The smallest, simplest project in the whole program by panel and circuit count — an all-electric home whose real engineering content isn't the calculation itself, but the forward-looking capacity decision hiding behind it.
The project brief: a single-story, roughly 2,500 sq ft, 4-bedroom, all-electric single-family home — heat pump with backup electric heat, electric water heater, induction range, and a Level 2 EV charger — on a 200A, 120/240V single-phase utility service. This module walks the full NEC Article 220 Part IV (220.82) optional-method service load calculation with real numbers, the panel and circuit design that follows from it, the EV charger's dedicated 240V circuit and the load-management question, and the grounding electrode system.
It closes on the project's real design tension: the calculated demand clears the installed 200A service with only about 21% spare capacity — comfortable today, but thin enough that a single future load addition changes the right answer. The full worked calculation, panel schedule, bill of materials, and closing design reasoning are part of the unlocked module below.