What are the necessary Fall Arrest Equipment for a building site? This depends on the height of the work and the experience of the worker, however safety should never be underestimated. Here are some example UK Tool Supply has for staying safe on site. 

Tool Belt Hooks are attachment to a lanyard or a belt buckle which allow you to bring your tools up a harness safely.

Fall Arrest Harnesses are attachments that are normally associated with pull rope and situation where construction at high levels may need to be done.