Any "prominent" city and particularly London are not good examples. In a non-main city the cost of a newly built house is basically the cost of the land + the

Any "prominent" city and particularly London are not good examples. In a non-main city the cost of a newly built house is basically the cost of the land + the cost of construction (done at a more industrial level, i.e. let's say a lot of 16 houses or a building with 30-40 flats is built with costs that are some 20-30% lower than those to re-build a single house/flat) + the margin of the builder/developer (which often is not exceeding 15 or 20%). I will give you some real world costs for my area (Italy, Tuscany, non-main-city): Plot/land (incidence on built surface) 500 Euro/m2 Building costs 1200-1400 Euro/m2 Projects/Taxes/permits/financial costs 500 Euro/m2 Final sale price 2800-3000 Euro/m2 Same in the nearest "main" city , Florence: Plot/land (incidence on built surface[1][2]) 1500-2000 Euro/m2 Building (re-building) costs 1300-1500 Euro/m2 Projects/Taxes/permits/financial costs 800 Euro/m2 Final sale price 4000-6000 Euro/m2[2] [1] largely this is about buying, (partially) demolishing and rebuilding an existing building as there are very few possibilites of a completely new building on a "virgin" land plot [2] of course this depends a lot on the exact location