EIM71312 - Tax treatment of working rule agreements: site-based staff employees: definition
The term site-based staff employees means staff employees in the construction and allied industries (that is the building, civil engineering and other closely related industries where working rule agreements have been negotiated) who work alongside operatives in those industries and on a broadly similar basis.
Such employees (including, for example, site agents, supervisors and clerical and professional staff) are normally attached to a particular construction site for the duration of their employer’s contract there, after which they move on to start work at a new site. They may spend a few months or several years working at each construction site, and do not normally work elsewhere.
The staff involved may be recruited from the employer’s headquarters and have their work organised and controlled from there, but they rarely attend those premises (except, perhaps, to report progress or to obtain instructions), and do not normally exercise their skills there.