Subterranean construction has been around for a long time , as far back as during the industrial revolution. During mass urban migrations, factory workers were housed in cellars and basements, in cold, damp, badly ventilated rooms.. At the end of the 19th century, some 20,000 people lived in basements in Amsterdam alone. Aboveground city expansion primarily accommodated the rapidly growing middle class. More recently the concept of EARTH SCRAPPERS has muted, this will potentially revolutionise the use of the underground space.