Construction can be seen as an industry concerned with the production of the built environment. As an industry, its inputs cover a large variety of skills and materials. Its output covers many different types of products and services. As a sector of the economy, it includes the assembly of buildings and structures on site, the production of materials and building components and, indeed, the whole supply chain. This includes architects, surveyors, civil and structural engineers, plant and tool hire, construction product manufacturers and distribution. The construction sector is treated as one sector but, in fact, it covers a wide variety of work across many different areas. Construction output covers everything from the building of housing, commercial and industrial properties, education and health facilities to the building of vital infrastructure for water, energy, roads, rail, telecommunications and ports.

Whatever an individual or collection of individuals may wish or need to do in the economy or society, they will require construction to have taken place first to be able to do it. People need houses to live in, schools and universities to undertake learning, clinics and hospitals to make or keep us physically fit and comfortable, and offices to work in and shops to buy goods in. Even if we work from home and shop online then we still need the internet infrastructure to have been built. In addition, we need roads to drive on, rail infrastructure for trains to travel on, clean water for drinking and bathing, electricity and gas to power heating and lighting. As the built environment has grown over many years, the current buildings and infrastructure have developed over time, and, as a consequence, the repair, maintenance and improvement of existing buildings and infrastructure is also vital.

To measure the scale of investment in construction as part of the whole economy, the United Kingdom National Accounts, also known as The Blue Book (see Office for National Statistics 2017), contains a chapter entitled “Gross Fixed Capital Formation” (GFCF), which presents the total invested by the economy in plant and equipment and buildings and structures.