Once you have reviewed the qualifying criteria and you’ve have had your system designed you can submit your system design to the ECA scheme who can confirm if it complies with the ETCL criteria for component AMT systems. If you design complies DECC will issues you with a DECC Certificate of Energy Efficiency which you will need to make your claim. If you change your design during installation your current certificate will be invalidated and the redesigned system will have to be reviewed separately for compliance with the criteria. You can alternatively submit your system design to the ECA Scheme after you have installed your system.