After speaking with the client, and establishing a solid brief, the hazards can be identified.
The hazards that exist in a current building should not exist in a new building, and considering them at this stage is the only way the achieve that. Each task will have its own very special set of requirements, along with the requirements of the people performing those tasks, and using the building. Hazards can commonly be designed into a building by not understanding them. The only way to understand them is with ergonomics.
The brief should provide enough information about the tasks, and industry, and if the client has a current workplace then they are a very helpful resource at this stage. Being able to view the current workplace and identify current hazards can help avoid the same ones covered in a new coat of paint.
Also reviewing relevant records, and documentation can highlight any issues currently experienced. Their are common hazards experienced across industries, so it also helps to contact similar industries, especially if the building is for a completely new workplace with no records to review.
A list of potential hazards will be developed, and then the process of assessment and research to avoid them can begin.