You need to get up to speed pal .Of course the individual sites will have different needs but health and safety applies to everyone,its just tailored to needs , from the tea boy to managing director and liability if proven will reach from the top downwards .Private land is no different .If theres a serious accident HSE will be informed and action can be taken on anyone acting carelessly whoever they are .This is why we cant beat burglars ,why your dog cannot bite the postman and why i spend so f***ing long in the office writing up reports to change a f***ing light bulb and why new builds cost