Construction classifications are based on which two factors?

The correct answer, which focuses on the materials used and hourly fire-resistance ratings, reflects the core criteria established by building codes and standards. In construction classifications, understanding the materials used is essential because different materials possess varying fire-resistance capabilities, influencing how structures react in fire conditions.

Hourly fire-resistance ratings are critical as they provide specific benchmarks for how long a material or assembly can withstand fire exposure before failing. This information is pertinent for ensuring safety, as it helps determine the appropriate building requirements to protect occupants and property during a fire incident.

In terms of compliance with safety regulations, fire-resistance ratings guide building officials, architects, and engineers in selecting materials that will optimize safety standards and determine appropriate construction practices. By focusing on these two factors, the classification system aims to enhance fire safety in buildings, which is a priority in urban planning and public safety policy.