Tilia/Basswood is used for the interior sides of drawers in cabinets because it doesn't warp. Anyone struggling with a pine box that wants to cup and spread would appreciate Basswood.
I build nucs with solid-wood front and back, and ply sides. I cut a rabbet for a frame rest, exactly the same as a full-size box. Top and Bottom are "migratory" cover design out of ply with 2x2 lip on the front and back.
I screw or rope the top and bottom on (depending if it travels or not).
The advantage of this system is 1) the ply side to solid front can be screwed into solid wood, and is a solid connection, making a long lasting box. 2) The dimensions are exactly the same front to back - 19 7/8 - as full-sized hives. 3) all pieces are interchangeable and compatible with full-size bottoms and tops. Making a double hive simply consists of sistering up 2 nucs on a full size bottom with a little divider strip tacked down the center of the bottom.
I have a variety of heights -- regular deeps and mediums for nucs, and trap boxes that are up to 24" high. The taller boxes are a response to the Seeley research on swarm selection of 40 liter volume. I add medium frames, so there is a lot of free space in the box. The bees start building comb on the frame, and I recover them before they build (very far) into the free space below. (well, most of the time).
The regular and medium depth utilize scraps from rabbeted front pieces of full size cut-offs. The extra-tall design uses a nominal 8 (7 1/2 net) fence board run vertically. The vertical boards are just the right width for a 5 nuc. They are slower to make (each rabbet must be cut individually) and have a risk of cupping on the long axis. The ply sides can be scrapped out of any thing. With a butt connection to the rabbeted front, their width (1/4 to 3/4 scrap) is totally inmaterial. Tops are cut to 9" to accomodate any size side.