The Economic Benefit Evaluation of Elevator Retrofitting: An Empirical Analysis of Second-Hand Housing Price Premiums in Hangzhou’s Older Residential Compounds

Against the backdrop of urban renewal and population ageing in China, elevator retrofitting in older residential compounds has emerged as a critical yet contentious issue, primarily due to uneven cost-sharing and perceived inequities in the distribution of benefits. This study employs a combined empirical framework integrating Difference-in-Differences (DID) and cost–benefit analysis to systematically evaluate the economic impacts of elevator installation in older neighbourhoods of Hangzhou. Using transaction data from 879 housing units across 18 residential compounds between 2018 and 2020, along with actual project cost records, we quantify the premium effects and assess economic feasibility. The results show that elevator retrofitting leads to an overall 5.53% increase in housing prices, with significant vertical differentiation: upper-floor units appreciate by 8.10%, middle-floor units by 4.58%, and lower-floor units by 1.59%. Further analysis confirms that the aggregate increase in property value fully covers installation costs, long-term maintenance, and reasonable compensation for lower-floor residents, thereby achieving a Pareto improvement. The study establishes a floor-gradient linkage mechanism between value uplift and cost-sharing, providing a quantifiable basis for policy design and community negotiation. These findings challenge the prevailing zero-sum view of elevator retrofitting while offering a replicable model for urban renewal that equitably balances stakeholder benefits.