Core Viewpoint - The article discusses the innovative approaches taken by Hangzhou's Qianjiang New City to retrofit old buildings for energy efficiency and carbon reduction, particularly in the context of the National Low Carbon Day [1][2]. Group 1: Low Carbon Building Management - The Qianjiang New City has developed a new management path for "low carbon buildings" by promoting smart lighting and introducing energy management systems, leading to significant energy savings and carbon reduction [1][2]. - The focus is on optimizing the management and retrofitting of older buildings, which were constructed around 2001-2002, to address their high energy consumption issues [2][3]. Group 2: Implementation of Standards - The district has drafted and published low carbon building standards to guide buildings in improving their low carbon operational management levels [2][7]. - The standards evaluate buildings based on energy recovery, clean energy use, and other metrics such as rooftop solar panels and rainwater recovery systems [7][8]. Group 3: Practical Examples and Benefits - Successful examples include the Taiping Financial Building, which reduced electricity consumption through time-zone lighting and installed solar panels that can recoup costs within five years [8]. - The initiative aims to create a win-win situation for businesses by reducing costs and contributing to societal energy savings and carbon reduction [8][9]. Group 4: Broader Community Impact - The low carbon building initiative is part of a larger effort to create a "low carbon community," which includes ecological experiences, economic model exploration, and environmental improvements [9]. - Activities such as ecological concerts and waste recycling initiatives are designed to foster a culture of low carbon living among residents and office workers [9].