This app is a complete residential electrical engineering platform for single-family house design, built around NEC 2023 compliance. It combines an interactive 17-phase design workflow with a 30-drawing engineering gallery and three fully functional NEC engineering calculators. INTERACTIVE NEC CALCULATORS NEC Load Calculator (Article 220 Standard Method) Enter floor area, appliance loads, HVAC, EV chargers, and solar PV backfeed. This app applies NEC demand factors from Table 220.42, dryer minimums per Section 220.54, range demand from Table 220.55, and fixed-appliance factors per Section 220.53 to compute total demand load and recommend the correct service size (100A through 600A). Voltage Drop Calculator (NEC 210.19 / 215.2) Select copper or aluminum conductor, choose single-phase or branch circuit, pick conductor size from #14 AWG to 500 kcmil, then enter load current and one-way run length. This app calculates voltage drop using the circular-mil formula (VD = 2KIL/CM) and instantly shows pass/fail status against NEC 3% branch and 5% combined targets. NEC Code Quiz 20 multiple-choice questions covering NEC 2023 residential requirements: receptacle spacing (Section 210.52), AFCI protection (Section 210.12), GFCI locations (Section 210.8), service sizing (Section 230.79), grounding electrode systems (Section 250.52), load calculations, conductor ratings, and more. Detailed explanations appear after each answer. 17-PHASE ENGINEERING WORKFLOW Step-by-step workflow from site assessment through system commissioning, covering permit applications, load calculations, panel design, grounding systems, branch circuit layout, AFCI and GFCI coordination, and final inspection. 30-DRAWING ENGINEERING GALLERY Full design package including service entrance one-lines, panel schedules, grounding electrode diagrams, branch circuit layouts, receptacle and device plans, load calculation worksheets, conduit routing diagrams, and project-specific details. PHASE DELIVERABLES TRACKER Track completion status across all 17 design phases with a built-in deliverables checklist. NEC 2023 DESIGN GUIDE Comprehensive reference covering NEC Articles 100, 200, 210, 220, 230, 240, 250, 310, 406, and 440 as applied to single-family residential projects. DISCLAIMER This app is intended as an educational reference and design aid for licensed electrical engineers, electricians, inspectors, and students. All calculations and content are based on the 2023 National Electrical Code published by NFPA. Actual designs must be reviewed and stamped by a licensed professional engineer registered in the jurisdiction of the project. Local amendments to the NEC may apply. The developer assumes no liability for designs prepared using this app. Always verify compliance with the authority having jurisdiction (AHJ) before construction.