A Sustainable Lifestyle & Eco Building

Eco building is environmentally sustainable construction that minimizes environmental impact and creates healthier habitats. Eco building is catching on in NZ with 15% of houses having some eco aspect. It is a rapidly-evolving and exciting field of architectural design which carries some initial costs but saves in the long run.

Building a house is the single most damaging act against the environment that people do. Therefore it makes a lot of sense to reduce the initial and continuing contributions to global warming. The average house build will cause 80 tonnes of C02 emissions and produce another tonne per year. See house calculator.

The cost of building a naturally-heating and cooling house could be more expensive initially but will save 1/3 of your electricity bill. For an average NZ household that’s $700 per year / over the 50 year minimum life of the building, totaling $35,000; more if the cost of electricity rises. Investing in solar water heating ($6-9K) would cut the electricity bill by another third. Investing $10-15k for solar panels, the bills or battery maintenance would only cost 10 -20% of a conventional house. 12 or so years payback – this reduces to approximately 18 months if you have an electric car and are able to replace fuel costs with the electricity you produce. The economics of solar work out well.

Smart Eco design 
Making the most of natural resources – sun, air & water.

Passive solar heating
Orientated towards the sun.
Thermal mass heated by winter sun keeps the house warm and cool in summer.
Solar panels generate electricity into batteries or grid-tied.
Solar hot water panels.

Maximize natural light
Strategically placed windows over work spaces and walkways.

Good ventilation
Make the most of prevailing summer winds and the rising of hot air to draw in the cooler external ground air, creating natural AC.

Water efficiency
Harvest rain water with low-flow faucets. Recycle grey water.

Sustainable alternatives
Choose materials that use less energy to produce and use and give off less or no hazardous toxic chemicals.

Get the same function with less materials / components.

Thermal envelope around the house
Lots of high quality insulation.
Well-wrapped and sealed house.
Double-glazing and thermal curtains.
Careful construction with no thermal bridges.

3 Rs: Reduce Recycle and Reuse
Reduce – Smaller is less harmful.
Reuse – Choose materials that can be reused. Cradle-to-Cradle thinking.
Recycle – Timber & joinery – collect and store the materials.

Eco-building is a great sustainable start to helping out the planet. We’re at the stage where sustainable isn’t enough. It’s just a slower way to die. We need to regenerate our eco-systems to survive and thrive. Houses can give more than they take. See the Living Building challenge. Do your own carbon off-set by planting lots of trees to balance the eco deficit. Produce more power than you need and sell it to a daylight user – a nearby shop or office. Better still leave the car in the garage and cycle – Find a better way to go and show others the path.

Eco building suits all budgets – from using recyled materials to remote controlled smart houses with cladding and panels that power the house and the car.

There are a number of different eco ratings that can be applied to houses. They provide a useful benchmark if you’re buying a house from a construction company. We are currently investigating using the Homestar rating system.

Homestar is a comprehensive, independent national rating tool that measures the health, warmth and efficiency of New Zealand houses. A home is rated on a scale from 6 to 10.

A 6 homestar rating or higher provides assurance that a house will be better quality – warmer, drier, healthier and cost less to run – than a typical new house built to building code. A 10 homestar rating means you’ve built a world leading house

Homestar assesses a house, apartment or multi unit development against several categories including energy, health and comfort; water waste and materials. There are two stages to a homestar rating:

1) Design – this rating assesses the full and final plans.

2) Built – this rating occurs after a homes is constructed. It certifies that the features in the Design rating have been fully implemented.

A well-designed and ventilated house creates a healthier and longer lasting home by reducing condensation, leading to less mould and rot. Regular construction has lots of nasty components in the materials. Familiarise yourself with the information about live VOC’s – which pollute the airways by releasing them in to the atmosphere – best avoided.

Choosing green materials requires considerable time and costs – on average 20% more. Cradle to Cradle perspective gives the best account of the material – what it is made of, where it is from, how much energy to make and transport, how it functions in the house and whether or not it can be reused afterwards.

The ideal material is totally natural, has low-embodied energy, is easy to work with and lasts a long time. Clay from the site for your core structure is about as green as it gets. Take advantage of your local resources, put pressure on your builders’ merchants to supply healthy alternatives and cut down on the packaging & waste. There are red lists and green lists which make it easier to know what to avoid and good alternatives.

Cement lasts a long time but is responsible for 11% of C02 emissions. Hard to avoid when building a house.

Wood is really sustainable in NZ. The treatment for rot can be very toxic, avoid CCA. There are better treatments and species which are naturally rot-resistant.

Wool has high UV protection and is a renewable, fire retardant, biodegradable, durable, elastic and natural insulator.

Enviroboard can be made from straw. Construction panels, like enviroboard, built from agricultural wastes, have been around for hundreds of years, especially in Central and Eastern Europe where pressed leaves and straw were used as insulation and even structural material.

Strawblocks are strawbales that have been recompressed to the density of wood blocks. This makes them more efficient to transport and also add strength and solidity to load-bearing walls. 

Adobe / Clay – At least half of the world’s population live or work in a building made with clay as an essential part of its load-bearing structure. Many natural building techniques use clay as a primary material. Adobe, cob, cordwood, and rammed earth structures all use clay as well as building elements such as floors and renders. It has great thermal properties.

These web pages give some guidance and outlines to eco building and links to the wealth of online information.

The Red List of materials to avoid https://living-future.org/declare/declare-about/red-list/

The Green List of good alternatives https://living-future.org/declare/

Zero energy house – Leading the field in sustainable house construction in NZ

Living Building Tuhoe

Design Information

Free eco-building advice

Design assistance

Dream Green Homes – a source for almost free green building plans

The new brochure “Everything you always wanted to know about Passive Houses in New Zealand” from PHINZ

Porotherm Clay Construction Blocks

Earth Bay Building in Raglan

Local / National Professionals and Resources

Terra Firma Professional Rammed-earth buiders.

Phone: +64 9 963 5942

Mobile: +64 21 843 669

Clint Goldie



Tim Gittos (Arcitect for site and Shaun / Carmels Home) http://www.spacecraftarchitects.co.nz/

Local eco architect Duncan Firth

The Quarry Arts Centre in Whangarei is a national center for Earth Building. Lots of earth buildings, knowledge and courses. Birthplace of EBANZ Earth building Australia New Zealand http://quarryarts.org/

This report was kindly compiled by Peter Grant, Project Manager and Design Consultant of the Whangarei-based company “Eco Projects” http://ecoprojects.nz/  

November 2017

Ahi Wai - Eco Neighbourhood

Shaun Davison and Carmel Henry
Whangarei 0112
09 4372120