Prefab includes any component of the home that is fabricated off-site. Prefab can range from a pre-constructed wall arriving on site, to an nearly-completed housing unit that only needs to be bolted to the foundation. Modular housing, which are homes largely prefabricated off-site, is a type of prefab construction.

Some fun facts about the history of pre-fab construction:

• Circa AD 43, the Romans used prefabricated building elements to build their forts quickly in newly conquered Britain.
• The first mention of a prefabricated building was in 1160 to 1170 by Wace as confirmed by Pierre Bouet. In the special May/June 2015 edition of the French magazine Historia, he spoke of a castle transported by Normans in ‘kit’ form.
• In the 1500s, the timber components of Nonsuch House (no longer standing) were crafted and painted in Holland and then later assembled in London.
• The Crystal Palace was assembled in Hyde Park, London from prefabricated cast iron components for the Great Exhibition of 1851. It was then dismantled and assembled elsewhere.
• For the 1889 World Fair in Paris, Gustav Eiffel designed a ‘temporary’ tower to act as the gateway to the exhibition – all assembled out of prefabricated iron elements.
•  In the United States, several companies including Sears Catalog Homes began offering mail-order kit homes between 1902 and 1910.
• In the United Kingdom, more than 156,000 prefabricated homes were built between 1945 and 1948