Thanks @loke and @callen!
Something like this?
Thick Skin of Ice lvl15
Cr(Re)Aq
R:T, D:D, T:I
The caster creates a thick layer of ice around himself. The ice is 6 inches thick, crystalclear and moves as the casters body (Re req.).
The armor is bulky, its Protection is 9 and its Load is 10 - it is more about the bulkiness, not about how heavy it is. You can move with it but only walking speed. Casting is possible but only with subtle motion. All the Perception based rolls are penalized by -6 because you cannot really hear or see properly in the armor.
An Int+Finesse roll vs EF 9+ can mitigate the casting penalty by creating more loose part around the arms.
EF 12+ made the Percetion penalty to -3 and an EF 15+ creates a masterpiece from ice: vision and hearing is almost unhindered, the Load of the armor is only 9.
(Base 4, +1 T, +1 D, +1 Re req.)