Economic credentials

Concrete is the 'backbone' of the UK construction industry. Whether a building's structure is made of concrete, steel or timber, it will undoubtedly be built on concrete foundations. The floors of commercial or industrial premises are also typically concrete.
 
As the UK economy grows, so does the construction sector, and within that, the demand for concrete. Since 1999, the country's GDP has grown by an average annual percentage of just over 5%, translating into a growth for the construction and building materials industries. In 2004, the construction industry employed 6.6% of Britain's total workforce and generated around 10% of its GDP.
 
Concrete's economic significance as an essential supplier to the UK's construction industry is considerable. But the UK's almost complete self-sufficiency in concrete and the materials needed for its manufacture make it even more attractive both economically and environmentally. A key principle of sustainability is that a product should be consumed as near to the place of its production as possible to:
 
  • Minimise the need for transport and the associated environmental, economic and social impacts of transportation.
  • Support the local economy and hence local society.
  • Prevent the export of the associated environmental impacts of production to another location with less stringent environmental and social protection legislation.
 
Due to our dependence on fossil fuels and the dwindling UK reserves we must face-up to increasing energy costs and the real risk of fuel poverty which will potentially impact the most vulnerable groups of our society. The UK climate is changing. Current predictions from the UK Climate Impacts Programme (UKCIP) show that by the 2080s, annual temperatures for the UK may increase between 2-3.5oC. In London this could be as high as 8oC, taking the peak summertime temperature to over 40oC, due to the Urban Heat Island effect (UHI). This will have a considerable impact on the temperature of the internal environment of the buildings that we are designing and building today, especially those of a lightweight construction, which are likely to overheat by 2020 and need energy intensive air conditioning to make them comfortable.
 
In all buildings, heat is generated by people, cooking, electrical equipment, computers, lighting and passive solar gain which means that buildings can overheat during the summer. A particular benefit of concrete is its high thermal mass. In the summer, exposed concrete absorbs this heat gain and keeps the internal temperature 6-8oC below the peak external temperature, providing internal heat gains are kept reasonably low and good solar shading is provided. Night-time ventilation is then used to cool the building, priming it for the next day. In winter, thermal mass in concrete walls and floors stores energy from the heating system, passive solar energy and the incidental heat from cooking, lighting, people or other internal sources. This stored energy is then released at night, thus sustaining warmer overnight temperatures and reducing the use of heating energy.
 
Excellent airtightness is also easily achieved with concrete construction; this results in better managed air change rates, reduced energy consumption for space heating and financial savings for the occupant. Concrete homes have achieved airtightness rates even better than the demanding Swedish design benchmark of 2.88 m3/h/m2 @ 50 Pa, which is of growing relevance as airtightness requirements are set to become more stringent in each successive revision to the UK Building Regulations. Another benefit of utilising concrete's thermal capacity and introducing natural ventilation is the improvement in natural light. Exposed concrete can reflect light far into a building's interior and this can reduce the need for artificial lighting, saving energy and therefore money.
 
It is possible for the UK to be 100% self-sufficient in concrete production, insulating the country from the international volatility often seen in the oil and iron ore markets. The economic good news extends further, in that concrete and many of its component materials are net exporters, helping the balance of payments and contributing to national wealth.
 
In 2005, the UK exported 535,000 tonnes of ready-mixed concrete, worth nearly £9 million to the UK economy. For precast concrete in 2005, £130.5 million worth was exported. The UK's self-sufficiency in concrete compares favourably to the situation for construction's other main building materials, steel and timber. UK steel production was 11.7 million tonnes in 2002, although approximately 50% of this was exported. A further 8.72 million tonnes of steel were imported into the UK in that year (ISSB). A simple calculation based on these figures shows that the UK needed to import almost 60% of its total requirement for steel, including structural steel, in 2002.
 
Similarly for timber, more than 98% of the timber used in Britain for construction is imported. A recent BRE report shows that timber's predominant impact on the environment comes from the transportation of the raw materials. These constituted 99.5% of all impacts with the largest contributions due to the long distances travelled to bring in sawn timber from Canada, Finland and Sweden. One of the problems with importing timber is that as much as 60% of the tropical timber used in the UK comes from illegal logging.