Question: Our question relates to the safety responsibility and liability our business has for subcontractors of a nominated contractor. The scenario is:

• Our business – Controller of premises
• Contractor A – Principal contractor (mechanical services company)
• Contractor B – Subcontractors (electrical company or sole trader)

Our business engages Contractor A to undertake repairs and maintenance to the air conditioning system on our premises. Contractor A requires Contractor B to do some electrical work on the air conditioning system. Our business collects insurances from Contractor A, but does not collect insurances from Contractor B.

Our questions are as follows:

1. Does our business need to conduct due diligence for all subcontractors engaged by the principal contractor to perform work on our site?

2. Is our business required to check that Contractor B has relevant insurances and qualifications, or is a written agreement necessary between our business and Contractor A outlining Contractor A’s responsibility to ensure Contractor B is covered by insurances and is suitably qualified?

3. Does a written agreement need to be in place to ratify the responsibility for the principal contractor to be conducting their own due diligence in relation to the subcontractors engaged by them?