What is the maximum height of the side firewall for R-4 zoned properties with a firewall on the rear?

The maximum height of the side firewall for R-4 zoned properties with a firewall on the rear is typically established based on specific zoning regulations and building codes. In this case, the answer indicating 3 storeys aligns with commonly adopted building laws that aim to manage fire safety and structural integrity in residential zones. The intent behind having restrictions on the height of side firewalls is to ensure adequate light and air access for adjoining properties while also controlling how fire risks may spread between structures.

The designation of 3 storeys serves as a balance between allowing sufficient building height for practical residential development and maintaining safety standards that protect the surrounding environment and inhabitants. As buildings increase in height, the potential risks associated with fires also scale up, which justifies why a limit is set. This understanding reinforces compliance with fire safety measures and contributes to orderly urban planning.

In contrast, higher options such as 4 or 5 storeys would contradict the intent of zoning regulations aimed at safeguarding residential areas from increased hazards associated with larger structures. Therefore, the specified height of 3 storeys effectively encapsulates zoning intent and safety protocols, making it the correct answer.