What’s the difference between ‘R-values’ and ‘U-values’?

‘R-values’ and ‘U-values’ are measurements used to judge the effectiveness of different types of insulation. They are the insulation equivalent of the energy stars on washing machines and fridges.

The R value measures the ability of your insulation material to resist the flow of heat.

The ‘U-value’ helps you to judge the effectiveness of window insulation. It’s the measure of how much heat can be transferred through the window.

When it comes to installing insulation or windows:

• with insulation go for the highest ‘R’ rating
• with windows go for the lowest ‘U’ rating.

If in doubt, consult your local insulation and window expert.