AS/NZS 1170.1 Imposed Action Selector – Table 3.1

The AS/NZS 1170.1 Imposed Action Selector is an easy-to-use online reference tool designed to help structural engineers, civil engineers, designers, students and construction professionals quickly identify appropriate imposed actions for floors and occupied areas in accordance with AS/NZS 1170.1:2002 – Structural Design Actions, Part 1: Permanent, Imposed and Other Actions.

In structural engineering, imposed actions are loads that arise from the intended use and occupancy of a building or structure. They are also commonly referred to as live loads. Unlike permanent actions, imposed actions can vary during the life of a structure as people, furniture, equipment, stored materials and vehicles move or change. Selecting an appropriate imposed action is therefore an important part of structural design.

This online selector provides convenient access to commonly used imposed-action values from Table 3.1 of AS/NZS 1170.1. Simply select the relevant occupancy or use of the area to view the corresponding uniformly distributed action in kPa and concentrated action in kN. AS 1170_01

The selector covers a wide range of common building uses, including residential buildings, apartments, offices, hotels, hospital areas, classrooms, laboratories, restaurants, commercial kitchens, corridors, stairs, assembly areas, auditoriums, gyms, shops, storage areas, plant rooms, car parks and vehicle-access areas. The categories follow the activity and occupancy classifications used in AS/NZS 1170.1, making it easier to identify the appropriate design value for a particular floor area.

For example, an office for general use is classified under Category B and has a reference uniformly distributed imposed action of 3.0 kPa and a concentrated action of 2.7 kN. Other occupancies may require significantly higher actions depending on their intended use, crowd activity, storage requirements or vehicle access. AS 1170_01

The distributed and concentrated actions should not simply be added together. AS/NZS 1170.1 requires them to be considered separately and positioned or applied as appropriate to determine the most adverse effect on the structural element being designed. AS 1170_01

This tool is intended as a quick structural engineering reference and does not replace engineering judgement or the complete requirements of AS/NZS 1170.1. Designers should always verify the selected occupancy classification, applicable notes, load reductions, load combinations and project-specific requirements before completing the final structural design.