Climate-________ buildings are independent of the external environment.

The term that best completes the phrase is "rejecting," leading to the concept of climate-rejecting buildings, which are designed to operate independently of the external climatic conditions. This approach emphasizes creating a built environment that minimizes reliance on external weather conditions, such as temperature, humidity, or sunlight, allowing the building to maintain a comfortable internal environment without needing to adapt to or respond to these external factors.

This can involve the use of advanced materials and technologies that create an isolated space. For instance, buildings may employ high-performance insulation, reflective surfaces, or even mechanical systems that actively manage the internal climate without drawing on the natural climate systems around them.

Other options, though relevant to various architectural practices, do not convey the same independence from the external environment. "Adapting" implies a reaction to environmental changes, "responsive" suggests a building that changes based on external conditions, and "efficient" refers to reducing energy consumption but does not necessarily imply independence from the climate. Thus, "rejecting" accurately characterizes buildings designed to be self-sufficient in terms of climate control.