ᐅ Which type of masonry combined with insulation is best for an extension?

Hello,
We are planning an extension.
Unfortunately, the plot is relatively narrow.
We have three types of masonry to choose from:
Facing brick plus Poroton
Facing brick plus aerated concrete block

We want a U-value below 0.18.
How should we insulate to achieve this value?
The exterior wall should be less than 350mm (14 inches) thick.

Thank you for your help!

Hello,

ricci1212 schrieb:

The exterior wall should be under 350mm (14 inches).

That’s not possible; not even with an extension built according to the specifications of a prefabricated wall.

Kind regards

Hello building expert,
Here is the wall structure:
17.5cm (7 inches) aerated concrete, 8cm (3 inches) insulation?, 11.5cm (4.5 inches) facing brick
Looking for good insulation with a small thickness?
Best regards

Hello,

ricci1212 schrieb:

We want a U-value below 0.18.
How should we insulate to achieve this value?
The exterior wall should be less than 350mm (14 inches) thick.

Just calculate it yourself. Or have it calculated 🙂