Rammed earth in New Zealand

I recently visited Pompallier House in Russell, New Zealand.

This amazing rammed earth building was built in the Beautiful Bay of Islands in 1842 to house a printing press for the recently established French Roman Catholic mission in Oceania. 

Kororareka (literally 'How sweet is the penguin'), later known as Russell, was the first major European settlement in New Zealand. The settlement became a centre for whalers and for European speculators who traded with the local Maori population. First settled by Europeans around 1820, with James Busby appointed by the Crown as 'British Resident' to maintain order,  by 1830 the place had become known as 'The Hellhole of the Pacific'. 

In Europe, Pope Gregory XVI charged the Marists, a French religious institute founded in 1816 with the task of bringing Catholicism to Oceania. The Marists chose Bishop Jean Baptiste François Pompallier who picked Kororareka as his base for Evangelising the South Pacific. 


Jean-Baptiste François Pompallier

In 1838, Bishop Jean-Baptiste François Pompallier arrived in Kororareka, having established missions across the Pacific, and set up the mission as the Church's administrative centre for one sixth of the earth's surface. Energetic Pompallier travelled widely around New Zealand and the South Pacific, and attended the Treaty negotiations between the Maori and the British. Pompallier was present at the signing of the treaty of Waitangi, and asked for 'free tolerance in matters of faith' to be included in the treaty, ensuring his Church's right to remain in the country. 

The spread of Christianity across the South Pacific turned into an arms race between the English Protestants and the European Catholics, with each competing to provide Bibles, books and pamphlets.

"...today we are told that the Protest[ant] missionaries should soon receive six to eight thousand Maori Bibles to be distributed to the natives; it’s only a few weeks since they received a complete shipload of blankets."

Letter from Fr Antoine Garin to Fr Colin, Kororareka, 19 January 1842

Pompallier decided that to get ahead, a printing press was required in Kororareka, and in 1840 sent to France for a printer and an architect. 

Louis Perret

In September 1841 successful French architect Loius Perret travelled from Lyon to Russell at the invitation of Bishop Pompallier. At this time the Mission appeared to comprise a number of timber buildings, around the garden of the existing plot. Perret had worked with French architect Jean-Baptiste Rondelet in the Lyon area, and one of Rondelet's techniques was the newly rediscovered technique of rammed earth.

Rammed earth in the early 19th century 

Rammed earth is a construction technique of compacting soil between removable formwork board to create a homogeneous solid wall. The technique, common in medieval Spain, and southern France, was 'rediscovered' by Frenchman Francois Cointeraux. Cointeraux published a series of pamphlets in 1793, around the time of the French Revolution, proposing rammed earth as a method of home construction for the masses. These pamphlets led to a brief building boom at the turn of the century, and spawned a number of similar publications. One such publication was Jean-Baptiste Rondelet's book Traite Theorique et Practique du l'Art de Batir published in 1812. 

The first rammed earth building in New Zealand

Perret saw the poverty of the community, and proposed rammed earth (Pise in French) for the construction of the newly proposed print works at the Mission, utilising soil from the site and negating the need to buy significant amounts of timber.

The formwork used for the building was similar to that proposed by Rondelet, and replica form work was made for the restoration of the walls in 1994.

There is evidence that the Brothers used crushed shells from the adjacent beach, which they will have burned to produce hydraulic lime. This lime does two things, it hydrates (reacts with the water) which uses up some of the water in the wall, and this hydration causes a cementing paste to form and harden. With enough lime in the mix, you get a material similar to concrete, and with small amounts of lime the walls behave more like a robust sandcastle.

It seems that the Antipodean soils were different to those of Lyon, and the methods proposed by Rondelet did not transfer so well to the Pacific. The rammed earth walls were not considered a great success.  

Only the ground floor is constructed in rammed earth,  while the upper floors are made using wattle and daub, and the roof is timber. It is suggested that this is because Bishop Pompallier and the missionaries did not have enough money to buy the materials for the ground floor. 

"We have a printing press and no place to set it up; no way of building one, no timber, no money to get it. What’s to be done? Stay here until we have received money! But building in pisé could be done without money, but how much effort and time (will be needed)! Already the pisé is rising on the foundations, but as Father Epalle often says (in everything that happens to us he is always Father), this pisé splits, cracks everywhere. The principles of Rondelet are not based on antipodean clay: a clay which was thought to be very good is now seen to be very bad. Well, we’re in God’s hands! We say meanwhile, “Little by little the bird builds its nest”. We will be happy if in six or eight months the press can clank."

Letter from Fr Antoine Garin to Fr Colin, Kororareka, 19 January 1842

Perret directed the Brothers in the rammed earth technique, but life was too tough for this Lyonaise architect, and he stayed in Russell for only 6 months, returning to France at the end of the summer in May 1842.  

"Mr Perret who does a bit of medical work and wants to go back to France, and three or four Brothers employed in building a fairly big house in pise, which seemed to me to be not particularly solidly built. The Bishop has been away for 12 months. He is in the islands of the tropics. The mission is in the most awful misery. Our poor Brother have suffered a lot, and I know some who have gone like savages to ask for some pieces of biscuits from foreign ships passing by."

Letter from Fr Forest to Fr Colin, Bay of Islands, June 1842

Was it a good idea? 

The ground floor of the new printing press is rammed earth, but we get the impression that as soon as they could, the brothers switched to alternative timber construction. 

I would argue that the soils used for the building were Expansive, meaning they change in volume depending on the water content. As directed by Rondelet, the soils will have been compacted close to their Optimum Water content, probably around 25% of water by volume. The walls will dry back to a moisture content of around 2%, and as the soils dry they shrink and crack, just as described by Fr Garin. The typical Lyon soils are not expansive, which is why the rammed earth technique became popular in France. The stabilisation of the soil using the burned lime shells is likely to have reduced the expansive effects, but as the letters show, there was still significant cracking. 

The change to more expensive timber, presumably which occurred after Mr Perret left for France, would have been an additional cost for the community, but one justified because it was obvious the rammed earth was not working so well. The upper storey of the building has a timber frame, with wattle and daub type infill panels. The earth plasters used for wattle and daub can shrink and crack, but supported on a timber frame, the upper part of the building is unaffected.  

A history of Pompallier House

The building work was completed in 1842, and began to produce the first Maori translations of religious texts. 

Maori leader Hōne Heke spared the building when he sacked Kororāreka in 1845.

A number of other buildings including a chapel and a kitchen were constructed on the site to expand the compound, but rammed earth was not used for any of these buildings. 

The building was used as a tannery, and tanning pits were dug at the rear of the building, and in 1850 the Marist mission headquarters moved to Auckland, and the building was sold to James Callaghan, who converted it into a family home which became known as Callaghan's Castle. The building passed through private ownership of the Greenway and Stephenson families. The house was significantly altered, with a timber frame added to the outside of the building, and it was gradually turned into a grand faux Victorian house with accompanying gardens. 

The New Zealand government bought the building in the early 1940s. Concrete repairs were added, but these appear to have been unsuccessful and the building was eventually closed for refurbishment. 

Pompallier House now

The building underwent extensive renovation and reopened in 1993. The house is now run by Heritage New Zealand and is open to the public. The original printing press has been reinstalled, and the building largely returned to its original configuration, with the gardens typically later Victorian and Edwardian. It is well worth a visit. 

 Extract from Rondelets book, showing a rammed earth house.  Source

Extract from Rondelets book, showing a rammed earth house. Source

A massive thanks to those who have put together the Marist Studies Wiki, which I have used extensively in researching this article. 

10 thoughts about The International Straw Bale Conference 2016

I've just returned from the amazing International Straw Bale Conference 2016, in Methven, a ski resort on the South Island of New Zealand. The conference brought together enthusiasts for Straw bale and earthen building. Here are 10 things I learned:

1.  20% of the participants were international, and 80% Kiwi. This is great for New Zealand sustainable building, but also great to see so many people willing to travel to talk about straw bale building. We were very privileged to hear some amazing speakers from Europe, North and South America. 

2. The mix of participants was fantastic. Straw bale building events can be predominantly tree hugging hippies, but that wasn't really the case. The participants included from property developers, building officials, architects, engineers, product sellers, as well as students and academics. 

3. It was great to see mainstream product manufacturers exhibiting. Rockcote, Terra Lana and BBS Timbers are definitely suppliers to the general construction industry and show that straw and earth building are entering the mainstream. 

4. There is a superb resource of 'Old Guard' practitioners, who have been doing this since the 1970s. These experts have so much experience to offer and it's so great to learn from them and not reinvent the wheel. 

5. I talked about innovation, and it's great to see so many different types of earth and straw building, all in one place, and from practitioners from all over the world. There are many ways to work with earth and straw, and we should find the best solution for the situation.

6. The things we talked about are the same things which were talked about 30 years ago.  

7. There is a wide range of projects, of varying sizes and each with its unique set of challenges. What the walls of the building are made of is a reasonably small part of the overall project.  

8. Cohousing communities such as LILAC in Leeds and Earthsong in Auckland are good, and great for the people in the community. But I don't feel they will necessarily take straw and earth building into the mainstream, and a slightly different, perhaps developer led financial model might be necessary to take natural building into the mainstream.

9. The group of people attending the conference are predisposed to loving straw, and given the chance would live in a straw or earth house. The rest of the world, would, given the chance, live in a 'Sustainable' home. We can make these sustainable homes. This applies especially in the developed world to the baby boom generation who are retiring and downsizing, and to the Millennials and Generation Y who are the new home buyers. 

10. There are regulatory hurdles. These Building Code regulations exist for good reason, and we must meet them with natural building materials. Meeting the standards can be a tough hurdle, but using experience gained on previous projects makes this progressively easier. 

A massive thanks to Min Hall and the organising team, and to the army of helpers during the conference. 

I gave presentations about Innovation and about Standards, and 5 minutes about the science of liquid bridges which you can download below.

Innovation in Earth Building PDF

Standards in Earth Building PDF

5 in 5 Science of Liquid Bridges PDF 

Earthquake in Nepal

A 7.9 magnitude earthquake has just hit 80km west of Pokara in Nepal, with reports of damage to many buildings in Kathmandu. The quake was felt heavily in Delhi, and across much of the Himalayan region.  Reports of casualties are yet to come in, but comparisons with recent similar quakes would indicate we could expect thousands of fatalities. 

Initial social media reports suggest that more modern reinforced concrete buildings have fared reasonably well, though there has been significant damage, the buildings have not completely collapsed. The 19th century Bhimsen Tower appears have have been completely destroyed, and there are reports of the non-engineered homes being heavily damaged and collapsing.

Information is coming out of Kathmandu, but there is currently less news from Pokara and the towns in the Kathmandu valley, both closer to the epicentre of the quake and where there are significantly more non-engineered buildings, and thus we would expect more casualties.  

The possibility of a quake in Kathmandu has long been anticipated, and there are plans in place for this event. Records indicate a major earthquake around once every 75 years, with the last major earthquake in 1934 (81 years ago). The Kathmandu Valley earthquake Risk Management Plan (http://geohaz.org/projects/kathmandu.html) completed in 1999 assessed the risks and aimed to mitigate the damage to the region.

Earthquake resistant construction techniques were taught (and known about prior to the inception of the project), and I must presume that many of the buildings constructed more recently will have behaved adequately in this earthquake. The older building stock may not have been so resistant to an earthquake of this magnitude. 

Now is the time to focus on the emergency works, to first rescue survivors, then to provide Water, food, sanitation and safe shelter to those who require it.

Once these priorities are met, the international community must look to retrofit of existing buildings, or to the demolition of buildings which would be unsafe in an earthquake of this magnitude. This process is well underway in New Zealand, following the 2011 Christchurch earthquake, it is costly and painful, but ultimately the assessment and improvement of earthquake prone buildings will save many thousands of lives. 


Disclaimer: I wasn't involved in the Kathmandu project, but I have visited this region. I'm a structural engineer working in New Zealand, with an expertise in mud brick construction. 

 Durbar Square in Central Kathmandu     https://twitter.com/bjpsudhanrss/status/591879677574139904
 Durbar Square in central Kathmandu     https://twitter.com/bjpsudhanrss/status/591879677574139904
 Durbar Square in central Kathmandu in happier times

Durbar Square in central Kathmandu in happier times

IREC Conference writeup

Two weeks ago I attended the excellent 1st International  Rammed Earth Conference in Perth, Western Australia. This was the result of 18 months hard work by Dr Daniela Ciancio and Dr Chris Beckett, who are heavily involved in research at the University of Western Australia in Perth. 

The conference was a meeting of rammed earth contractors, designers and researchers from all over the world who met to discuss the finer points of rammed earth for four days. I was in my element.  

Perth, and Western Australia are held up as an example of the best of stabilised rammed earth construction, and we were able to visit the fantastic Church in Margaret River, and some wineries with rammed earth buildings. It's clear that Stephen Dobson and his contemporaries have carved a superb rammed earth niche in this corner of Australia.  

We were also treated to David And Taj Easton from Rammed Earth works and Watershed Materials. David has been at the forefront of earth building for over 30 years, and continues to innovate with new materials and techniques, as his collaboration with Joe Dahmen in Watershed block really shows.  

Meror Krayenhoff has revolutionised rammed earth building in colder climates through his SIREWALL system of insulation between rammed earth leaves, and Meror shared his experiences and visions using this system.  

The conference also featured many speakers exploring the thermal and humidity behaviour of rammed earth.  There is an amazing body of work exploring the hygrothermal  mechanisms at play in rammed earth. It is through understanding and measuring these mechanisms that we are able to use the material most effectively. 

There were a selection of papers on taking rammed earth buildings through the building consent process, with speakers sharing their experiences in Canada, the UK, Australia and New Zealand, with a wide range of experiences from remarkable simplicity to years of drawn out negotiations. 

My overwhelming thoughts at the conference were of optimism for rammed earth building, a commitment to maximising and improving the sustainable credentials of rammed earth, but an acknowledgement that further research is required to better understand the predict the behaviour of rammed earth.

Official conference website

 Participants at the 1st International Conference on Rammed Earth Construction. 

Participants at the 1st International Conference on Rammed Earth Construction. 

I certainly picked up that rammed earth has the ability to transform to suit the environment in which it is built. This was shown by a fantastic presentation from Rongrong Hu whose amazing work at Xi'an University who showed the variations in rammed earth across China, where the rammed earth wall thickness appears to change depending on the climate, and where in warmer climates, one of the walls is replaced by light timber framing.

This versatility is also found in modern rammed earth, exemplified by  the different approaches of David Easton in California and Meror Krayenhoff in the colder British Columbia whose SIREWall system places insulation between two leaves of rammed earth. 

I'm a structural engineer, and we learned from Bill Smalley how engineers in Western Australia have treated rammed earth, and from Tim Krahn about his experiences with structural engineering in Canada. There is still room for improvement in the structural understanding of rammed earth, and the large scale tests carried out by Daniela Ciancio and Chris Beckett at UWA, and by Venkatarama Reddy and his team in Bangalore are really pushing forward the understanding of rammed earth as a building material. On the modelling front, Quoc Bao Bui showed cutting edge Discrete Element Method analysese of rammed earth and looked at the creep behaviour of rammed earth. 

At the other end of the scale, the microstructural behaviour of rammed earth is being researched by the team at Durham using their new X-Ray Computer Tomography machine, and we were treated to exciting presentation about the inside of rammed earth from Joe Smith.

Perhaps the most inspiring presentation was from Joe Dahmen who showed some new innovations which might be worked into rammed earth, such as using microorganisms to grown cementing compounds at Biomason and  I also like the the 3D printed blocks which Ron Rael has recently produced. 

I'm really excited about the direction rammed earth building seems to be heading. There is still plenty of research and learning to be done, but there are also those who have been successfully building rammed earth for nearly 30 years. The material with a rich and varied past has a great future ahead.


Historic Rammed Earth through the ages

I'm going to start putting www.historicrammedearth.co.uk back together.

As I start, I thought it would be good to see how the website has developed since I first started it during my PhD. I don't remember when I first started writing some html, sometime in late 2004 -   probably about the same time Thefacebook.com started! 

All these sites are from the Wayback machine - https://archive.org/web/ 

IREC Conference

Photographs from the recent International Conference on Rammed Earth Construction

Our First International Conference on Rammed Earth Construction (ICREC2015) recently hosted by The University of Western Australia from 10 to 13 February 2015 was a major success with participants from 12 countries (Australia, Colorado, California, Brazil, Canada, South Africa, India, China, Uk, France, New Zealand, Italy) and representatives from the research (scientists, professors, students) and industry world (engineers, architects, builders).
We believe we found some answers, or ways to find those answers, but many questions are still open for discussion for the 2nd International Conference on Rammed Earth Construction in 2017 (ICREC2017), whose location is currently under evaluation.