Once you have gotten plans on paper, and permits. And you are getting the foundation placed(or placing it yourself) make sure of all measurements, don't shrug a

Once you have gotten plans on paper, and permits. And you are getting the foundation placed(or placing it yourself) make sure of all measurements, don't shrug away half a degree off. Same with levelling the walls. This will save you a lot of cursing. Also if you are going with concrete then the electrics will be poured in, make sure you put a lifeline in for some circuits. (this is a connection from the entry point to a different point in the circuit than the connection you already have) This could save a lot of work if something goes awry and you lose a connection. insulation is good, but you don't want water condensation in between materials.