This book develops an intelligent, full-lifecycle cost control system for real estate projects operating under China's "dual-price-restricted housing" policy, where developers face government-capped sales prices alongside volatile, market-driven costs. Drawing on the case of LD Company's Lin'an high-tech dual-limited housing project, it traces cost governance from the decision-making and design stages through construction, settlement, and sales, integrating BIM modelling, IoT-based risk monitoring, and data-driven decision support. The author identifies key weaknesses in current practice — inconsistent investment standards, weak dynamic deviation correction, and fragmented data trails — and proposes a constraint-driven optimization framework combining predictive modelling, control-point identification, and feedback-based governance. Bridging theory and practice, the study offers real estate managers, cost engineers, policymakers, and researchers a concrete, technology-enabled model for balancing fixed revenue against uncontrollable costs.