My mind was blown the other day when a teacher colleague shared this great project that integrates design and science in a super affordable way! She calls it the Penguin Project. The skinny is: you design a zoo habitat structure for a penguin by focusing on building materials and the science of heat. The amazing part of this project is the "penguin" is represented as an ice cube. The goal is to keep the ice solid as long as possible. The longer the ice cube lasts, the better the habitat.
There is a design project very similar to the zoo project authored by educators at Auburn University. Its a PDF document that has background information, materials lists, and lesson plan activities.