The key factors influencing the cost of building an outdoor billboard are the material for the structure, the size of the billboard, the height of the structure and the configuration of the supports. A second cost factor is whether the billboard will be single- or double-faced. Costs as of July 2011 can range from $10,000 for a small, single-faced wooden billboard to $150,000 for a large, steel, double-sided one.

Single-Faced, Wood

It is difficult to build large or high billboards out of wood because the material does not have the structural strength. Typical sizes are 12 feet high, with the top about 25 feet above the ground. Widths can range from 25 to 48 feet. Costs range from $10,000 for the smallest billboards to $20,000 for the largest.

Double Faced, Wood

The cost for double-faced wooden billboards is about twice the price of single-faced ones because the wooden structure becomes more complicated. Single-faced boards can have angled supports at the rear while the structure for double-faced boards must be smooth on both sides. Costs for double-faced boards with the same dimensions as those in Section 1 range from $20,000 to $40,000.

Single-Faced, Steel, Monopole

Steel billboards supported by one steel post, either in the middle or at one end, are considerably more expensive than wooden boards but can be bigger and higher. Typical face dimensions range from 12-by-25 feet to 20-by-50 feet. The 40-foot-high billboards range from $40,000 for the smaller boards to $90,000 for the largest. Adding 10 feet of height adds about $10,000. Placing the pole at one end instead of the middle requires a stronger structure and adds another $10,000.

Double-Faced, Steel, Monopole

Adding a second face to a steel billboard requires a slightly stronger structure but does not greatly increase the cost. For the smaller boards, the increase is about $10,000, while for the larger boards, which already have a stronger structure, the increase is less than $5,000.

Single-Faced, Steel, Multipost

Supporting the billboard with several steel posts increases the cost for supports but decreases the cost of the board structure since it is supported at several places. Overall, multipost boards are slightly less expensive than monopole billboards for smaller boards that stand 40 feet high or less. Boards with heights ranging from 10 to 14 feet and lengths from 25 to 48 feet range in cost from $30,00 to $70,000, slightly less than the corresponding monopole boards.

Double-Faced Steel, Multipost

Double-faced multipost steel boards are also slightly less expensive than their monopole versions for lower, smaller boards. These boards have the advantage that they can easily be arranged in a V-shaped format that allows for better visibility from both directions and for more stability, with smaller supports and frames. Such boards typically stand 40 feet high and have dimensions ranging from 12-by-25 feet to 14-by-48 feet for each face. Costs range from $60,000 to $90,000.