The idea has already been introduced in the Australian Capital Territory, the UK and EU countries. Labour said it planned to first introduce the requirement on homes for sale. Casimir MacGregor, a senior scientist at building research institute BRANZ, said the overseas certificates typically require an inspector to visually assess the home’s features, such as the insulation and windows. This results in a short report and a letter grading of the home’s energy efficiency, plus tips for improvements. Most schemes use an A (very efficient) to G (very poor) rating scale, MacGregor said. Some schemes also translate the energy usage into a carbon footprint.