| Value | Category |
|---|---|
| 1 | Strong material (galvanized iron, al, tile, concrete, brick, |
| 2 | Light material (cogon, nipa, anahaw) |
| 3 | Salvaged/makeshift materials |
| 4 | Mixed but predominantly strong materials |
| 5 | Mixed but predominantly light materials |
| 6 | Mixed but predominantly salvaged materials |