This paper considers input –output techniques and their application to the construction sector. Starting with the origins of the concept, Leontief model is addressed with use, supply and square matrices that provide the analytical framework to quantify the importance of construction in the economy. Several indices are used to show its role even if technological structural relationships should ideally be measured in physical units, whilst most tables report flows in volume terms. Construction seems to follow the economic destiny of manufacturing whose bell shaped pattern of industrialization and de-industrialization is acknowledged. There has been a shift of importance of some intermediate inputs away from manufacturing towards service inputs and, in more advanced countries, a change in the composition of primary inputs with relative decreasing importance of manpower
