Things You'll Need
Furnishing and building dollhouses can get expensive if you have each fixture custom-made or even buy them in standard sizes from the store. Luckily, Styrofoam is a versatile material that you can cut into architectural features such as stairs. Use a simple process to turn a block of Styrofoam into a miniature staircase.
Cut a block of Styrofoam with a serrated knife into a piece that is as tall and as wide as you want the staircase to be. Determine the height by how high you want the top step to be. Cut the block so the depth -- the distance between its front and back -- fits where you want to place the staircase in your dollhouse or diorama.
Lay the block on its side.
Draw the stairs you want to cut out onto the side of the Styrofoam block. Draw them as you would see a set of stairs from the side, with short alternating horizontal and vertical lines, until you reach the end of the block.
Cut along your marker lines, cutting straight through to the opposite side of the block, using a serrated knife.
File the cut edges of the Styrofoam with a metal file to smooth them a bit. The stairs will likely have a bumpy texture because of the makeup of the Styrofoam.
Cover your stairs with paper or card stock to create a smooth texture, or leave them bumpy and paint them gray for a stone castle look.