Packing Assets in BSA Tutorial

Jump to: navigation, search

This guide will give you step by step instructions on packing BSA and using it with your game. Several tools can be used to pack BSA but this tutorial will primarily be focused around using BSArchPro so be sure to download that before getting started. Additionally this guide operates under the assumption you have JIP LN NVSE installed.

Reasons For Packing

BSA files are superior to loose files because they decrease loading times, decrease memory usage, reduce game stutter and increase general game performance. Mods with large amounts of meshes and textures are the best targets for BSA packing. Or mods with large file sizes.

What To Pack

Not everything can be packed, some files will either not be usable by the game in BSA or will yield little to no benefit from packing. in general stick to packing only the following file types:

  • DDS (Textures)
  • NIF (Game models)
  • WAV
  • OGG
  • EGM (Files that make armor morph / fit correctly when worn, these files cannot load loose and thus must be packed)
  • EGT (Face tint)
  • LIP (NPC lip sync)
  • LST (Files for Tree LOD, rarely used)
  • SPT (SpeedTree format for Tree meshes, rarely used)

Files you should not pack as doing so either gives almost no benefit or at worst they don't load at all:

  • MP3
  • XML
  • KF (Unless you can confirm the mod you are packing does not rely on kNVSE)
  • JSON
  • INI

BSA Creation Steps

  • 1: Install and open BSArchPro. It may be helpful to read "What to Pack" section of this page and the "Notes" at the bottom of the page before proceeding.
  • 2: Pick a mod you want to pack and click and drag the "textures", "meshes" and "sound" folders from that mod into main BSA BSArchPro window (If the mods combined assets exceed 2GB then you may want to consider doing these in different sessions) Additionally do not checkmark any files as this causes compression.
  • 3: Use the filter bar at the top and search for the file formats in the list that shouldn't be packed (mainly just KF if the mod requires kNVSE) with the "." character before the extension name. And shift click to select the entire list and press delete which will remove those entries from the list.
  • 4: Once the the bad files are removed from the list hit the "Pack" button and a new window should popup.
  • 5: Check the "New Vegas" packing mode under the packing options and Uncheck the Autodetect Flags (it sometimes flags BSAs incorrectly leading to assets not loading correctly in game). Check Meshes and Retain Strings During Startup if you are packing meshes, check Textures and Embed Name if you are packing textures, check Sounds and Retain File Names if you are packing sound effects, check Voices if you are packing character dialogue.
  • 6: Set your export file directory and the name of your BSA after the mods ESM or ESP file (if the mod doesn't have one you can name it after the last ESP in your load order) and click OK.
  • 7: BSA will be created in the directory you set and a popup will appear asking if you want to create an override file (click the button to create the override file).
  • 8: Drag the BSA and override file you created to the mods folder.
  • 9: In your mod folder delete the folders you previously packed into your BSA (make sure you have a backup). If you had to exclude files from the packing process then instead you will have to use windows file explorer and search for files by typing in the file extension (*.NIF for example) and shift click all files in the list and delete all the files.
  • 10: Verify your BSA and override file are named after the ESP or ESM you are hooking to and test in game.

Reason Assets Might Not Be Loading In Game

  • BSA is not hooked to a ESP or ESM. This is because either the BSA is named after a ESP or ESM that doesn't exist or the name is misspelled.
  • BSA doesn't have an overwrite file or doesn't have a matching name with the BSA it's paired with.
  • You've packed assets that cannot be used in BSA like MP3s, DLLs or INI.
  • A loose file is overwriting an asset in the BSA. With an LOD conflict this can cause broken visuals such as black boxes in the distance.
  • BSA is hooked to a ESM or ESP that doesn't have a master file (such as an ESM), doing so will result in the BSA not loading. Both MO2 and xEDIT can show you what masters a ESM or ESP has.
  • BSA shares the EXACT same name as another BSA in your load order, this will cause the BSA highest in your load order to be effectively ignored.
  • BSA is over 2GB in size.
  • The ESP or ESM the BSA is hooked to is not enabled in your load order.
  • Wrong flags were set in the "Packing Options" window in BSArchPro or in a similar program.
  • Another BSA with the same asset (such as Update.BSA) is lower in your load order and is winning the conflict (try rearranging your load order).


  • You can hook multiple BSAs to a single ESP or ESM by renaming the end of the BSA filename anything you want separated by a space (for example "NVMIM 2" is correct and "NVMIM2" is wrong), but the beginning must match the name of a ESP or ESM you are hooking to.
  • Do not pack the "Music" or "Menus" folders, for music MP3s cannot load in BSA and you gain nothing from packing XML when you use "UIO - User Interface Organizer".
  • Files packed in BSA always get overwritten by loose files if a file conflicts regardless of load order.
  • Do not pack assets in compressed BSAs as they are slower then uncompressed BSAs and in some cases cause bugs and even crashes with specific files. In BSArchPro, check marking files causes them to be compressed.
  • BSAs can hook to any ESP or ESM even if it's in a different mod folder.
  • For BSArchPro Autodetect Flags can be set instead of setting the flags individually like the guide instructs, it works most of the time but be aware it can at rare times fail causing frustration and forcing you to have to repack.

See Also