In Ireland, a BER certificate is generally valid for up to 10 years from its issue date, provided no significant changes are made to the home that affect its energy performance. An extension, major renovation, or replacement of heating or ventilation systems may mean a new assessment is appropriate. If the certificate has expired, a new BER assessment is normally needed before selling or letting the property. A registered BER assessor can confirm what applies to your home, and you can check certificate details through the official SEAI website.