Cardboard box house. Step 0: Buy something that comes in a giant box. Proceed to Step 1.
inspiration: cardboard favela (Brazilian slum dwellings) now this is pretty cool and I may use this idea as inspiration for a canal I want to build later on :)
This would be cool to build with Aiden and Kaylee this weekend!
How to make a cardboard gingerbread house
How fun is this!? DIY Cardboard Playhouses - @Elyse Exposito Exposito Woodbury Pehrson Larson of A Beautiful Mess
26 Coolest Cardboard Houses Ever
Divertidas casitas de cartón / Inspiration: build a big doll house; paper dolls and furniture to put inside.
Cardboard Brownstone Dollhouses from PLAYFUL | mer mag
Divertidas casitas de cartón. Fascinating. Think I would use chip boards rather than cardboard if I was going to this much effort ..... Extra strength.
Geodesic Dome cardboard house - Fun things to do with your kids on cold days! Lots of ideas in this post from Little Girl's Pearls!