Monteiro, DélcioSoares, Orlando2026-05-062026-05-062025Monteiro, Délcio; Soares, Orlando (2025). Energy efficiency assessment of a youth hostel based on multizone modeling and simulation. In IX Congresso Ibero-Americano de Empreendedorismo, Energia, Ambiente e Tecnologia (CIEEMAT 2025). Portalegre, Portugal. ISBN 978-989-8806-89-5978-989-8806-89-5http://hdl.handle.net/10198/36563This paper presents an energy performance assessment of a youth hostel in northern Portugal through multizone dynamic simulation. The study combines on-site data collection, energy billing analysis, and advanced building modeling in DesignBuilder using EnergyPlus as the calculation engine. The model includes the building envelope, occupancy profiles, internal loads, HVAC systems, lighting schedules, and domestic hot water production. The simulation results reveal that heating demand is strongly concentrated on the ground floor, with a total installed capacity of 51.04 kW after applying the required safety factor. Lighting contributes minimally to internal gains due to the exclusive use of efficient LED fixtures with occupancy sensors. Annual CO₂ emissions were estimated at 84.21 tonnes, highlighting the building’s environmental impact. The results demonstrate the relevance of dynamic simulation as a decision-support tool for optimizing energy performance, reducing operational costs, and prioritizing future retrofit measures in similar hospitality buildings.engconference object