In pursuing low-carbon solutions in the construction sector, it is critically essential to unravel the intricate nexus between population aging and carbon emission efficiency (CEE). This research investigates this complex association utilizing provincial panel data from 2004 to 2020. Through the application of the super-efficient Slack-Based Measure and Malmquist–Luenberger (SBM-ML) model, the study quantifies the construction industry’s CEE, followed by using a fixed-effect model to assess population aging’s impact on CEE in the construction industry. Our study reveals a distinct “U”-shaped pattern, illustrating that population aging initially depresses but eventually amplifies CEE in the construction industry. We also observe marked regional disparities. For instance, the construction sectors in the eastern and northern regions show a rising trend, counteracting the initial decline in CEE due to aging. However, the central western and southern regions need more pronounced aging progression to experience comparable CEE improvement. These findings underscore the critical role of regional contexts and demographic transitions in shaping the CEE in the construction industry, providing valuable insights for crafting sustainable policies aiming at balanced population mobility and carbon neutrality.