The antonyms for the word "more well-constructed" would include poorly constructed, badly constructed, shoddy, and inferior. These words indicate that the object in question lacks quality, durability, and overall structure. A poorly constructed building, for example, might have uneven floors, cracks in the walls, or unstable foundation. A badly constructed garment might have inadequate seams, weak stitching, or low-quality materials. Shoddy and inferior are also used to describe products that are of low quality, often produced quickly and without proper attention to detail. Antonyms like these underscore the importance of quality and attention to detail when constructing and manufacturing goods.