To make a house in Little Alchemy 2, you will need to combine the elements of Building, Wall, and Roof.
First, combine the elements of Mud and Pressure to create Building. Next, combine the elements of Building and Fire to create Wall. Finally, combine the elements of Wall and Water to create Roof. Once you have all three elements, you can put them together to create a House.
Creating a House takes a little bit of trial and error to find the right combinations of each element, so don't be discouraged if it takes you a few tries to get it right. With a bit of patience and a little creativity, you'll eventually be able to make a House in Little Alchemy 2.