Construction And The Built Environment

Construction and the Environment

Assignment One

The year 1992 and the Ð''Earth Summit' in Rio de Janeiro marked a paradigm shift in the attitude of the governments of the world, as over 150 delegates attended and recognised the importance of ecological issues to the future of humanity. This was of great significance to the construction industry, as one of the greatest consumers, and producers, of our economic system.

Ð''Construction accounts for 40% of the total flow of raw materials into the global economy every year Ð'- some 3 billion cubic tons. The industry accounts for approximately 9% of Global Gross Domestic Product and in England alone provides employment for around 1.5 million people' (http://www.businessandbiodiversity.org/construction.html).

The new attitude explains the role of conservation legislation in the U.K. which, amongst other things, sets out the issues that must be considered at the planning stage of a new development.

Biodiversity Ð'- The preservation of biodiversity is one of the most important features of the new approach to construction. Put simply, it is the range of different species that might inhabit a particular environment and the interconnections between them.

Ð''the variability among living organisms from all sources, including, 'inter alia', terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems'

- definition adopted by the United Nations Convention on Biological Diversity

Aside from the aesthetic appeals of biodiversity, there are a number of practical benefits. Historically, our food comes from a very limited selection of plants and animals but there is a great potential for increasing this range. Medical advances are often gained from drugs obtained from diverse plant species; similarly industry often harnesses new materials found in nature. Answers to the problems of sustainability, another ecological question, may be found by utilising new sources. Crops which have been narrowly bred for thousands of years may benefit from being crossed with wild varieties. The natural world plays an important part in maintaining our world, from soil enrichment and fertilisation of plants to regulating the temperature of the planet.

The loss of one species may drastically alter the situation of an ecosystem, as species are linked in complex chains and webs of dependence. Much extinction is caused by destruction of habitat, such as may occur when the land is used by construction projects. As well as the actual use of land itself, other less obvious factors arise, such as air and water pollution, noise and disturbance and dumping of rubbish. Even small developments may break up areas that previously were connected, leading to isolated animal populations.

The U.K, amongst 153 others, signed the Convention on Biological Diversity which led to the 1994 U.K. Biodiversity Action Plan and local Biodiversity Action Plans, setting out plans and targets for those habitats and species most at risk.

As well as aiming to minimise adverse effects of development, it is possible for construction projects aid to biodiversity Ð'- for example by soft landscaping (planting of trees and other flora) which can improve air quality and provide corridors for wildlife to traverse between natural areas.

Land Use Ð'- The way in which land is used is a key issue facing the U.K. in the near future, and no-one more than the construction industry. The recent flooding of the Thames and other areas shows this in a dramatic fashion. There are other considerations when the location of a development is planned.

Surveys indicating the various uses of land in the U.K. are regularly carried out through the use of satellite imaging. In 2000 in England and Wales, proportional use of land was as follows (in percentages):

The amount of land in agricultural use is decreasing, and a greater amount of development is occurring on what was previously farmland. It is predicted that by 2016 nearly 12% of England will have become urbanised, the main culprit being new housing. According to the Environment Agency, 31% of land used for residential uses originated from farmland.

Two widely-used terms in this arena are brownfield and greenfield. Brownfield refers to sites that have previously been occupied by a permanent structure, greenfield to virgin land. A governmental target has been set for 60% of new housing to be sited on brownfield areas.

As the risk of flooding is expected to increase due to climate change, there can be a conflict between the desire to build on flood-safe areas and to utilise brownfield sites, as many of the latter are situated in areas known to be at risk from flooding. Another problem is that the greatest need for new housing is in the South-East, whereas more available brownfield land is located in the North due to the decline of heavy industry. Building on previous industrial sites has its own problems as there may be contamination in the soil itself, something that has to be assessed at the planning stage as part of the general site evaluation.

Different land uses in Britain in 2000

http://www.environment-agency.gov.uk/commondata/figureimages/f1_land_use_fs_937072.gif

Green Belts Ð'- Another feature, linked to the above, that must be contemplated, is the Green Belt. They are a man-made feature of the natural environment in the sense that they are areas, typically encircling large urban centres, set aside to be maintained as a rural barricade against cities. They were first officially introduced in the U.K. by Minister of Housing Duncan Sandys in 1955. The most well-known Green Belt is probably the one that surrounds London, but there were by 2003 14 in total, making up 13% of English land (16,766 square kilometres).

Area(in Km2) Region

5,133 London (Metropolitan Green Belt)

2,578 North West (Merseyside and Greater Manchester)

2,556 South Yorkshire and West Yorkshire

2,315 West Midlands

825 South west Hampshire and South east Dorset

688 Avon (Bristol and Bath)