A DECISION-SUPPORT TOOL FOR LIFE CYCLE ASSESSMENT OF DISTRICT HEATING NETWORKS IN HISTORIC URBAN CONTEXTS: THE BRESCIA CASE STUDY

District Heating and Cooling Networks represent a fundamental solution for advancing urban decarbonization, aligning with the European Union’s Long-Term Strategy. These centralized infrastructures significantly enhance energy efficiency and contribute to emissions reduction. However, their deployment is often hindered by complex regulatory frameworks, particularly in historic urban centers in Italy, where modernization efforts must be reconciled with stringent heritage preservation requirements. This study underscores the necessity of a standardized methodological framework for assessing the environmental performance of District Heating and Cooling Networks. Existing life cycle assessment methodologies are predominantly tailored to specific case studies, limiting their broader applicability. To address this gap, this research develops a flexible and replicable assessment tool designed to be applied across diverse urban contexts. A case study examines the potential integration of a historic district in Brescia into the existing District Heating and Cooling infrastructure, comparing this scenario with conventional heating solutions, primarily a natural gas boiler, under a projected future scenario characterized by increased decarbonization of the energy vectors from national grid distribution. The reference buildings and their energy performance were modeled according to CENED database to ensure analytical robustness. The study employs an advanced decision-support framework based on life cycle assessment principles, conforming to the EN 15804:2019 standard. A cradle-to-cradle approach quantifies environmental impacts across all system components through validated empirical equations. The Environmental Footprint 3.1 methodology, supported by emission factors from the ecoinvent 3.10 database, ensures methodological consistency. Furthermore, an attributional life cycle assessment approach evaluates the multifunctionality of the District Heating and Cooling system following the allocation procedures established by EN 15316:2018, demonstrating that the choice of allocation method significantly influences the resulting climate impact profile. Based on the outcomes of this case study, the authors emphasize the need to incorporate substitution-based criteria to evaluate environmental trade-offs. When integrated with a consequential life cycle assessment approach, this methodological combination provides a more comprehensive assessment framework, yielding deeper insights into the broader environmental implications of District Heating and Cooling Networks.