Collection of Data

As one would expect, an energy certificate can be prepared solely from the survey of the building. This would involve the creation of accurate plans, a survey of the fabric of the building, and the inspection of all the heating, lighting and ventilation equipment. For a large or complicated building this could become very time-consuming and expensive. In addition it is also possible that the rating and performance of some of the plant may not be gathered from inspection, or that various features of the building remain ‘unknown’. If a small proportion of data is unknown, a certificate can still be prepared using the assumptions and defaults given by the computer model. However, these assumptions and defaults are the poorest performance available for that item. Consequently, small number of unknowns may lead to a reduced energy rating.