Carbon-neutral buildings eliminate fossil fuel combustion, adopt nature-based passive and green design strategies, and ensure zero-carbon electricity and heat supply. This special issue examines China’s building sector and proposes an ecological transformation pathway toward carbon neutrality. End-use energy demand is first minimized through sufficiency and efficiency measures. On the electricity side, building surfaces are utilized for distributed photovoltaics, integrated with electric vehicle batteries, enabling demand-side coordination with the power grid via photovoltaic–energy storage–direct current–flexibility (PEDF) systems. On the heating side, zero-carbon supply is achieved through natural-source heat pumps and surplus-heat sharing systems with thermal storage. Future buildings will evolve from energy consumers into prosumers and system regulators, representing a fundamental shift in the carbon-neutral transition.