Ontario Building Code Practice Exam 2026 - Free Building Code Practice Questions and Study Guide

The minimum height required for a guardrail on a balcony in a residential building is 1100 mm. This height is determined by building safety regulations and is meant to prevent falls and injuries. Option A and B (900 mm and 1000 mm) are too low and do not provide enough protection. Option D (1200 mm) is higher than the required minimum height and could be more expensive to install. Therefore, option C (1100 mm) is the best choice as it meets the minimum height requirement and does not exceed it.