur and revisions will be easier to handle when   each   space   in   the   schedule   is   lettered individually. Remember, whenever possible, place all of the schedules on the same sheet as their respective drawings on the building. WRITTEN   SPECIFICATIONS Because many aspects of construction cannot be shown   graphically,   even   the   best   prepared construction drawings often inadequately show some portions of a project. For example, on a drawing can anyone show the quality of workmanship required for the  installation  of  doors  and  windows,  or  who  is responsible  for  supplying  the  materials?  These  are things  that  can  be  conveyed  only  by  hand-lettered notes.  The  standard  procedure  is  to  supplement construction   drawings   with   detailed   written instructions.  These  written  instructions,  called specifications (or more commonly specs), define and limit  materials  and  fabrication  to  the  intent  of  the engineer or designer. Usually, it is the design engineer’s responsibility y to prepare project specifications. As a Builder, you will be required to read, interpret, and use these in your work as a crew leader or supervisor. You must be familiar with the   various   types   of   federal,   military,   and nongovernmental   reference   specifications   used   in preparing project specs. When assisting the engineer in preparing or using specifications, you also need to be familiar with the general format and terminology used, NAVFAC  SPECIFICATIONS The   Naval   Facilities   Engineering   Command ( N A V F A C E N G C O M )     p r e p a r e s     N A V F A C specifications and sets standards for all construction work performed under its jurisdiction. This includes work  performed  by  the  Seabees.  The  three  types  of NAVFAC specifications are covered in the following information. NAVFACENGCOM  Guide  Specifications NAVFACENGCOM guide specifications (NFGS) are the primary basis for preparing specifications for construction projects. These specifications define and establish  the  minimum  criteria  for  construction, materials,  and  workmanship  and  must  be  used  as guidance in the preparation of project specifications. Each of these guide specifications (of which there are more than 300) encompass a wide variety of different materials,  construction  methods,  and  circumstances. Therefore,  they  must  be  tailored  to  suit  the  work actually required by the specific project. To  better  explain  this,  let’s  look  at  figure  2-11 which  is  a  page  taken  from  a  NAVFACENGCOM guide  specification.  In  this  figure,  you  can  see  that there   are   two   paragraphs   numbered   3.2.1.   This indicates   that   the   spec   writer   must   choose   the paragraph  that  best  suits  the  particular  project  for which  he  or  she  is  writing  the  specification.  The capital letters I and J in the right-hand margin next to those   paragraphs   refer   to   footnotes   (contained elsewhere  in  the  same  guide  specification)  that  the spec   writer   must   follow   when   selecting   the   best paragraph. Additionally, you can see that some of the information  in  figure  2-11  indicates  other  choices  that the   spec   writer   must   make.   Guide   specifications should  be  modified  and  edited  to  reflect  the  latest proven technology, materials, and methods. EFD Regional Guide Specifications Engineering Field Division (EFD) regional guide specifications  are  used  in  the  same  way  as  the NAVFACENGCOM guide specifications but only in areas under the jurisdiction of an EFD of the Naval Facilities  Engineering  Field  Command.  When  the  spec writer is given a choice between using an EFD regional guide  specification  or  a  NAVFACENGCOM  guide specification  with  the  same  identification  number,  the writer must use the one with the most recent date. This is because there can only be one valid guide specification for a particular area at any one time. Standard   Specifications Standard  specifications  are  written  for  a  small group  of  specialized  structures  that  must  have  uniform construction  to  meet  rigid  operational  requirements. NAVFAC  standard  specifications  contain  references to federal, military, other command and bureau, and association   specifications.   NAVFAC   standard specifications   are   referenced   or   copied   in   project specifications   and   can   be   modified   with   the modification noted and referenced. An example of a standard  specification  with  modification  is  shown below. “The   magazine   shall   be   Arch,   Type   I, conforming  to  specifications  S-M8E,  except  that  all concrete shall be class F- 1.” 2-16