I remember a book from when I was a child (born in 1974) that was about this family that was made of blobs and they would use their bodies to make shapes (like houses or whatever was needed). Both my sister and I remember this book but have no idea who wrote it or the title. Does anyone know?

I've been looking for the same book. I have found the answer on the net. The Barbapapa is the family. The books where written by Annette Tison and Talus Taylor. Bad news is they are not cheap. I haven't shopped everywhere but they need to put these books back into production just to make them cheaper. There is a whole series of this family.