Describes how the phius 2021 CORE Prescriptive standard achieves passive house performance for single family homes without requiring full energy modeling. Covers the rules by which the contributing factors to heating and cooling loads are regulated individually - heat transmission, ventilation and infiltration, solar gains. Also covers the scope limitations, zero-energy-ready and electrification readiness, provisions to limit moisture risk, and requirements on the efficiency of mechanical equipment and appliances to limit overall energy use. A dynamic checklist provides calculation support for some tradeoff calculations. An online calculator gives a snapshot of the requirements that vary by climate and building size.