Building structures out of sun dried earth is one of the oldest construction methods there are, and with this fun project kids can try their hand at early architectural techniques and build a miniature playhouse in the garden while they're at it!
Adobe, mudbrick and cob structures all use similar ingredients (sand, clay, water and some sort of binder like straw or sticks), and can be easily made in miniature version in the garden. After mixing up our batch of mud (we didn't have straw so we substituted some grass clippings and the fibrous parts of maple seeds) we pressed it into an ice tray with removable dividers. If you don't have one of these, the flexible versions would work well too, but a traditional version wouldn't be the best choice because the bricks would be hard to remove without falling apart.
Making strong bricks requires a fair amount of clay in the mixture. One way you can tell if your dirt will be good for bricks is to mix it with water in a clear jar until it is almost completely saturated and then shake it up... kids love this part. After the mixture is shaken for a while (about a minute or so), and then placed on a table to allow it to settle you will be able to tell how much clay there is because it will fall to the bottom of the jar.
Once you have removed your bricks from the mold they might need a little more squeezing to make them as compact as possible. Then either leave to dry for a few days in the hot sun, or you can bake them in the oven (if your climate is too humid) at a low temperature (about 150 degrees or so) until they are dry and hard, usually a few hours.
When the bricks are ready you can start building your structure using a soupier mixture of mud as the mortar. If you have any openings you would like to include (we made a window and a door for ours) you can bridge the top with a couple of sticks and then continue building with the bricks on top of that.
We made our roof out of some ferns we had growing and a few sticks, but you could also make the entire structure out of bricks (with sticks used to frame the roof). And that's it, you're done! You could leave it as is or....
... you could add a few embellishments to invite the elves or fairies to find their way in.
Happy Building!