Custom-manufacturing in the window and door industry is quite a different animal from other industries. First, most window and door products are manufactured in large, automated, industrial facilities. Custom work has to be designed into the automation and flexibility of the factory. Then comes the distribution. Custom manufacturing by definition means longer lead times. Standard sizes allow manufacturers to produce for inventory, distribute the product into regional warehouses, and, when an order comes, be able to bring the product quickly to the customer. The distribution costs are lower, at least if the inventory resembles somewhat the market needs in the future. Forecasting that is more an art than a science. If forecasting is inaccurate, shifting inventories between distribution points and pushing overstocked items on the customer increase costs and lower customer satisfaction.

In Germany, custom manufacturing of windows and doors has been a necessity, not a choice for several reasons. Unlike the United States, where standardization of features and sizes has provided opportunities for making the same product over and over, in Germany, standardization has been difficult. Most construction revolves around renovation not new construction. Because of the age of buildings and the historical nature of many of them, openings and requirements are different for almost every project. Recognizing this, German manufacturers designed factories around the requirement of customization. Fully automated, walking through one of these window companies in Germany feels like an automotive factory: cars of the same platform move along assembly lines, some convertible, everyone in a different color, different engine sizes, and features specified by individual customers. Only that the variation possibilities of windows are even higher than those of cars. Thousands of hardware options, indefinite sizing, hundreds of glass options, thousands of color options, and other features the customer could specify. All that German manufacturers have managed to integrate into industrial production, while costs and delivery times resemble those of manufacturers producing standard products.

The trend in the window and door industry in the United States is moving towards the European system: Designers require custom products to expand their possibilities and competitiveness. The legal environment adds to the variability of products based on requirements for energy efficiency, wind resistance, and security. Standard product manufacturers see their offering expand continuously, undoing the cost advantage of manufacturing standard units. It will not be long until a manufacturer here in the United States will take the European manufacturing example and open a factory that will change the U.S. window and door industry profoundly. While maintaining competitive pricing, customers will be able to procure custom-made products without extended delivery times. Until then, the most experienced importers of European products will lead the market, at least the portion that likes custom products.