Evaluating building egress safety for the elderly under different urgent-level circumstances in high-density cities: Based on ABEM-enabled simulation

In high-density cities, people usually live in mid-rise or high-rise residential buildings where indoor environments are quite complicated. Safety risks exist not only within homes, but also on the way to egress from residential buildings. As the aging issue becomes severer, it is essential to provide safe egress plans particularly for the elderly who are more fragile to risks and obstacles. Kinds of emergencies might occur in reality, some are hard to predict and extremely dangerous, while some can be warned in advance and would not cause damages immediately. However, previous research seldom considered the different urgent levels of circumstances during the egress process of the elderly. Consequently, this study contributes to proposing an agent-based egress model (ABEM)-based evaluation of building egress safety for the elderly under different urgent-level circumstances by introducing absolute and relative indicators. Absolute indicators evaluate building egress safety for the elderly, relative indicators reveal whether buildings hinder safe egress of the elderly compared with ordinary residents, and indicator weights are decided by AHP method to compute building egress safety index (BESI) as the evaluation results. Case study shows BESI scores of 8.696, 8.941 and 6.290 under three circumstances. BESI scores are valuable references for old home buyers to make decisions. Furthermore, this evaluation approach offers an effective tool to help designers to improve design schemes for safer egress, to assist property managers in updating egress plans and facilities based on new occupancy status in the operation stage, eventually to facilitate the development of healthy residential buildings.