This working document provides an operational handbook mainly for Level B KPIs focused on data-driven energy management and operational decarbonisation in municipal buildings and public space. It translates monitoring into action by defining actionable indicators, alert rules, thresholds, intervention recipes, ticketing logic and minimum instrumentation requirements. The handbook focuses on robust operational KPIs for heterogeneous city and multiple parameters and indicators. It also proposes minimum technical requirements for monitoring systems, data quality, interoperability, cybersecurity, privacy and gradual integration of buildings, urban-lighting+water and public-space systems. This version is deposited as a technical working document to establish authorship, version traceability and a shared operational basis for discussion and future implementation within the URBANEW EMC³ framework. It does not constitute a formally approved institutional document. Libro operativo de indicadores KPI – Nivel B: reglas, umbrales, alertas y operación para la descarbonización basada en datos.