This depends upon the complexity of the job. We don't have a set hourly rate, since we prefer to calculate fixed price fees according to the resources needed on a project.
Top rates tend to apply to giving evidence in Court.
Overall, our fees are roughly the same as a provincial Solicitor, and you should probably think in terms of 600 per day. Long term contracts attract lower fees. These buildings are normally air conditioned. SBS is not normally just due to temperature and air quality - social and management factors frequently interact as well. Don't be conned into counting colonies of bugs in ducts.