You can get better exp with oak plank if you know what to build. You can get an extra 7.5xp per oak plank if you have the red cw armour, 15xp per oak plank if you have the silver cw armour and 22.5xp extra if you have the gold one. (just need shield, helmet and plate) It only needs 28 construction and you get the armour back every time you remove the armour set. I know the bricks would still be cheaper exp, but this is faster :P.