All schools will no doubt have teacher code of conducts, but what about safeguarding procedures for contractors on site and visiting adults? Its a gap that's often left, and excellent schools will have covered this professionally.
First, when someone walks through the door of the school, is there a clear banner outlining key messages and expectations of guests? This is cheap and easy to do. You can also have a small booklet which covers expectations of wearing ID, what to do in a fire and something about safeguarding on it. It is important for all adults on site to know they can only use adult toilets, must not take photos, and know who to see in case of safeguarding issues. A sample of one is enclosed on this blog so you can adapt and make one of your own.
The other key area is contractors on site. Contractors should meet briefly with the Safeguarding Officer once they are on site to go over the booklet given out above, and to have a short briefing about not talking with pupils and key messages. For contractors likely to be on site for longer periods, the Safeguarding Lead can go over a Code of Conduct such as the example enclosed. Of course, no system is every foolproof, but at least you can say expectations were clear and understood and that you did your very best to cover all bases.
Parents visiting can be given the leaflet about expectations but also a sheet about care and support offered at the school. This can be tremendously reassuring and again makes it clear what you as a school stand for.
Last, but by no means least, you may have a teacher code of conduct, but does this cover all adults on site? Many schools are now moving towards all staff codes of conduct which cover all adults on site in addition to your Safeguarding Policy. This can be gone over at your safeguarding training which all adults on site should attend. Again, this just makes sure that everyone on site has had clear briefings and has had clear and effective training and notes to refer to. There is an example enclosed of a whole staff code of conduct which I hope is useful food for thought!