What is included in the perimeter measurement of a home?

The perimeter measurement of a home encompasses the entirety of the external dimensions that define the building's footprint. This includes features like cantilevered floors and chimney bump-outs, which extend beyond the main walls of the structure. Such architectural elements are integral because they can affect both the overall square footage of the home and its energy performance.

For instance, cantilevered floors can provide extra usable space without extending the foundation, and chimney bump-outs can affect airflow and heat retention, both of which are critical factors in energy assessments. Evaluating these elements in the perimeter measurement ensures that all aspects of the home's design are considered when assessing energy efficiency.

The other options focus on narrower aspects of the home or do not account for the full exterior layout. Only considering the foundation disregards important above-ground structures, while measuring just the interior walls misses elements that extend outside the typical boundaries of the home. Similarly, while garden windows and balconies can contribute to a home's aesthetics and outdoor space, they might not be part of the primary external footprint in the same way as cantilevered features or bump-outs are.