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What U-value should I target when insulating an existing roof?

Chris Brookman
Member Admin

For existing domestic roof structures that are being refurbished, you should target a U-value of 0.18 W/m2K as a maximum. You can go lower if you wish but unless you’re insulating your walls as well it is probably not necessary.

To see what we’d suggest, click the relevant link below:-

Specification for Insulation between and over rafters

Specification for Insulation between and under rafters

If these specifications don’t quite fit with your scenario, please feel free to use our Specification Generator to create a specification that fits your situation better.

These specifications will help you build spaces that are both warm in winter, cool in summer and quiet, even in urban locations.

Topic starter Posted : 09/03/2021 5:35 pm

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