This is called an Occupancy Assessment and a Green Deal Advice report is required for some funding programmes, such as the Feed in Tariff (FIT) Energy Company Obligation (ECO and the Renewable Heating Incentive (RHI)
There are certain circumstances when the RdSAP methodology is not appropriate; in the case of new builds, conversions from commercial to residential property, Public buildings and commercial properties. This is not an exhaustive list.
Do some investigation before you book with any training company! Make sure you ask these questions. Not all companies offer the same package.