The cost of a BER assessment varies by property size, location, and the registered BER assessor, so it is worth requesting a quote in advance. You may be asked for building plans, insulation details, window specifications, heating and hot-water information, and details of any renewable technologies such as solar PV. Your assessor will inspect the home and may make reasonable assumptions where records are unavailable, which can affect the assessment. Ask your assessor what documents they require, and check the official SEAI register for a registered assessor.