Attic furnishing

[österfeldt]

I'm at the starting point of furnishing our attic and have a few considerations.

The roof trusses are only 145*45 and therefore need to be reinforced significantly (195mm) as I'm planning to insulate about 300mm.
Has anyone had the same conditions?
I'm considering a solution with light wood beams (H-beam) but doesn't that mean there will be a difference in the insulation board's dimensions???
Is there any enlightened person out there

 

[Faidros]

Considering a solution with a wooden light beam (H-beam) but then it differs with the measurement of the insulation board???

You can insulate the beam like this before you press the boards in place: