Frankly the legal duties contained within the CDM Regulations (2015) apply to almost everyone involved in construction work.
You will need to :
1) sensibly plan the work so the risks involved are managed from start to finish
2) have the right people for the right job at the right time
cooperate and coordinate your work with others
3) have the right information about the risks and how they are being managed
4) communicate this information effectively to those who need to know
5) consult and engage with workers about the risks and how they are being managed
Chances are won’t need a health and safety consultant if you are confident and competent to deliver this role to the above standards.
But I’d have you consider the possibility that you will be spending time thinking about either the impacts of health and safety in your business.
Or maybe even losing valuable management time researching and looking for specific information on the topics that are affecting your business?