Enlarge the topographical site plan by increasing the scale of the drawing on a large format copier. Determine the scale of the model and increase the scale by dividing the final scale by the initial site plan scale. For example, if you would like to construct a site model at 1/16 inch equals 1 foot and the site plan is 1/30 inch equals 1 foot, then you would enlarge the site plan 30/16 times, or 187.5 percent. Enlarge the site plan by the calculated percentage.
Place the enlarged site plan photocopy over the chipboard and run the pounce wheel over each successive contour on separate sheets of chipboard. The pounce wheel pokes a series of holes through the photocopy into the chipboard to trace the curvilinear contours, without destroying the photocopy. Most site plans have many contours, so you need to have enough chipboard sheets to cut each contour and build the surrounding buildings.
Cut the traced contours from the chipboard sheets using a craft knife. Replace the craft knife blades frequently to provide cleaner, easier cuts through the chipboard. Cut the larger, bottom layers first and stack the successive layers as delineated in the site plan; the multiple, stacked layers create the three-dimensional landscape and topography.
Glue together each layer of the stacked chipboard. Cut out the footprints of the surrounding structures and the proposed building with multiple passes of the craft knife and T-square. Cutting out the footprints after the chipboard layers are glued provides cleaner vertical cuts in the model. Cut carefully to avoid stray incisions.
Build the simplified form of the surrounding structures out of chipboard and glue, using your scale, pencil and T-square. The surrounding structures are usually simple chipboard boxes joined at their edges with glue, although you can add building details, such as windows, doors, cornices and cladding. Place the structures in the cut footprints.
Use dowels to represent trees. Drill holes, the same diameter as the dowels, into the site model and place the dowels into the holes.