It is more economical to maximize panel size and minimize the number of precast units on a project. This results in fewer erected pieces, fewer connections and fewer crane picks. However, the maximum size of a precast panel depends on a variety of factors. For example, the size may be limited by site conditions or the reach of the crane that will be used to set the pieces. A site with limited access, or one where the maximum panel weights are set by the crane capacity could be the overriding factor in determining panel dimensions. Similarly, the size or weight of precast panels may be limited by shipping or fabrication considerations specific to a region or individual precast supplier. Usually panels should not exceed a width of approximately 12'-0", without consideration for a special permit or escort. Also, panels that exceed 40' in length may require the use of prestressing to reduce handling stresses and minimize cracking. The maximum size of panels is also a function of the design loads and locations of building supports. In general, it is best to work with a MAPA precast supplier to determine the most economical sizes and dimensions for your project.