Architect Graeme North, 65, known as the father of earth building in New Zealand, built his Warkworth home out of mud. He is saddened New Zealanders have been so slow to use natural materials to build their homes.

1 You've designed and built hundreds of earth buildings nationwide since the 1970s: how do people respond to them?

A calmness seems to come across people. There's a different quality about the light, the air, the acoustics that's hard to define. There's a warmth to them but it isn't just what you measure on a thermometer. They actually feel alive, like life is happening in them. The great thing about earth houses is the mass of the earth moderates heat and humidity so you end up with a drier and more evenly-temperatured house. Not like a stick house where the heat's only in the air, which takes much longer to heat. If you want to get moisture out of your air, bung in some earth plasters.

2 What are the top five questions you get about earth buildings?

"Will earth walls wash away in the rain?" No. "Will they fall over in an earthquake?" No. "Can I spill a glass of water on the floor?" Yes. "Can I paint it?" Yes. "What if my kid took a hammer to the wall?" Well, what would happen if they took a hammer to the walls of your current house? I made my own earth floor 15 years ago out of earth from our duck pond. After it was plastered and dried we flooded it with linseed oil and it's formed this really tough, durable surface which you can mop just like a timber floor. The only real damage it suffered was when a friend came to a party in stiletto heels.


3 Why don't New Zealanders use more natural materials?

I wish I knew. Part of the impediment is lack of familiarity. Another fear is resale value. The Auckland housing market is not about places where people live. It's about property values.

4 How can city dwellers access natural materials if they don't have their own duck pond?

I'd love to be able to see materials like untreated timber, earth plaster and mud bricks sold in mainstream building supplies stores. Auckland is sitting on millions of tonnes of clay. Most building sites are trying to get rid of it.

5 Have you always built stuff?

Yeah, growing up Lower Hutt my favourite present was a pound of nails. I'd spend hours banging them into the coal box. Drove the neighbours mad. The inside was like an iron maiden. Dad was a practical man so I'd follow him around, and a drainlayer I called "man". To this day I could still lay an earthenware drain from hours watching him. I decided to be an architect at age 13 when I saw pictures of Le Corbusier's work in Time magazine.

6 When did you build your first earth house?

When I was a student at architecture school in 1971 I designed a house for a potter named Yvonne Rust who wanted a house made of clay. We didn't know how to do it so I basically got an old book out of the library. Yvonne had met Pip Alley at Canterbury University. He'd made a few houses in the 1950s from earth stabilised with cement, so she sent some soil down for him to test and make a mix that we could build with. That house is still there. I popped in the other day and the new owner said, "Not a day goes by that I don't thank you for this beautiful house."

7 Was there a resurgence in interest in earth building in the 1970s?

No. Only four were built in that decade. New Zealand has a long history of earth building dating back to the 19th century. Pompallier House in Russell is the oldest but the technique fell into disuse by the 1930s. A few servicemen coming back from places like Egypt saw it as a way to build for their own families in the 1950s but it faded again. Interest really revived in the 1980s. We ended up forming an Earth Building Association and developing the official set of standards.

8 Have you battled councils your whole career?

I feel like I have. It used to be a lot easier than it is now. It's an attitude thing. There's an irrational need to tick boxes. I cut down a tree in my backyard to use as a beam and they say, "Prove that it's strong enough". Well look at it - it's enormous for the job it's doing. Things do come unstuck when people don't have a good working knowledge of building, structure, materials, moisture. I get called in to review other people's plans and sometimes the council has reason to be concerned - they're unsafe. Rule-making is difficult. I know, I've written rules. There's a need for respect of people and materials. Part of what they're trying to do is shift liability.

9 Did the leaky building saga change the industry for the worse?

Enormously so. The other thing was the removal of apprenticeships. There's almost a whole generation missing. I'm close to retiring and no obvious successor has come along. I'm worried about passing my skills on. To lose that knowledge seems an awful waste. What we desperately need is a school of natural building. I had a young architecture graduate in my office once who did not know that water runs downhill under the influence of gravity. So she was having a bit of trouble designing a roof. The best learning is the practical, hands-on kind. You can watch an expert on YouTube but you need to actually handle the cloth.

10 Have you ever been through a period when you've been down and how did you come back?

The worst time was after I got metastatic melanoma five years ago. I was very depressed for a couple of years. The hardest thing was adjusting to living in a diminished state. I'd been very busy, often working 16-hour days, but now I'm easily fatigued.

11 Are you a religious or spiritual person?

Not in the slightest. I'm an atheist and I don't get into the "woo woo" stuff. If I have any label it's that deep ecology thing where you feel a total connection with living things on Earth.

12 Do you have fears for the future your grandchildren will grow up in?

I think they're in for a very rough time. We baby boomers had the best of it and collectively we've extracted far too much from the earth. Looking back on my life, I'd hoped to have a bit more influence on the built environment than I have had. That's a frustration. I was probably 20 or 30 years too soon. The big question for our natural building conference in March is why natural materials aren't more widespread? That's why we formed the YIMFY or Yes In My Front Yard trust to encourage more people to build stuff that we're proud to see and can engage with and learn from.