Hi - just noticed your post & saw that you're paying an HR Co to draw up a contract for you. I'm ex-HR & just wanted to ensure you're not getting ripped off - the reason being is I don't actually see this type of agreement as an 'employment contract' (an therefore coming under employee legislation) as the self-employed are EXACTLY that - self employed. Other than H&S legislation you are not responsible for anything to do with their employment.
What you do need is a rental type agreement (contract). I'm looking into this myself at the moment & what I'm fairly sure you legally need to include is:
Address of rental space
Length of terms of lease (6mth, 1 yr etc)
Availability (mon-fri etc)
Notice period (both parties)
Monthly/weekly/annual rental cost
Period of payment (weekly, monthly etc)
Inclusions (tea/coffee, products, receptionist, waste, electric etc)
You can also include things like, review periods, exclusions on use of certain facilities, non set up within a certain radius on leaving etc etc etc)
I've attached a document designed for renting a chair in a hair salon but principle is exactly the same. It looks a bit daunting but can be simplified and put in less legal jargon! Lol
http://www.nhf.info/documents/chair-leaseholder/1chair-leaseholder.pdf
HTH
Debbs x