How to Build a Massing Model

Determine your building's form. Draw the profiles of the design to scale on the foam using a pen. The massing model will be built to a scale smaller than the actual building, but use measurements that can be translated to a larger form and still maintain the proper proportions. For example, 1/16 inch equals 1 foot, which is 1/192 of actual scale, is a common choice for massing models. Measure using a ruler or architectural scale, where each 1/16 inch on the ruler equals 1 scaled foot. Other scales you may choose include 1/32 inch, 1/20 inch, 1/10 inch, 1/8 inch or 1/4 inch equals 1 foot.

Turn on the hand-held electric foam cutter and allow the blade to heat up. Hand-held electric foam cutters are available at most craft and hobby stores and, at the time of publication, cost approximately $10. Electric foam cutters are better to cut foam than craft knives and other blades because the foam dulls the blades, causing rough cuts; this results in poor craftsmanship.

Avoid touching the hot electric foam cutter blade and work over nonflammable surfaces, such as concrete. Wear gloves to avoid burns from the handheld electric foam cutter.

Cut the form of your structure following the profiles drawn on the faces of the foam block. Move the hand-held electric foam cutter slowly and smoothly through the foam. Do not discard the cut pieces; instead replace the pieces on the model in the spaces where they were originally located to reference the profiles drawn on the foam faces. Use tape to hold the cut pieces in place or carefully hold the pieces against the massing model with your gloved hand.

Remove the cut foam pieces from the rough massing model. View the model from all sides and measure the dimensions with a ruler or scale to ensure it is cut to the dimensions originally drawn on the foam block.

Cut any necessary details of the design, such as niches, reveals, inset windows or ornamentation, into the model using the foam knife.

Gently sand the finished form with fine sandpaper to create an even texture over the model and coat it with gesso to protect it.