What are U-values?

What is a U-value?

A U-value is the measure of the rate of transfer of heat. This is not the same as an R-value which is the measure of how resistant a material is to the transfer of heat.


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A U-value is measured in W/m^2K – Watt/(Metre squared)(Kelvin).

A U-value is the reciprocal of the corresponding R-value. If the R-value is 2, the U-value will be 1/2 or 0.5. If the R-value is 5, the U-value will be 1/5 or 0.2.

The higher the R-value is the lower the U-value is. This confirms the relationship between R-values and U-values. If the material is more resistant to the transfer of heat (high R-value), it will transfer heat as a lower rate (low U-value).

There is no need to focus on both U-values and R-values as they go hand in hand. If you focus on increasing the R-value of insulation materials in your home you are guaranteed to have a decreased U-value.

Why are U-values important?

Building regulations for Government grants require that U-values for houses must not exceed the following;

       Roof   0.4 W m-2 K-1
       Walls 1.1 W m-2 K-1
       Floor  0.6 W m-2 K-1

SEAI Grants

You could receive up to €4500 – not bad, right?

These grants are only available on homes built before 2006, and you must use an SEAI registered contractor for all works. Luckily, we are an SEAI registered contractor. We even provide a nationwide service.

You can find more about SEAI grants here.

If you would like to find out more about the grants available with the Better Energy Homes Scheme feel free to contact us on 1800 911500, or by email at info@myfoam.ie. We also have a contact form available on our home page. Our excellent team provide professional guidance from the outset and throughout.

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