I assume the following properties have the following amount of possibilities:
- HALF: 3 possibilities (lower, middle and upper)
- FACING: 4 possibilities (north, south, east, west)
- OPEN: 2 possibilities (open or closed)
This makes for a total of 3x4x2=24 possibilities you can have. Now, metadata can only have 16 different values (0-15), which is not enough to store the 24 possibilities you have. You probably want to use a
TileEntity
for your blocks.