Architectural scale models are made of buildings, like houses, to check the shape or to show the shape to clients who have difficulty visualizing a three-dimensional structure. According to the experts at Architectural Models, "Models tell a story that everyone can understand and the story starts the second your eyes see the model." Architectural models range from simplistic, where details are suggested, to detailed, where the structure looks like the finished building. Most of the time the models are less detailed since sometimes details are still being decided and frequently a client will not want to invest in a highly detailed model, a project which can add thousands to the cost of design.
Design your building using the graph paper underneath of tracing paper to maintain the correct scale. In my example I used 1/8th scale and I used a simple house form.
Cut a foam core base large enough to represent your lot size or at least the area immediately adjacent to your building or home. Measure your floor plan at its corners and mark those points on your foam core.
Transfer your plan measurement of one wall from your plan to your foam core. Generally, you will have elevations. These are drawings of each of the sides of your home or building. Elevations will note windows, doors and other features. You can opt to make a copy of your plan elevations and glue the flat sides to your foam core. In my example I loosely translated the windows and doors in ink, directly on the foam core.
Proceed around the scale plan making a foam "wall" of each line drawn wall. This may become complicated if your building has lots of corners and recesses. In my example I am showing a wall projection and a recessed front door area.
Create all of your walls. I elected to create my gable as a second piece but you can make it one piece for a cleaner look.
Assemble the body of your building. This takes glue and patience. Position your largest single wall in the spot marked earlier on the foam core. Make sure it is straight by using a straight edge. Glue your largest wall to the foam core board. You might use straight pins to temporarily add additional rigidity while the glue dries.
Work your way around the floor plan carefully, building your walls as you go. You may need to trim away excess board at corners by mitering the corners or slot fitting them. A miter is to cut the foam at an angle such that the two angles match at the corner. A slot fit is where the foam core is partially cut ¼" back from the corner on ONE wall. By not cutting all the way through the foam the thin outer paper can be glued to the adjoining wall section. Basically, you are dealing with the thickness of the foam core and must adjust for it during model assembly.
Fit your roof or roofs by selecting the biggest roof mass first. This should cross from one side of your model to the other (particularly with gables), with hip style roofs you will span at the outer corners. (You may need to build inner props for large homes and building --to support the foam core.)
Glue your roof sections to the walls in order (from largest to smallest). Again, allow for the thickness of the foam core where necessary.