When the Assessor arrives at your home they will conduct a non intrusive survey. A BER assessment will typically take a couple of hours to complete (depending of course on the home size and complexity). The Assessor will need to have access to all the rooms in your home.During the survey they will be measuring the area of the rooms, measuring the windows, the thickness of the walls, the levels of insulation, the heating system, the number of flues, the floor types and the wall types. The Assessor will typically collect 80 pieces of data which describe your home, which are then entered by the Assessor into the BER software tool in order to generate the BER.