Had a representative from this company round earlier to measure up my property. ECO in this case stands for Energy Company Obligations
Apparently if someone living at the property is in receipt of benefits, and it's a poorly insulated property (grade E and below), there are fully funded grants available to add insulation, as well as upgrade the heating system and even fit PV. Seems the money is raised from the green levy in your energy bill, so that particular pot must be quite full at th