Measuring for the width:

- Measure the window/door width, then multiply it by 1.5. You will get the total width you need for the curtains.
- Consider whether you wish one curtain panel or a pair to cover the window. Having 2 curtain panels is more common for standard cases.
- Example: the width 125 cm is for a not gathered panel. When fully gathered with S-fold tape the panel width becomes 84 cm.

For Thermal curtains to be effective, they must be installed properly.
- Thermal curtains should be installed as close to the window frame as possible. They are most effective when they drop to the windowsill or floor.
- Installing a cornice or valance above the drape further reduces the infiltration of air.