Living for tomorrow, today...

Bottles for underfloor insulation

bottle floor

glass bottles as underfloor insulation

One of the key features of earthship is their use of waste materials in construction such as tires, bottles, cans etc. In the Waiheke earthship we are going to use bottles as underfloor insulation.  We haven’t heard of any other earthships doing this, however it fits into the whole earthship ethos so I’m surprised that its not part of Mike Reynolds approach.  The bottles will be laid on their side in a bed of sand over the  damp proof membrane.  Another layer of sand will cover the bottles and the spaces between them, and then a concrete pad poured over the top.  On top of this we are going to have an earth floor for a more giving and comfortable feeling underfoot than a hard concrete finish.

According to our architect Graeme North, preliminary calculated R values for 100mm thick concrete floors insulated underneath with bottles laid in dense sand is approx. 1.65 m2oC/W  and with bottles laid in pumice sand is approx. 2.06 m2oC/W.

This ignores the R value of the earth underneath the slab which varies according to floor perimeter length and with any edge insulation.

These figures have not been fully checked, and are calculated first order assumptions only, with considerable margin for error.  The  actual insulation values can only be proved by testing.


Waiheke earthship update

w elevationMany of you may be wondering if the Waiheke earthship is still going ahead. We’re pleased to say that after a period of regrouping we’re now moving ahead with the detailed design and hope to have building plans ready to submit to Council in the new year. We looked into the Kickstarter project for a NZ version of the global model earthship however after review and assessment of interest from the ES community we realised this would cost more than we’d be likely to raise through crowdfunding and not worth the effort. So we are going ahead with our own custom design which is a split level 3 bedroom earthship. The lower level is a standard global model with greenhouse on front but the top level is more open with a rear tyre wall but no greenhouse on the front. That’s because we want the living area to have large sliding doors opening straight out into a deck. This will reduce the thermal performance of the building in some ways however with Waiheke’s mild climate we’re willing to make that compromise. And if additional heating or cooling is required we also have some very innovative and first of it’s kind alternative technologies to draw upon from Dana’s energy company, Energy Alternatives. We’ll be posting more regular updates from now on as we make key design decisions and look to having a building schedule posted early in the new year.

Natural Building Conference and Tour

The Earth Building Association of NZ (EBANZ) invites you to their annual

“Natural Building Conference”.

 Labour weekend: Saturday 25th October and Sunday 26th October 2014 on the Kapiti Coast

(Optional: Monday 27 October 2014 in Wellington)

 Come along to meet fellow natural building enthusiasts and share a wonderful weekend.


             Visit at least eight spectacular homes that are constructed using a range of building techniques.
Listen to the owners/ designers talk about their building experiences.

             See practical demonstrations on:

o   rammed earth construction

o   light earth infill panels

o   homemade natural paints

o   and adobe brick testing

             Listen to our keynote speakers Professors Robert and Brenda Vale from the School of Architecture at Victoria University and authors of “Time To Eat The Dog” and “The Autonomous House”.

             Be shown around a permaculture garden by Emily Williams one of New Zealand’s permaculture experts

             Hear presentations on a range of sustainable building practices.

             Join a “show and tell” session, where participants can share their natural building stories in a short, punchy format

             Question the “ask the experts” panel, led by some of New Zealand’s most experienced natural builders and eco designers

             Get an update on the “New Zealand Earth Building Standards” revision

             Network with experienced owner builders and building professionals

             Share meals, accommodation and socialise with like-minded people during this information packed weekend


To find out more, register and book your accommodation today




Or call Verena on ph: 03 5450240

Auckland Council committee supports Earthship concept

pic of willWill Ilolhia gave a presentation recently (9 July 2014) to the Auckland Council Environment, Climate Change and Natural Heritage Committee about Earthships where they moved to support the ‘Earthship Biotechture’ concept and forward the presentation to relevant Council committees and departments (e.g Housing Project Office), Local Boards and Independent Maori Statutory Board for their consideration.

A copy of Wills presentation has been placed on the official minutes and is available on the Auckland Council website as a minutes attachment.
Fantastic to see a team of people of Maori and Pacific descent heading off to Taos to attend the Earthship Academy and plans afoot to build prototype earthships in Tonga, Samoa and Cook Islands.


Up coming Earthship workshop


rosa poster

This workshop will take place on a beautiful 10 acre property near Dunedin, New Zealand. Two 10sq m vaulted pods for food storage and a tool shed.

What we will be doing/learning - We will be taking this build from pounding tyres onwards. We will be working with the Earthship Biotecture principals, focusing on: thermal mass, building with recycled materials, water harvesting and power generation. There will be chances to get your hands dirty and ask all the questions you have to the experienced team.

More specifically you will get a chance to learn and build steel vaults, bond beams, do glass bottle work, tyre pounding, water catchment, laying cans for form work, insulation and drainage behind a tyre wall, mix concrete, cob work, natural plasters, lime render and more!

Shared learning - The intention is to create a place for the meeting of like minded people  - as well as learning building skills its a place to share knowledge and skills across all topics. Its about cooking,working, learning and celebrating together. Bring instruments, inspiring books and anything to add to a vibrant space.

Positions available: Earthships are a more recent building style, there are only a few kiwis who have been through the Earthship Academy training in Taos, USA and subsequent builds. As well as positions for 15 students, there are 3 places for experienced natural builders (or aspiring natural builders) to join the team, for the experience and food. This could very possibly lead to being hired for the next project, as the team is growing! Please state when you apply, if you’re applying for this position.

The other position avaliable is for a local Dunedin person to join the team as cook (sourcing local food, pick ups and organising breakfast and lunch) to keep everyone fed, watered and energised.

For an application form please flick me an email at 


This is a Sculpted Earth Project –

All info here at




Mini docco of a Kiwi Earthship Builder

In the middle of last year, I received a phone call from an enthusiastic talented film maker named Lu Davidson from the Inspiring Stories Trust. I was, she said, her first choice pick for a film after I was nominated for BeCause – a site show casing talented young kiwis.

Massive thanks to Lu and her partner Mike, who came to Christchurch to film (and help out) on the finishing touches of the miniship that I started there earlier that year with Michael Reynolds on his Christchurch seminar tour. Also thanks to the Inspiring Stories Trust for believing in young kiwis and showing our work to the world.



Any questions or comments please email



Earthing the earthship – NZ style!

Meeting at Graemes

Dana Darwin, Graeme North, Harriet Pilkington and Elvon Young discussing the design brief for NZ model earthship

Following on from the last update about the Waiheke Earthship and the positive responses we received for the crowdfunding idea, we are  now doing further ground work to scope out what “generic” earthship components such as  tyre wall structure, greywater recycling systems, water proofing and ventilation can be designed as a set of standard details and specifications that meet the relevant provisions of the NZ Building Code and can be tested for code compliance by way of an application to MBIE (Ministry of Business, Innovation and Employment).  Having this framework in place, would dramatically reduce the input required of professional engineers and architects in the design and consenting process of any particular earthship building in NZ in the future.

We’ve drafting up a design brief for developing  a NZ standard  earthship design and details adapted for the NZ environment and planning context.  Our process would include modelling to optimise the thermal performance of a global model earthship in the NZ climate and “earth the earthship” by using less cans, less cement and incorporating  more earth building techniques.  Currently as there are no approved standards for tyre walls etc, everything is “out of the box” and each and every earthship requires design work by architects and engineers which costs a bomb!.  At least this way we could all pitch in and pay once for the work to be done which will benefit everyone who wants to build an earthship in the future.

Please note that the Waiheke earthship is a unique piece of design work altogether.  We have already realized that our earthship tyre wall design, along with other factors, is unique due to our site circumstances and house design and not neccessarily the easiest and most cost effective method for most sites.

Once we have ironed out some more of the details and the cost to engage architects and engineers to do this work, we’re looking to invite the NZ earthship community to come together to help finance the project though a crowdfunding platform such as Kickstarter or Pledgeme.  Our intention is to lay the foundations for an earthship uprising!.  Together we can be the change we want to see in the world (well at least in our small corner of it), and create a template for low cost sustainable building in Aotearoa. 



Finishing work on Earthship Ironban, Adelaide. Part 1

Martin Freney and his wife Zoe have embarked on the adventure of building an Earthship on their piece of land in the adelaide hills, to run as a B&B. This is to give people the experience of living in an Earthship, be it for a short time, and also for Martin to continue his Phd research on constant temperatures inside earth buildings.

This building has reached lock up stage, and finishing touches will happen in spring. Resently I was there for a month to help run a crew and interns on renders, bottle walls, hemp work and building the planter.


Martin and Zoe chose to have natural renders inside their Earthship, which which are both earth and lime renders.

Earth renders are a mix of clay, sand and straw (final layers can use wheat paste or casein instead of straw). To prepeare, this, we soaked onsite clay (which was very rich, orange beautiful subsoil, we were extremely lucky there!) in barrels mixed with an electric mixer (left).

For cob work (pack out of tires or bottle walls) this is mixed 1:3 with sand and 1 part straw. It is then foot stomped on a tarp as its heavy and sticky, pulling the ends of the tarp into the centre to help roll the mix over and over. Cob can be left in this form until needed, it doesnt harden or go off, but may need a little added water to suit.

Layers on the wall: The tires need to be packed out in stages, to bring the walls flat. Between each layer we wet the wall, and also brushed on a clay slip (very watered down clay slurry) for best adhesion. The next layer is only applied when the previous is dry. Then we started using trawls to apply the render, wood or steel, and we used a rough float or scratcher to keep the surface textured for the next coat. For the render  we added clay 1:3 with fine blond plasterers sand, and half part fine chopped straw (run over with a lawn mower). Coats get thinner as you get toward your final layer, usually 3 coats are needed.












Niches can also be made with cob (right). 




DSC_1831Lime render is a mixture of slaked lime (powered hydrated lime, soaked in water for 3 months or more), sand, and option of straw.

Mixing render: we used 1:2.5 lime to fine plasters sand. It needs to be mixed well, with an electric mixer and needs to be thick enough it sticks to your trowel if turned upside down. Skin and eyes need to be protected well at all times!

Application: We did one layer of render, on top of cement plaster (underside of vault, arch beam and bottle walls). We sprayed lime water on the wall first – this is the water sitting ontop of the slaking lime, or lime putty mixed 1:60 with water. We applied the render with steel trowls and floated with a sponge to blend the lines as it was setting fast. Strait lime plaster gave us a beautiful light shade, which we used on the ceiling and we will use sandstone colored oxide in other interior finishes where humidity will be a factor.

Lime can easily colored by oxides – Test patches on the buttress (above)









 Thanks to everyone involved in this project, a wonderful example of a permitted ‘simple survival’ model Earthship in Australasia, and showing the possibility of an ‘owner builder’ designing and running the project on their own land. Pioneering work is very important, though often more time consuming and expensive, where we are all learning what to do and what not to, smoothing out design complications, testing materials and seeing just how many man hours go into the building. Thanks Martin and Zoe for hosting the community of builders and interns and sharing your project with us!

Part two, three and four will be on bottle wall construction, working with hemp as insulation, and building a grey water cell.

Words and images by Rosa Henderson. All questions and comments email