The building documents are available in a number of compressed archive forms:
-----------------------------------------------------------------------------
building.tar.Z  -  info for builders in .tar.Z format   (UNIX 16 bit compress)
building.tar.gz -  info for builders in .tar.gz format  (GNU gzip)
building.zip    -  info for builders in .zip format     (ZIP/PKZIP)

Pick the one of your choice:
----------------------------
.tar is handled by the program tar                   (common under all UNIX's)
.Z   is handled by the program uncompress            (common under all UNIX's)
.gz  is handled by the program gzip                  (common under most UNIX's)
.zip is handled by the program unzip, or pkunzip.exe (common under MSDOS)

Common methods of decompression:
--------------------------------

For building.tar.gz:
--------------------
zcat building.tar | tar xvvfp -
      or
gzcat building.tar | tar xvvfp -
      or
tar -xzf building.tar.gz
      or
gzip -d building.tar.gz; tar -xf building.tar

For building.tar.Z:
-------------------
tar -xZf building.tar.Z
      or
uncompress building.tar.Z ; tar -xf building.tar

For building.zip:
-----------------
unzip building
      or
pkunzip building