1. THE ENVIRONMENTAL IMPACT OF CONSTRUCTION MATERIALS AND METHODS
DAVID HAINSWORTH

2. LESSON OBJECTIVES In today’s lecture you will be learning about :
The environmental impact of construction materials
The environmental impact of construction methods

3. The construction process not only consumes the most energy of all sectors in the UK and creates the most CO2 emissions, it also creates the most waste and is responsible for the most pollution.

4. POLLUTION FACTS
10% of the UK CO2 emissions arise from the production and use of building materials.
Each year the UK construction industry uses 6 tonnes of building materials per head of population.
Materials production and construction accounts for an estimated 122 million tonnes of waste, or 30% of the total arising in the UK.

5. OBTAINING AND PROCESSING MATERIALS
Obtaining and processing materials can affect the environment in three main ways : 1) EXTRACTION 2) PROCESSING 3) TRANSPORTATION

6. EXTRACTION
This requires heavy plant which consumes energy and produces noise, dust and exhaust fumes, which leads to climate change
This process also causes a permanent change to the landscape e.g. stone/aggregate quarrying

7. AGGREGATE QUARRYING

8. PROCESSING
Processing the material e.g. iron ore requires energy consuming plant, noise and dust, and the creation of waste products e.g. slag

9. BLAST FURNACE
AIR POLLUTION LEADS TO THE GREENHOUSE EFFECT AND CLIMATE CHANGE

10. TRANSPORTATION
Once processed, the materials will then need to be transported to the location which they are to be used, using petrol and creating exhaust fumes, which in turn causes climate change

11. TRANSPORT - FUEL EMISSIONS

12. MATERIALS USED IN CONSTRUCTION
There are 4 main materials used in construction and we will now look at their specific environmental problems.

13. TIMBER

14. DEFORESTATION
MORE THAN 25% OF THE WORLD’S TROPICAL FORESTS HAVE BEEN CLEARED SINCE WHAT IS HARDWOOD USED FOR IN CONSTRUCTION ?

15. LOSS OF ANIMAL AND PLANT SPECIES

16. TIMBER SUMMARY
Timber can be classed as a renewable material (especially softwood)
Relatively low energy used in the logging and sawing process
High transportation costs

17. METALS

18. METAL ORE QUARRYING
WHAT SORT OF METALS ARE USED IN CONSTRUCTION ?

19. METALS SUMMARY Metals are classed as non-renewable
Extraction and processing uses huge amounts of energy, causes air pollution and creates waste products, and changes the landscape
Decreasing ore quality makes it necessary to extract more ore from the earth

20. CONCRETE

21. CONCRETE
WHAT IS CONCRETE MADE FROM ?

22. CEMENT BASED PRODUCTS SUMMARY
Classed as non-renewable
Made from limestone, chalk, clay, aggregate and gypsum
These raw materials must be mined then processed, which requires a huge amount of energy
It is estimated that 8% of the total worldwide human generated CO2 originates from cement production

23. PLASTICS

24. PLASTICS
UPVC PRODUCTS INCLUDE WINDOWS, DOORS, SOFFIT, FACIA, RAINWATER GOODS, ELECTRICAL AND PLUMBING COMPONENTS

25. PLASTICS SUMMARY Classed as non-renewable
Plastics are petrol-chemical products (which use oil during production)
Alternative to timber
Needs large amounts of energy to produce and creates hazardous waste products e.g. dioxins

26. EMBODIED ENERGY
The energy required to produce and transport materials is known as the “embodied energy”
The following chart shows the embodied energy in several common building materials (excluding transportation energy)

27. MATERIAL ENERGY FOR PRODUCTION TIMBER 1 BRICK 4 CEMENT 5 PLASTIC 6 GLASS 14 STEEL 24 ALUMINIUM 126

28. ENVIRONMENTAL PROBLEMS ASSOCIATED WITH THE CONSTRUCTION PROCESS

29. Can you think of some environmental problems caused by the construction of new buildings and structures ?

30. PERMANENT CHANGE TO LANDSCAPE
IN BUILDING THE THREE GORGES DAM IN CHINA, LARGE AREAS WERE FLOODED, AFFECTING LOCAL VILLAGES AND WILDLIFE.
EVEN ON THE SMALLEST BUILDING SITES TREES, HEDGEROWS AND WATER COURSES CAN BE AFFECTED.

31. NOISE/DUST
NOISE AFFECTS LOCAL AREAS, DUST CAN SPREAD OVER A WIDER AREA AND CAN CONTAIN POLLUTANTS

32. RIVER POLLUTION
SILT RUN OFF FROM BUILDING SITES/QUARRIES

33. GROUND POLLUTION
RUBBISH/EXCESS MATERIALS CAN BE LEFT, SPILT, BURIED OR BURNT CAUSING GROUND POLLUTION

34. LANDFILL
WASTE PRODUCTS AND RUBBISH THAT CANNOT BE RECYCLED ARE REMOVED FROM SITE AND TAKEN TO NEARBY LANDFILL SITES, WHICH CAUSES GROUND POLLUTION. CAN YOU THINK OF SOME EXAMPLES ?

35. POSITIVES AND PROGRESS
Waste segregation and recycling is now common on many building sites
This not only cuts down on waste going to landfill but conserves energy, conserves natural resources and helps reduce greenhouse gas emissions e.g. CO2 caused by the manufacture of new materials

36. WASTE SEGREGATION
SEGREGATE TIMBER/PLASTIC/RUBBLE/PLASTERBOARD FOR RECYCLING ON-SITE

37. CONSTRUCTING NEW BUILDINGS
Measures are now in place to ensure that modern buildings are built with minimum environmental impact and are designed to be energy efficient during their life cycle

38. These include Life Cycle Assessments,
Environmental Impact Assessments,
Environmental Management Systems and
Government Legislation such as the Town and
Country Planning (EIA) (England and Wales)
Regulations 1999

39. QUESTIONS
Please feel free to ask any questions