Temperature and Moisture Control. If your workshop is to be located in a portion of your house that is already comfortably warm, this will not be an issue. But if you’re converting a barn or shed or an unheated space, especially if you live in a climate where winter temperatures make for cold hands, you’ll need to devise a heating strategy. In some climates, air conditioning is a virtual necessity in hot weather.
Let’s be clear about one thing: No workshop is perfect for everyone. If there were, I could simply give you a precise plan to follow with clear dimensions. Every person who comes to the hobby, avocation, or profession of woodworking has his own particular collection of tools and his own peculiar work style, skills, and desires for the kind of woodworking he wants to do that gives him a unique approach as to how he will lay out a shop: where the tools should go, where lumber and supplies are stored, and how much bench area he needs.