In homes which have fireplaces or fire pits, there is a necessity for a shed around the house to store the firewood. Building a firewood shed is not very difficult, all you need is a plan and some raw material. Building a firewood shed involves only basic post and beam carpentry. Building a shed to store your firewood will help keep the wood from getting mushy and also ensure that it remains free of rodents. A firewood shed is a long term investment the idea being that you get wood in the spring when it is wet and green, leave it to dry out and season until you use it the next winter.