The Royal Institute of Chartered Surveyors (RICS) regulate the delivery of RICS surveys by Building Surveyors. Where there is a Non RICS Report provided by a surveyor with a different qualification then these are things to note:
Cannot provide the RICS Report - only RICS surveyors can provide the HomeBuyer Report in the RICS format. Whilst a Non-RICS Surveyor can provide a similar service they cannot use the prescribed RICS Report format.
May not carry professional indemnity insurance - All RICS surveyors must carry in date professional indemnity insurance - they even have to keep paying this for 6 years after they retire.
Professional indemnity insurance can be called upon if the surveyor is negligent in the delivery of the service to you.
A Non-RICS surveyor may not carry such an insurance premium.