Honeycomb blinds (also known as cellular blinds) are the most energy-efficient options.
These blinds are so effective because each ‘honeycomb’ in the blind is able to trap still air. Because air is such a good insulator, this means less heat escapes from your home in winter. These blinds also come with aluminium foil backing, making them a good option for keeping your home cool in summer too.
Other blinds that are effective include roman and roller blinds.
Though venetian blinds have become popular, they do very little to make your windows more energy-efficient.