Toward urban decarbonization: environmental and financial evaluation of neighborhood-scale multifamily retrofit strategies

Urban-scale residential retrofits are critical for reducing energy demand and advancing city-level decarbonization; however, financial and logistical barriers often limit their adoption. In this regard, this study examines the environmental and financial performance of three retrofit scenarios: high-efficiency heat pumps (HP), heat pump water heater (HPWH), and rooftop photovoltaic (PV) systems, in multifamily buildings at the neighbourhood scale, in Austin, Texas.

The study employs Urban Building Energy Modelling (UBEM) and Life Cycle Cost Analysis (LCCA) to model energy consumption, CO₂ emissions, and cost-effectiveness for each retrofit scenario. The simulation results show acceptable payback periods (PBP) of approximately 9.1 years for HP, 2.8 years for HPWTs, and 4.1 years for the PV scenario. The results also show how financial incentives such as local rebates, federal tax credits, and bulk discounts reduce upfront costs substantially and lessen economic barriers to implementation.

The findings underscore the potential of integrated, neighbourhood-scale retrofits as effective tools for meeting municipal climate goals and advancing urban energy equity.