My goals are to make it wide enough and cushy enough that it'll be a nice place to sit.
We started by making a basic box that, along with the ply wood sides, would fit very snugly in the gap between bookcases.
I didn't think those 6 ft+ 2x4s should support such weight, without supports in the middle. Nick humored me, though he disagreed.
Then we covered the box with paneling on the sides that would show. It is plenty stable enough that we don't need to waste lumber on the sides that are hidden. I mostly plan on storing board games and maybe the odd blanket in the window seat.
Can we say holy sawdust!?! You should have seen my pants after kneeling it it.
Anyways, after having cut the lid to fit, we cut two side edge strips so it can open without hitting the decorative moulding on the bookcases and a long, skinny one that we will attach the hinges to.
Nick insists that the lid needs more support. Now i'm the one humoring him. He is currently gluing furring strips to it. Honestly, I'm not even convinced they will stick, but gluing wood to wood is much different than, say, when I hot glued glazed plates to the fireplace. Hot glue typically works on an advanced suction method. That's why when you hot glue two smooth surfaces to each other, they are easily separated. Wood glue, on the other hand, is actually absorbed into the grain of both surfaces and dries that way. Maybe they will stay, maybe they won't.
Tomorrow the glue will be dry and we can attach the hinges and the only thing the window seat will need is some decorative molding (That's gonna be a whole 'nother project) and a cushion.
One more phase of this project complete!