The construction industry of Japan is a large component of the Japanese economy in terms of economic output and employment. Its history is one that mirrors closely the overall economic path of the country, from establishment of the capital during the feudal era, through economic modernization and imperial rule, and until today with the recovery and great economic expansion of Japan's post-war years. More recently, the industry has been influenced by preparations for major events, most notably the 2020 Summer Olympics, and a push towards sustainability. Contemporary challenges include maintaining access to labor and combating political corruption. History Classical and feudal era The first physical record of a construction industry in Japan is Horyuji, a Buddhist temple that was completed in 607 and is now the world's oldest wooden building. More comparable to a modern industry can be seen starting in Edo, now Tokyo, during the Edo Period. By the 17th century, Edo was the world's largest city, with a population of over one million. Edo carpenters benefited in particular from the Sankin-kōtai system, which required daimyo, feudal lords, to spend alternating years in Edo. The extent of the development this spurred in Osaka, Edo and traveling stations was such that regulations on logging had to be established to ensure a sustainable supply of construction materials. The typical housing for lower classes was all-wood buildings with the expectation of frequent reconstruction. Due to the frequency of large fires, rebuilding was an expected, and even celebrated as part of life in Edo. Early modern and imperial era In the Meiji Period, from 1867 to 1912, seeking to promote industrialization and adoption of Western practices, the government launched infrastructure programs that produced the first construction contractors in Japan, some of which still exist today as major construction firms. Engineers from Europe and the United States introduced Western building techniques, and buildings were constructed in Western architectural styles. During this period, public works projects were contracted to companies based on competitive bidding systems. This period also saw the first formal studies in Japan of the architectural implications of its many earthquakes. Early efforts in the late 19th century were conducted by the country's pioneering seismological societies and architectural engineering students investigating the aftermath of earthquakes and their effects on buildings. Japan's first building code was enacted in 1919 and additions in later years would include provisions to help prevent earthquake and wind damage.