Permanent window treatment

[Soulshaker]

I'm looking for advice on the best way to permantly treat 3 windows on my outer shell. I kept them in the build for aesthetic reasons but want to enclose for studio. Basically they look normal on the outside but are on the outer shell of room within room so I won't ever see or access them once build is complete. Thanks to all for your time & expertise,

Jason

[Gregwor]

Put some dense fabric inside the window. It shouldn't touch the window. It should be a color that won't fade in sunlight (white might work great). Put some desiccant in the cavity. Board up the window using sheathing with the same surface density as the rest of your outer leaf. Done.

Greg

[Soulshaker]

Thank you Greg,
Can I also include white wood blinds to match the aesthetic of the rest of my house or even a decal from a print shop of blinds stuck to the glass like the pic I provided? Without the Zebra If so it would be the glass/blinds/desiccant/dense fabric/OSB correct? Here is a dense fabric I've used for rapping mineral wool Bass Traps. Do you think this would suffice?

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[Gregwor]

The fabric in the window would only be there to make it look "normal" from outside. So yes, use whatever you want. The desiccant is there to control moisture. After that, use whatever you want for sheathing to achieve the correct surface density. Note: the window frames are typically not sealed well. The voids between the window frame and the wall framing material are usually filled with very light spray foam type crap. You should dig out an inch deep if possible and fill it with 100% silicone caulking to achieve the mass you need while retaining a good seal.

Your order of materials is correct.

Greg

[DanDan]

I cut a slab of rock wool to squeeze neatly into the window. Wrap in a 'Blackout Blind' Sheet of MDF blocking on the inside.
Acoustically damped, never discolours and looks totally normal. Apologies for the sunshine, won't happen again....

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