Witnesses in many countries use a number of standard designs for construction that can be built in just a few days. The act of constructing a Kingdom Hall in this manner is called a "quick-build", although typically the preparation work involving the structural foundation and surrounding surface may take several weeks prior to the scheduled build. For various reasons, not all Kingdom Halls are constructed as "quick-builds" or using the standard designs. However, a noticeably dominant architectural style of Kingdom Halls is often used based on standardized design concepts and models, depending on needs.