Updated: 31 July 2025

Terrain Category 3

Overview

Terrain Category 3 (TC 3) describes terrain with numerous, closely spaced obstructions. It is typically found in dense residential or industrial areas, or forests.

Why This Is Important

  • Ensures buildings are engineered for lower wind speeds due to obstruction shielding.
  • Commonly used in suburban and light industrial construction zones.
  • Helps prevent over-engineering or under-engineering structural elements based on environment.

Characteristics

  • Obstruction heights typically range from 3 to 10 meters
  • Minimum density: equivalent to 10 house-size obstructions per hectare

Examples

  • Suburban housing
  • Light industrial estates
  • Dense forests

Tips, Best Practices & Troubleshooting

  • If you're unsure whether to classify as TC 2.5 or TC 3, check the number of houses, trees, or obstructions per hectare.
  • For mixed developments, use the most conservative classification or seek engineering support.
  • Consider all directions of exposure (wind sectors), not just what's visible in front of the building site.

Terrain Category 1

Terrain Category 2

Terrain Category 2.5

Site Specific Engineering

Request Engineering (Site Check)

Review & Updates

Version History:

  • v1.0 – 18 March 2019
  • v2.0 – 31 July 2025

Article Information

  • Category: Engineering & Site Specifications
  • Target Audience: Estimators, Sales Coordinators, Franchise Users
  • Business Owner: 
  • Version: v2.0
  • Last Reviewed: 31 July 2025