Sturdy, well constructed, but light enough that I could carry it upstairs.  Easy to assemble with a power drill.  Be sure to check the alignment of the top nest cut out before you screw it down.  Note:  the post you screw into is real wood.  The underside of the top nest is chip board and uncarpeted.  The top edges of all the nests were carpeted.  My two large (15-16 lb.) cats were playing in it before I could assemble it.  Nests were very roomy - they had plenty of space, especially when hanging their heads over the cutouts.