Archived Entries - Construction
- Home
- Blog
- Archived Entries
- Construction
Hemp and The Construction Industry: Will it ever break the mould?
When we think hemp, it is likely that an image of sandal wearing caftan clad teenager's springs to mind. However, think again; beyond this stereotypical image of a plant more associated with the psychedelic 1960's, hemp can contribute toward a healthy diet (Omega 3) and can be used as a cotton substitute in ecologically sound clothing and bedding. For the construction industry, it is a material that has been employed for many hundreds of years but has never quite made it as a mainstream construction material. The question that springs to mind is why should this be so?
A hemp crop can be grown without the use of herbicides or insecticides and can produce up to 4 tonnes of material per acre per year. Processing hemp results in two materials; hurds and fibres, both of which have properties that make them extremely useful in building construction.
Compressed hurds can be used in the creation of fibreboard, roofing tiles, insulation and bricks. Foundations can be made out of hemp hurds "hempcrete" when combined with lime, sand, plaster, some cement and water. A 6th Century hemp-reinforced bridge found in France is testimony to its stone-like strength and durability.
More recent examples of its use include 2 experimental homes built in Bury St Edmunds by the Suffolk Housing Society. Its purpose was to compare its energy efficiency and general performance against traditional materials. A subsequent report was issued by the Building Research Establishment in 2002 which compared the hemp houses against the traditional material built houses and its principal conclusions were:-
"Hemp houses have far less impact on the environment - they use less energy to build, create less waste and take less fuel to heat; albeit they cost about 10% more to build than a brick and block house".
Whilst hemp offers many qualities, it appears that it cannot compete with modern day materials on one key factor and that being cost. In a capitalist society, cost rules and until this is redressed, hemp will remain a fringe material better known for associations other than construction.
The True Cost of Buildings - How the Construction Industry must face up to its environmental responsibility
Did you realise that 47% of the UK's carbon emissions are from buildings?
The construction industry faces a massive challenge in helping the Government meet its target of reducing carbon emissions by 80% by 2050.
According to the Federation of Master Builders:-
- Construction uses approximately 6 tonnes of materials for every year man, woman and child in the UK
- Construction and demolition produce more than 80 million tonnes of waste each year -10% of which is unused in building materials
- 50% of the UK's energy consumption results from construction (10%) or during the life of the building (over 40%)
- 47% of UK carbon emissions are from servicing buildings
The facts speak for themselves and the construction industry must face up to its responsibilities of reducing both waste and carbon emissions.
In its defence, change is beginning to take with many bold initiatives being rolled out including small hydro electricity generators or straw bale technology for example.
Who knows, one day, the straw bale house may no longer be the preserve of fairy tales.
