This chapter provides an overview of a general design approach for electrical distribution systems of residential and commercial buildings. As noted throughout this chapter, safety is the main objective when designing building distribution systems. The relevant codes and standards that assist in designing safe electrical systems are outlined. In addition to safety, other objectives should be considered when specifying building electrical systems, as discussed in this chapter. In particular, building power distribution systems should be designed to be reliable, flexible, accessible, and energy efficient. Moreover, typical design phases for building projects as well as the main roles of the architectural engineering design team members are briefly presented.