Architectural Structural Models

There are two basic types of architectural models: structural models and presentation models. Structural models typically show how the framing of a building is put together. Presentation models typically show what the house would look like after it is built.

Structural models are often built out of balsa, and many balsa architectural model kits are held together with pins. A more inexpensive method is to make the model from construction grade lumber, which was initially suggested to me by a hobby shop clerk who used it to make accessories for model train layouts. The other suggestions that I have come from my personal experience, either building balsa-and-tissue models or from cutting and assembling architectural structural models.

Cutting the Stock to Size

The best tool to use to cut the construction lumber down to model size is a table saw. You will lose about half of your wood to sawdust, but a table saw will give a smoother and straighter cut than a bandsaw or a jigsaw. You could possibly rip the lumber down to size on a radial arm saw, but you would have to make more complicated jigs to keep from breaking the wood in the smaller sizes. I have gotten my best results on an old 9” Rockwell Delta table saw using a 9” Piranha carbide tooth saw blade. It seems that the sharper the teeth, and the closer together that they are, the smoother the cut surface you get.

The first operation I do is to cut off one of the edges in a ripping operation, to straighten up the edge and get rid of the rounded corners. The next operation is to rip strips off that are a scale 2” thick -- so I end up with strips that are about 1.50” wide and about .167” thick (for 1”=1’-0”). Get a healthy estimate of how many pieces of each size you need (2 X 12, 2 X 6, 2 X 4, etc.) before you start ripping them down to width. I usually make a simple jig to keep from breaking the wood as I rip it at this time by: (1) setting the rip fence to the desired width position, (2) lowering the blade below the table, (3) clamping a piece of relatively thin lumber over the saw table, (4) turning on the saw and raising the blade, which cuts an opening for itself as it comes through the board. This will eliminate openings in front and to the sides of the blade, which will keep the wood from being pulled down and broken.

Yellow pine has given me the smoothest cut surface parts, while the pine used for studs tends to be fuzzy. A length between 1’ and 3’ seems to be the optimum, because shorter pieces are difficult (and unsafe) to maneuver through the blade, and longer pieces are unwieldy, unless you have help.

I generally use a razor saw to cut the parts to length, using a small “miter box” made up for the project. Razor saws are relatively inexpensive, and can be purchased at a hobby shop. You can substitute a fine tooth miter saw or a hacksaw with a sharp blade to cut the ends also.

Assembling the Model

The first thing you need is a floor plan. Then make elevation drawings of each wall, showing all the framing for each wall -- remember to take into account that these walls will fit with other walls, just like in a real house.

The technique I use to build the wall sections is to put down a layer of corrugated cardboard or foam, then put my wall elevation drawing on top of that, then put a layer of wax paper on top of the wall elevation drawing. I then can assemble the wall section using white glue on top of the wax paper. The drawing helps me keep the wall straight and square as it is being assembled, the wax paper keeps the wall section from being glued to the drawing, and you can use pins pushed into the cardboard (or foam) to hold the pieces in place as the glue dries.

You can build the wall sections before, after, or while you are working on the foundation and floor joists. Structural models usually include foundation walls, but not the footers. I usually cut the wood for the foundation walls, glue it together, and paint it white or gray before I put the sills and joists on top of that. You can also paint or stain the sills green, since they are pressure treated lumber.

One of the handiest things to use for subfloors is sheet cardboard. You can draw lines on the cardboard to represent the 4’ X 8’ sheets that would make up the subfloor. You can also lightly draw the floorplan on the cardboard to aid in positioning the wall sections. Of course you can glue the cardboard to the joists and glue the wall sections to the cardboard.

I would advise that you make a small model first to work out your techniques before you try to make a large model. As an assignment I would suggest an 8’ X 8’ or an 8’ X 12’ floor plan, with an exterior door, a window, an interior partition with a door, and a roof with an overhang on all four sides. You should make this model at 1”=1’-0”.

(I developed this material for the drafting and design classes that I used to teach. The purpose was to get the students familiar with the commonly used western framing/platform framing building techniques. Using drafting equipment they could draw the walls to scale to have a pattern to assemble their model walls. This type of model construction was based on techniques I learned building balsa and tissue airplanes many years before. Assembling the models on top of the drawings covered with wax paper allowed the students to see the drawing they were using as a pattern, but not have the model being assembled stick to the drawing. This assignment became obsolete when 3D CAD systems became relatively inexpensive and models could be built in 3D – which also saved a lot of time, material, and mess.)