You'll need to produce 2100 bricks to unlock the achievement. For most of the game the Pottery, where the bricks are created, will also need to be used in order to make glass bottles and crockery which are both tied to their own achievements. If you are going for the completion this one will be very near the end of the game. My progress at the time of writing this guide is only 773 out of 2100 and I've unlocked all level related achievements and am now solely focused on the crafting achievements. Bricks only use logs and clay to be created but they need two of each resource in order to make a single brick and each brick has a long production time. A level 50 character still takes about 25 minutes to make a single brick.