Client duties: (HSWA).
Do not create a risk to contractor (s3) and ensure H&S of own workers (s2).
Key actions to achieve:
1) select competent contractor (protects your staff)
2) Inform contractor of your special known hazards, especially ones they may not be familiar with.
3) Review own RA to check if conflict or additional measures needed by you, in your undertaking.
Contractor duties:
Ensure H&S of own workers (s2). Do not create a risk to others (eg client staff - s3) from your undertaking of being a builder, electrician, surveyor, window cleaner etc.
Key actions to achieve:
a) Fulfill all legal duties as employer - be competent, in essence
b) From client information, ensure adequate RCMs (via RA). Monitoring H&S compliance is also a key part of that.
Method statement may be simplest approach to combine a contractor RA with client's own site hazards / rules, but there is no legal requirement or standard.
Many large clients now seem to have a complete raft of their own rules, regardless of and beyond the legal requirements and then impose these on contractors. That means contractors just have to tick all the client boxes, and not take ownership of H&S decisions, even though they remain an employer. They will be told what to do and how to record it on what form. Hmmm.
If you run a library, the contractor brings all the risks to you - and you probably have to trust their expertise. So even if an electrician shows you a 'risk assessment' what are you going to do with it? A discussion and agreement on the safety aspects of 'interface' of contractor and staff / customers is the most practical and informative use of time. Minute it.
If you run an LPG plant, you own a significant yet hazardous asset, into which you are introducing an unaware builder or welder. You would want to take more of an interest, and dictate clear rules, otherwise the contractor, your staff, and possibly the public at large may be massively at risk.
So horses for courses. As this thread shows there are many practical systems and processes out there which can be adopted, but understanding the principles will make sense of these and what will work best for your company.
www.hse.gov.uk/pubns/indg368.pdf is a good starting point, at 7 pages.
HSG159 Managing contractors is a guide for small to medium companies in the chemical industry, but is also a good learning resource for anyone.
S2 duty is to ensure the HS&W of your employees.
S3 duty is not to create risk to others NOT your employees.