From the Good Earth

Greg Barron and Jin Ling are internationally renowned clay artists based at Glenbervie near Whangarei. Adept at converting raw earth into vessels and sculptural forms of great beauty, it’s no surprise they chose to build their workshop, gallery, and three-bedroom home from the good earth, ‘poured earth’ in fact.

Earth building stronghold

Greg managed the Quarry Arts Centre in Whangarei during the mid-90s when earth building was becoming a popular construction method in New Zealand. Workshops with Henery Mackeson were held at the Quarry, where well-known architect Graeme North maintained strong associations, and the Earth Building Association (EBANZ) was headquartered. This exposure influenced Greg’s ideas around building. The designs for his house and workshop-gallery are simple.

“I needed to be able to build them myself,” said Greg. “Roofs are a source of water ingress and future problems so I chose functional, traditional design concepts. I considered future maintenance and stayed away from steep roof pitches which aren’t easy to reach as you get older.”

Angled for the sun

Both buildings are long and narrow. The house takes advantage of the sun coming in through north-facing windows and doors. In winter the sun reaches the back wall and masonry floor, which is a heat sink.

In summer grape vines growing over the eaves along the front of the house shade the interior, while the shallow depth of the building allows free flow of air. Even the bathroom and toilet are designed for lots of sunlight, keeping the house warm and dry.

Greg constructed both sizeable buildings virtually alone. The workshop-gallery building took a year including time-consuming design amendments. He and Jin Ling moved into the current workshop, living and working in it for five years while running the Glenbervie Pottery gallery incorporated in the building.

The house took almost two years, but beautiful timber detailing everywhere soon explains the time. It cost approximately $120,000 in materials and planning consents.

Local adobe mix

“It’s an earth building,” says Greg, “and what Yvonne Rust told us all to do. It’s made of materials from a pit just around the corner. I think you have to contribute what you can and we’re trying to do that.”

“We used adobe mix from Dixon’s quarry along the road. It’s really brown rock, sometimes called rotten rock. Under a hammer it shatters into smaller rocks. Some of it is softish but it’s not clay. Clay shrinks as it dries, causing tension and cracking. They pull some clay overburden from the top of the quarry down onto the rock and it’s mixed with the digger. A good amount of aggregate content avoids the problem of clay shrinkage.”

Greg used the adobe mix in a 9:1 ratio with cement – a wet mix with moisture content similar to concrete. He dug 300 mm deep footings for the whole house and filled them with concrete to ground level. Then he added another 300 mm concrete before placing the first shutters on top, beginning at a doorway and forming large blocks with the insertion of wedge-shaped dividers.

The dividers were then moved to an alternating set of holes. Spaces left by the dividers were filled with poured earth from the next level up, adding to the strength of the wall, and resulting in a brick-and-mortar appearance.

The mix went off in half an hour to an hour, so as the shutters were moved for the next course and poured earth filling the divider-spaces oozed a bit, the excess was wiped off with a suitably gloved hand and roughly smoothed over.

As the courses built higher, D12 reinforcing rods were welded to the starter below, and continued up until a threaded rod protruded above wall height to allow a timber top plate, and a washer and bolt to be fixed to it.

The floors in the workshop-gallery were made of a ratio of 9:1 poured earth to cement but it was being damaged by traffic, so Greg increased the cement content of the house floors to 7:1.

The roofs of both buildings are covered with terracotta tiles. They’re fired clay, and in harmony with their work and the environment. Greg and Jin Ling like the weight and durability, and the patina that’s developing.

Timber from next door

Most of the timber in both buildings is treated pine, sourced from a neighbouring property, and felled and milled in the paddock. The New Zealand Building Code requires quick-rotting pine to be treated.

Wall detailing at the ceiling is puriri, but sarking, beams, and window and door lintels are pine. Feature tops such as the kitchen bench and extraordinary bathroom vanity are taraire, and some heavier doors are of totara. Native timbers have come from a large mature stand of trees on the property.

Heavy metal ‘straps’ reach up over ridge beams and are bolted either side to massive pine support posts. They are a fixing point for the beams but also bolster the points at which the beam ends are butted together for continued length. Rafters extending beyond the workshop-gallery roofline create a verandah along the front of the building and have been planed and routered. There is attention to detail everywhere in both constructions.

Energy, heat and water

A solar photovoltaic panel system installed a year ago on the workshop roof provides most of their power needs. The couple run a modern electric vehicle and on the days they need to charge it, the sun doesn’t quite cover their use, but most other days they’re feeding back into the grid.

On the house roof a solar hot water system helps keep a 270-litre hot water cylinder cheaply supplied. It’s an off-the-shelf low-pressure system and they’re pleased with its performance. A large wood fire with wetback supplements winter heat and hot water requirements.

Water is supplied from a bore sunk 30 m into basalt rock. A grated trough runs the entire length of the house ensuring any oversupply of rain is directed into the storm-water outlet instead of indoors. The toilet is a standard flush system.

Organic lifestyle

Greg and Jin Ling are conscious of their impact on the environment and live an organic lifestyle. Over the last year they’ve moved towards veganism, primarily because it’s good for the planet, kind to animals, and good for their health. Greg admits he still has the occasional pang for cheese, wine, and sugar.

Jin Ling runs a barely visible – but enormous – food garden. Cleverly placed plantings include 100 fruit trees, and every border is filled with herbs and vegetables. The grounds are dotted with large exquisitely gentle sculptures created by Jin Ling and sizeable pots and sculptural forms Greg has made, but it isn’t until you look more closely that you see food growing everywhere.

Smaller footprint

All the local materials in the house, workshop and gallery, and the solar energy generation surely have contributed to a small environmental footprint. However if they were to build again, Greg says he would go smaller.

“In 2010 three bedrooms made sense, but the world is changing, and we’re different now. Jin Ling and I could live in half the space.”

 

© Theresa Sjoquist

First published in Organic NZ magazine – January/February 2021 Vol. 80 No.1