my @aBuildings;
while (my $line=<MYFILE>) {
  chomp $line;
  #... parse line

  # add a new element to your array of hashes (AoH)
  my $hLine = { 
     name => $bldg_name
     number => $vlan_number
     ...
  };
  push @aBuildings, $hLine;
}

##</code><code>##

  foreach my $hLine (sort { $a->{name} cmp $b->{name} } @aBuildings) {
    #print out contents of $hLine
  }