DESIGN OBJECTIVES AND RESPONSES TO CREATING THERMALLY COMFORTABLE HOMES FOR AUSTRALIA'S CLIMATE ZONES
Owner builders are often looking for affordable sustainable design options, as not everyone can afford to employ an architect or building designer. This website is a really useful starting point for anyone wanting to build a sustainable home
THE THERMAL PERFORMANCE OF HEMP LIME BUILDINGS
1. Hemp Lime Bio-composite as a Building Material in Irish Construction (2012) Patrick Daly, Paolo Ronchetti and Tom Woolley
The STRIVE report prepared for Ireland’s Environment Protection Agency collated a growing body of international research on hemp lime and reviewed its increasing application in construction, including some significant demonstration projects
2. Hygrothermal modelling of Lime-Hemp concrete used as a building material and indoor climate buffering characterisation, Dubois, S., Evrard, A., Lebeau, F
This study showed that LHC can be classified as having excellent moisture buffering performance and confirms the general idea of agro-sourced materials being good indoor climate regulators.
3. Transient hygrothermal behaviour of hemp lime materials Evrard, A PhD, Université Catholique De Louvain, 2008
“High inertia of LHM wall components allows them to dampen the effects of daily variation of outside climate, and to delay the effects of peak values or sudden variations. They also regulate the inside level of temperature and humidity (TBV and MBV).”
4. Thermographic Data - The British Research Establishment (BRE) and the Suffolk Housing Project
Comparative thermographic data was collected from the houses built for Suffolk Housing Society as part of a social housing development. The scheme involved the construction of eighteen dwellings, 16 of which were built using conventional masonry construction methods and materials and 2 of which were using Hemp Lime construction.
5. Interview with Ian Pritchett Chairman and Technical Director of Lime Technology in the UK
Interview about the characteristics of the material as a built element of a building including the vapour permeability and thermal insulation properties of hemp-lime building materials.
8. Tom Woolley & Rachel Bevan house build.flv
Architects Tom Woolley & Rachel Bevans show a video of their hempcrete house with an explanation of the low carbon, low energy materials for their build.
AHMC's building system stipulates rendering of all external Hemp lime walls with either AHMC's Hemp-lime Render or other Lime Renders. We also advise the use of an additional exterior coating of Waterglass (Sodium or Potassium Silicate Solution) which is a breathable, non-toxic fire-retardant and water repellant, increasing the longevity of natural finishes. Internally walls can either be clad, rendered with either breathable clay or lime renders, finished with lime washes or clay or mineral silicate paints, or kept as off-form feature walls and clear sealed with Waterglass which is also a breathable material.
1.AHMC 1 hour fire test on 10mm AHMC Hemp-lime rendered wall
In a documented fire test conducted in August 2019 no damage was observed in a 200mm thick, 10mm rendered hempcrete wall exposed to a 600mm high flame from a fire burning right against the wall for a period of 60 minutes.
"Providing all other aspects of the treatment of any building built in a bushfire prone area building are designed and detailed to comply with the accepted recommendations in relation to detailing and the use of non-combustible materials as set out in AS 3959 Construction of buildings in bushfire prone areas and a certified building process, 200-300mm hemp masonry, (dependant on BAL rating) otherwise known as hempcrete walls, can perform satisfactorily for use in bush fire prone areas to Bal 40 when rendered with 10mm lime render.
In full scale laboratory testing the temperature 60mm below the surface of a rendered hempcrete wall exposed to fire, was restricted to less than 100 oC, the temperature of boiling water, and far below the ignition temperature of pine which is over 400oC.
2. Hempcrete as a Fire Retardant Building Material – Steve Allin demonstrates hemp lime building material’s resistance to burning
3. Strive Report - Hemp lime bio-composite as Building Material in Irish Construction, Daly P., Ronchetti.P., and Wooley.T
Importantly the fire testing carried out to EN 1365-1 on a lightweight wall mix with timber frame infill indicates that 60 minutes fire resistance is possible. Given that masonry blocks are stronger and denser these may achieve similar or better levels of performance, depending on the performance of the mortar in particular given the finding of the 2007 Lime Technology Study.
4. The contribution of Lime Renders to the fire resistance of non-combustible Hemp lime walls
"Fire resistance and combustibility
Cementitious external rendering including the use of lime renders is classified as non-combustible when the organic material content is less than 1%. Where the organic material is greater than 1% the render should be tested and classified in accordance with BS EN 13501-1. A render contributes to the fire resistance of a wall, but generally no separate values are calculated for the rendering system." (AHMC's Hemp lime Render contains less than 1%organic material)
Educational guide to the properties of Rendering Mortar
5. Waterglass (Sodium and Potassium Silicate Solution) as a flame retardant additive for natural fibre reinforced composites
In this analysis the flame retardant effects of Waterglass on natural fibre composites are tested using fire testing categorisation according to DIN 53438 the European standard. "Composites impregnated with Waterglass fell into the best category K1 because the flame extinguishes by itself when the flame is taken away from the specimens"
6. The impacts of natural or 'legacy' household furnishings vs modern synthetic furnishings on fire behaviour in household fires
This video, made by NIST (National Institute of Standards and Testing) shows the danger of "modern" fires compared to the danger of fires occurring 40 years ago. Keep your eye on the clock.
CASE STUDY - Low Impact Materials – The Triangle, Northern Road, Swindon,
This Hemp Lime housing development comprises 16 two-bed houses, 13 three-bed houses, 7 four-bed houses, 4 one-bed apartments, and 2 two- bed apartments. There are homes for Intermediate Rent and Rent To Homebuy, as well as homes for affordable rent to local people registered with Swindon Borough Council.
SUSTAINABLE PROCUREMENT - THE IMPACTS OF INTERNATIONAL SHIPPING AND THE NEED TO SUPPORT AUSTRALIAN HEMP MANUFACTURING
1.Despite emissions exceeding those of Germany, the shipping industry remains outside any international agreement to limit its emissions. While policy is ultimately necessary, key actions should be taken by banks to begin steering the industry towards even preparing for decarbonisation.
Both the U.N.’s International Maritime Organization and the European Union are working towards greenhouse policies for international shipping, at least one of which will be implemented by 2023. Despite this being only a few years away, only two banks of the more than 40 active in shipping consider the efficiency of ships they finance."
2. Impacts of shipping in the South-East Marine Region of Australia
"The major hazard associated with the discharge of contaminated ballast water is the introduction of exotic marine species to the local marine environment, and translocations of existing marine pests to new locations (for example, transporting the North Pacific sea–star from Tasmanian waters to mainland waters)
Establishment of exotic species can cause the alteration of entire ecosystems and habitat and the extinction of indigenous species by predation or competition (ANZECC, 1996a). The effects of introduced species increase with time and are generally irreversible.
Introduced marine species include fish, invertebrates, and seaweeds. 9 Exotic marine species that can be attributed to ballast water, and are of particular concern in the South-east Marine Region, are listed in Table 2.1."
3. In Western Australian waters, there are 60 known non-native marine species that have become established. Most are temperate species, with only six that are exclusively tropical. The greatest number of introduced species is found in the south-west corner of the State – 46 in Perth and Fremantle waters, 25 in Albany and 24 in Bunbury.
Unlike many other types of environmental impacts, invasions of introduced marine species can be irreversible.
4. "As well as contributing to global warming ... ship pollution includes toxic compounds and particles that cause a host of other health hazards. A 2016 Chinese-led study found the shipping boom in east Asia has caused tens of thousands of premature deaths a year, largely from heart and lung disease and cancer.
When diesel ship engines burn poor-quality fuel, their smoke stacks release oxides of nitrogen and sulfur as well as carbon. These pollutants, as well as contributing to greenhouse warming, are highly toxic. Sulfur dioxide readily dissolves in water, creating acid rain that causes harm to both people and the environment."
5. "India, Bangladesh, and Pakistan are popular for ship scrapping. In Bangladesh for example, 40,000 mangroves — trees that stabilize many tropical coasts and are habitats and breeding grounds for many species — were chopped down in 2009 alone to accommodate shipbreaking yards. The pollution from scrapping there has caused an estimated 21 fish and crustacean species to become extinct. And reportedly, each week one worker dies and seven are injured in the scrap yards of Bangladesh."
6. "The IMO found that international shipping contributes about 13% and 12% of annual global NOx and SOx emissions, respectively, from anthropogenic sources reported in the latest IPCC Assessment Report (AR5).
This sector contributed an average of 2.6% of global annual CO2 emissions from the combustion of fossil fuels during the period 2007 – 2012. (The figure for 2012 was 2.2%.)
The IMO also found that shipping CO2 emissions are projected to increase by 50% to 250% in the period to 2050, despite fleet average efficiency improvements of about 40%, because of the expected growth in shipping activity."
7." The 2006 Maritime labour Convention established universal rights for seafarers, but they remain among the most vulnerable group of workers. There’s not much access to lawyers and doctors at sea and the practice of registering ships under flag states with lower human-rights standards persists.