In 2008, the installed costs of sprinkler systems ranged from US$0.31 – $3.66 per square foot, depending on type and location. Residential systems, installed at the time of initial home construction and utilizing municipal water supplies, average about US$0.35/square foot. Systems can be installed during construction or retrofitted. Some communities have laws requiring residential sprinkler systems, especially where large municipal hydrant water supplies ("fire flows") are not available. Nationwide in the United States, one and two-family homes generally do not require fire sprinkler systems, although the overwhelming loss of life due to fires occurs in these spaces. Residential sprinkler systems are inexpensive (about the same per square foot as carpeting or floor tiling), but require larger water supply piping than is normally installed in homes, so retrofitting is usually cost prohibitive.