Simple blocks – e.g. no TileEntity and no metadata – are supported out of the box with the blueprint mechanism. As soon as you have metadata supporting anything more fancy than the block kind, e.g. for orientation, or extra data that has to be stored in tiles, you’ll need to implement a instance of the class BptBlock from the BuildCraft API. It should be pretty well documented, and you can find implementation examples for Minecraft vanilla blocks in the package api.bptblocks. But don’t hesitate to post on the forum if you need more information or features!