This paper investigates optimal configurations for multi-vector energy systems, with a focus on low-temperature district heating networks (DHNs) powered by shallow geothermal energy. The system takes into account natural ground regeneration during heat extraction, which prevents borehole freezing and maintains efficiency. The study examines the balance between centralized and decentralized heat production while ensuring fair thermal energy distribution among buildings. The DHN model accounts for heat losses and inter-building distances, with a piecewise linear method used to represent pipe costs. The optimization framework evaluates both building-scale and district-scale solutions, considering various technologies, ground constraints, and temperature levels. The Renewable Energy Hub Optimizer (REHO) is employed as a basis to determine the optimal design and operation of these energy systems [7]. The case study focuses on a building stock in Belgium, incorporating building-level demands for space heating and electricity.