It actually is special

Hempcrete's unique properties have led to widespread adaption across the world.  

It has thermal mass (think concrete, bricks or a hot water bottle) to maintain a stable temperature. And Interestingly, it's also insulative due to its porous, light composition, reducing energy loss whilst shielding from the harsh summer sun. These two properties work in tandem to outperform most current day wall systems whilst remaining low-tech, ecological and easy to install. Reducing electricity usage and dependence on air conditioning by tremendous margins. Its promise and interest are continually demonstrated in an ever growing body of research.

It actually is special

It's a high performance insulator and can be finished to suit both modern or period homes. It is an eminently carbon negative, natural and lightweight construction material which provides highly efficient temperature and moisture control among other unique characteristics; it is formable, dynamic, cures within hours and is one-seventh the weight of concrete.

Hempcrete.

Good for you
Good for the planet
Good for your home
Good
for
you
Save up to 80% on your bills
Hempcrete is one of the best insulative materials on the market. Your wallet will thank you.
Non-Toxic
No VOC’s (Volatile organic compounds) which harm human health
Forget about Asthma and other respiratory issues
It stabilises ambient humidity to the levels we’ve evolved to be healthy in.
A silent and calming home
Fantastic acoustic performance provides privacy and solidity in the home.
Mould and Bacteria resistant
Is intolerant to bacteria. Prevents mold, mildew, and rising damp. The lime binder petrifies the timber frame over time
No sick-building syndrome
Actively works against this phenomena, characterized by skin irritations, headache, and respiratory problems, thought to be caused by indoor pollutants, microorganisms and inadequate ventilation.
Breathable walls
Homely and comfortable. Never muggy and stuffy.
Good
for the
planet
Zero landfill
No wasted materials unlike conventional construction. All Hempcrete ends up in the walls, any leftovers can be laid out in the yard.
Negative carbon footprint
An average net saving of 53.5 tonnes of carbon for every house built (M. Berners-Lee 2010)
Co2 absorption x6
Hempcrete is made of the biomass of the Hemp Plant, a plant six times more effective than timber at storing carbon.
Good for your home
Firezone rated
Protects against, and is compliant to Australia's highest Bushfire Attack Level rated zones.
Hempcrete is a Super-insulator
Outperforms Hebel and other leading insulators.
Stable temperature
Has thermal Mass properties, storing heat-energy like bricks or stone.
Termite and rodent proof
Hempcrete is highly alkaline, rendering it inedible to both termites and rodents.
Stores heat
Outperforms Hebel and other leading insulators.
BCA Compliant
Conforms to all requirements set out by the Building Council of Australia and Victoria.
No wall draughts
No gaps, is a continuous unbroken building envelope.

Hempcrete.

Good for you
Good for the planet
Good for your home
Good for you
Save up to 80% on your bills
Non-Toxic
Mould and Bacteria resistant
Forget about Asthma and other respiratory issues
Breathable walls
A silent and calming home
No sick-building syndrome
Good for the planet
Zero landfill
Negative carbon footprint
Co2 absorption x6
Good for your home
Firezone rated
Hempcrete is a Super-insulator
Stable temperature
Termite and rodent proof
Stores heat
BCA Compliant
No wall draughts

What's the science behind it

There’s a great deal of science behind hempcrete.

Here I have collated, in plain English, what I believe to be the five most significant benefits of life in a Hemphome.
Regulates ambient humidity
Hempcrete has specific "breathability" properties. What this means is that Hemp Walls actively absorb and diffuse excess moisture. This is vitally important. Why? Because temperature isn’t the gold standard for warmth or comfort. It’s actually moisture.

You become colder a lot faster when moisture is present. Ever notice how quickly you freeze after leaving the pool or the shower? The more moisture present, the quicker heat conducts away from you. In fact, the reason your body sweats is to remove excess heat from the body. One of the gifts of Hempcrete to the industry is its strong moisture regulation and moisture buffering abilities. It protects us from the moisture spikes which modern houses are known for. Creating healthy, comfortable and stable temperatured homes.
Why is modern housing plagued by moisture issues? Because they’re essentially sealed units. The problem is that so many moisture generating activities occur inside of our houses. From cooking and bathing to human respiration; often with the moisture becoming trapped.

Many of us do not realise that Air-Con systems are designed in part to remove a good deal of excess moisture. Without that mechanical intervention, mold will occur. A good analogy to describe the issue is to think about what happens when you close a fridge and turn it off for a week.

So moisture is an issue, but how much are we talking about? Humans alone generate 115 to 270 grams of water per hour (2.8 to 6.5 kg per day) through respiration and perspiration (B.K. Kreiger and W.V. Srubar, 2019). Combined with the common issue of rising damp (moisture creeping up the footings) condensation and mold take root. This is catastrophic to the building fabric over time, in fact it is the number one cause of building failure today.
The holistic breathable moisture regulation abilities of Hempcrete allow the house to take care of you without mechanical intervention. It allows internal enclosures to a relative humidity that ranges between 40% to 60%, within which humans have evolved to find comfort. We naturally describe spaces with stable humidity as comfortable, whereas rooms with too much moisture always feel stuffy or damp.
No sick-building syndrome

“The conditions which encourage the growth of bacteria, moulds etc which affect both human and building fabric health are the same. If relative humidity is kept at between 40 and 60% then none of these viruses, moulds, fungi, bacteria can’t survive”

- Neil May “Traditional Materials & Energy efficiency”

Melbourne’s average annual relative humidity is 55.8%. The average monthly relative humidity ranges from 48% in January to 67% in June. So if the average relative humidity outside is safe for human health, why would we need a protective moisture barrier? One which inadvertently locks in and builds up moisture in the home and poses a threat to human health.

Sick building syndrome describes the phenomena in which time spent in a given building has a detrimental effect on ones health or comfort. Whether it’s physical issues such as headaches, skin, eyes, nose or throat irritations and asthma; or more just a general sense of stuffiness or chill. It is a phenomena which has become more and more prevalent as modern housing moves further from what we’re evolved to live with. 

A brief google will show that some of the major causes of asthma include dust mites and their faeces, moulds, spores, inorganic paint, adhesives and a wide range of organic compounds commonly found in overly moist or overly dry indoor environments.

Hempcrete and other natural building materials can address these concerns whilst also being a competitive and affordable material in the modern building industry.

Hempcrete is a low-emission material. It not only doesn’t "off-gas" or contribute to poor indoor air quality, it actually has an ability to moderate and effectively blunt the evening peaks of moisture over a 24 hour cycle. It’s large mass and strong cellulose have been shown to absorb and disperse volumes of moisture indefinitely without rotting. Furthermore, the lime binder - being highly alkaline - is a naturally occurring anti-fungal and anti-bacterial. 

Hempcrete naturally keeps us in the 40% - 60% golden zone. This is why occupants report a feeling of general comfort. Whereas homes with moisture issues feel like muggy tombs. 

Regulates ambient humidity

Thermal bridging is a fancy word for gap in your insulation. Heat will always pinpoint a gap and flow through rapidly. In a standard house, that expensive conditioned air escapes through a huge array of spots. For instance, it flows through voids for power-points, gaps between stud and insulation, empty eaves, the space between windows and the stud frame, wall corners where studwork meet, missed spots due to a hungover apprentice or behind the architraves and skirting boards. Basically anywhere where insulation isn't.

Why is this important in Australia? Because of unwanted heat. It simply flows in through these gaps. It’s a phenomenon in the Australian building industry as well understood as it is under documented. And it is the major reason for the significant performance-gap between estimated energy usage and actual costs of conditioning your finished house.

Hempcrete addresses this issue so well as it creates a complete insulative envelope. You’re creating a monolithic mass of continuous insulation which wraps around and encases the entire house frame.

Hempcrete is airtight, solid and eliminates wall draughts. This is hugely important because a complete thermal envelope of the house is created. In Australia, if we can avoid heat sneaking in by stopping building draughts or ‘thermal bridging’ we eliminate the largest contributing factor to heat entry and exit.

Thermal mass

Materials with thermal mass have the capacity to absorb, bank and release heat energy to delay temperature changes. In Italy, for example, marble banks up cool inside the home to cope with the hot Mediterranean climate. In the southern US, rammed earth shields from the scorching heat. Clay and cob homes proliferate in India and Africa. Here, in Australia, we envy those with the classic and stable mudbrick or bluestone homes which manage to keep the home cool. It's an age old technique to dampen temperature change in the home.

Flimsy modern houses lack thermal mass. They require our vigilant attention to keep windows and doors closed to preserve our precious expensive freshly conditioned air. In other words, only the air is conditioned, nothing is there to bank it up. 

The thermal mass of Hempcrete stabilises the home. Energy sinks into the walls and leaves you free to naturally ventilate your building. A huge bonus for hemp homes is the freedom to open the window if it gets a bit stuffy; safe in the knowledge that all your expensive conditioned heat is not going to flow straight out the door.

A Super-Insulator

To grasp the insulative abilities of Hempcrete best - and also to offer something more than the pop-science which proliferates the industry -  I’d like to simply break down some actual research from the engineering department at Ben-Gurion University in Beersheba, Israel. 

The researchers wanted to test the thermal performance of four separate one hundred square meter test dwellings with an interior ceiling height of 2.7m and three north facing windows.

What was found was that essentially even the most widely available, most highly reputed conventional leading energy efficient building material available in Australia, Hebel board, still would require almost 500 kWh more per year of energy than Hempcrete.

Moreover, when testing the ‘cheap’ option over the course of a year, the hollow-core brick used 6128 kWh more energy...

Hempcrete would require only 706 kWh per year, and only 13kWh of that being in the summer. The Air-con only switched briefly in the midst of heatwaves. The researchers also found that in winter the usage is almost half that of a Hebel-clad dwelling.

Simulated temperatures during summer period for passive building made of different materials

The graph represents the performance of Hempcrete during a midsummer week in scorching Israel. The energy consumption of the Hempcrete structure was the absolute lowest. Using Hempcrete instead of HCB (hollow core brick) can save almost 100% of the energy required for cooling and around 82% of the energy required for heating. Not only that, it was the building which was the most comfortable during those unbearable heat waves.

The energy consumption of the Hempcrete structure was ∼7 kWh/m2/year, which fits the highest standards of what is called ‘nZEB’ or a Nearly-Zero Energy Building.

It has also been shown that hempcrete floors (yes, you can hempcrete your sub-floor when paired with floorboards) when compared to a standard build up of R2.5 Polyester batts between floor joists would save an extra 1985 kWh per year, and chop almost an entire star off of the fabled (NatHERS) Australian star rating.

Health concerns and conclusion

The dust from Hebel board contains crystalline silica which is harmful when inhaled. The dust is vastly more minuscule than a grain of sand and therefore is often inhaled without knowing. Exposure to silica dust can lead to the development of lung cancer, silicosis (an irreversible scarring and stiffening of the lungs), kidney disease and chronic obstructive pulmonary disease. (cancer.org.au).

Expanded Polystyrene Board (EPS board on the above graph) on the other hand is an extremely lightweight product that is composed of expanded polystyrene beads. It’s the same substance as the cups and containers that might be used to house a Halal Snack Pack or a chips and gravy. It leaches toxins over time and is a petrochemical which when “burns, a kilogram of polystyrene will release more energy than a litre of petrol” according to the Victorian Building Authority.

Today we can choose to insulate our homes with a naturally grown, carbon sequestering carbon based lifeform which not only provides the best thermal comfort but also has a genuine positive impact on the environment. So why might we squander our time by kiln firing minerals at 1500C and adding a cornucopia of chemicals and foaming agents to create something which not only performs less efficiently, leeches chemicals into the dwelling but might also even cause a devastating house fire? 

Hempcrete and the environment

The impact of the construction industry on the environment is often overlooked. If you want to know more about how hempcrete, contributes to a healthier planet, visit our dedicated page.

Hempcrete and the environment

If you have any question about hempcrete, feel free to book a free consulation call with me or just call me when it better fits your schedule.

Proven method,
invaluable experience.

I’ve fine tuned the Hempcreting process with the leaders of industry in the UK to provide a higher standard of genuine sustainable housing right here in Australia.

Proven method,
invaluable experience.

I’ve fine tuned the Hempcreting process with the leaders of industry in the UK to provide a higher standard of genuine sustainable housing right here in Australia.