New Zealand’s growing awareness of doing our part for environmental responsibility has resulted in a significant shift towards industry-wide sustainable building practices. As a significant contributor in the resource and waste consumption space, the construction industry is keen to take responsibility by adopting more eco-friendly solutions. Read on to discover exactly what sustainable housing is, why sustainable building methods are so important here in New Zealand and learn some practical advice and resources for builders, homeowners, and developers.

What Is Sustainable Construction?

The key to defining a sustainable building is that it takes into account the materials, waste, and energy consumption not only during the construction process but also over the entire lifespan of the property, including its eventual demolition and disposal. Essentially, sustainable construction is designed to address the continual impact on the environment and the need to fulfil the economic and social requirements of present and future generations.

6 Key Trends Driving Sustainable Building In NZ

1. Sustainable House Design. Whether it’s passive house design or just building to make the most use of the home’s natural environment. New Zealanders are increasingly focusing on energy efficiency in a big way. Things like superior insulation, airtight construction, high-performance windows, optimising for best use of sunlight, and heat recovery and ventilation are coming in at the top of the sustainability list, but it also extends to things like the home placement on the section, design features and house size and how this affects the ongoing use of the building. Sustainable design is all about designing the building to do the work for you!
2. Renewable Energy And Maximum Energy Efficiency. Consumers are no longer satisfied with just the adoption of energy-efficient technologies (LED lighting, high-performance appliances, and smart home systems) they want full accountability across the entire build. This includes where, when and how materials are made and sourced, alternative energy solutions including solar and wind, overall waste reduction and ethical disposal practices, plus the consideration of building orientation to maximise passive solar gain.
3. Greener Materials. Making sure to use ‘greener’ materials for construction and the ongoing operation of the building are integral parts of building sustainability in NZ. This one now extends right across the life cycle of the build process, including considerations around the lifespan of the building and its eventual demise, as well as placing the spotlight on the manufacturing processes of build materials. There is a growing emphasis on using locally sourced, renewable, and recycled materials. The use of timber, particularly sustainably harvested timber from New Zealand forests, is gaining popularity again due to its low embodied carbon footprint. Other sustainable materials, such as recycled steel and hempcrete are also gaining traction, along with low-VOC paints, sustainable flooring, and recycled insulation.
4. Water Conservation. Water contamination and scarcity are a growing concern for many New Zealanders, which is why they have become integral to the sustainable homes movement. Consumers are increasingly investing in rainwater harvesting systems, greywater recycling, and water-efficient fixtures as standard practice when building a new home, especially in drought-prone areas such as Canterbury and the Hawke’s Bay. Landscaping with drought-tolerant native plants has also gained in popularity to aid in water conservation on larger properties.
5. Green Building Certifications. The rise of ‘Green’ building certifications, such as Green Star and Homestar (governed by the New Zealand Green Building Council (NZGBC) has seen a surge in popularity with home buyers looking to have greater certainty around the sustainability of the home they wish to purchase. Green building certifications provide a consistent framework for assessing and verifying the sustainability performance of buildings both here in NZ and across Australasia. These certifications help to ensure that buildings meet high environmental standards and provide a benchmark for continuous improvement.
6. Ongoing Environmental Impact. Taking into consideration the ongoing environmental implications of the building’s existence and operational by-products, this includes things like the amount of water usage, recycling methods and disposal of household waste. But also extends to things like the lifespan of the building and its eventual demolition and disposal – whether parts can be re-purposed, recycled or must be declared as waste and what happens to that waste.

Why Is Sustainable Building Important?

The desire for more sustainable building practices in NZ has largely been driven by the government’s commitment to achieving its climate change goals, but industry experts have also pushed for growing recognition that greener construction materials and methods are necessary to take responsibility for waste generation, resource depletion, and energy consumption within the industry.

Preserving our natural resources and lessening the detrimental impact on the environment are all important for our health and well-being and that of our planet. Sustainable building is all about preserving and using our available resources in smarter, more efficient ways, so we can move into the future with more affordable homes that are warmer, healthier, and cheaper to run creating buildings that are better for the environment and for future generations.

4 Benefits Of Sustainable Building Design

Ensuring the success of future home building in New Zealand is essential for the construction industry and for the people who live in them! We must move forward with more sustainable building practices and products. Not convinced? Here are 4 of the top benefits of building sustainably.

1. Healthier Homes. Sustainable buildings prioritise healthier and more comfortable indoor spaces through improved ventilation, natural lighting, and the use of non-toxic materials. The result is warmer, drier homes with better air quality that are less likely to contribute to health problems, well-insulated homes with good use of natural light and free warmth from the sun are easier to heat and more comfortable year-round, and better access to natural light and green spaces (which can help mental and physical health).
2. Lower Operating Costs. When following the concepts of sustainable building practices, choosing economic heating options and energy and water-efficient appliances makes homes cheaper to operate over their lifespan, saving money and resources. There is even the possibility of longer-term property value increases as sustainably certified buildings are increasingly in demand among homeowners.
3. Resource Conservation. Practices like rainwater harvesting, greywater recycling, and the use of recycled materials help conserve precious resources. Efficient use of key resources such as water, materials, land, and energy means the total environmental impact of the building is minimised, preserving resources and the planet for future generations.
4. Reduced Environmental Impact. A lower carbon footprint means a reduction in greenhouse gas emissions through greater energy efficiency, renewables, and the selection of low-impact materials, as well as doing your bit for climate change!

Sustainable Building Materials

Regardless of how well a product contributes to your home’s efficiency, every raw material used in the construction process has its own environmental cost. Even materials drawn from nature, like wood are transported, processed and manufactured into products suitable for use in building your new home.

While it is impossible to build without any cost to the environment or energy use, you can minimise the impact in many ways. This can include looking at recycled or renewable materials or using materials that will help in the overall energy consumption in the long run.

What Materials Are Used In Sustainable Building In NZ?

In the construction industry in NZ, environmentally friendly materials (also referred to as ‘green’ building materials) are those with relatively low environmental impact during their production, transportation and ongoing maintenance. These materials need to be natural, durable, reusable and/or recyclable, and preferably be composed (at least in part) of recycled materials, while also having been sourced from local resources in New Zealand. Some examples of sustainable building materials in NZ are:

• Brick (or recycled)
• Timber (sustainably sourced, reclaimed or recycled)
• Recycled steel (or re-purposed steel)
• Wool (recycled or from NZ sheep in particular)
• Bamboo (if sourced in NZ)
• Straw Bale (if sourced in NZ)
• Sawdust (collected as a by-product from the creation of other products)
• Concrete (recycled or concrete-type products like Timbercrete, Hempcrete)
• Soil (Rammed Earth style building products)

NZ Sustainable Home Ratings

The demand for greener buildings, the drive for sustainable construction in New Zealand, has brought about a couple of industry-regulated rating systems as a way of measuring the sustainable features and environmental impact over the life-cycle of a building. These are the ‘Green Star’ and ‘Homestar’ rating systems created by the New Zealand Green Building Council (NZGBC).

1. Green Star Rating (Commercial Buildings)

Designed to be used as a tool in the design, construction and operation of sustainable commercial building projects, the Green Star Rating addresses nine broad categories and gives an overall rating from 1 to 6, with 6 being the best. The categories covered under the Green Star Rating system are:

• Water
• Energy
• Materials
• Transport
• Indoor Environmental Quality (IEQ)
• Management
• Emissions
• Land use and ecology
• Innovation

2. The Homestar Rating (Residential Homes)

This system is similar to the Green Star Rating but was designed specifically for New Zealand and takes into account both the design and build stages of the new home construction process. The ratings given are from 6 to 10, with a 6 indicating the home is better than the average NZ home and current building codes and 10 indicating the home is at the top of the scale. The categories covered under the Homestar Rating system are:

• Energy Usage
• Moisture Control
• Water Usage
• Waste
• Vegetation
• Glazing
• Embodied Carbon
• Ventilation
• Seasonal Comfort

5 Easy Steps To Make Your House More Sustainable

There is no better time to incorporate sustainability into your project than when building a new home. Careful design and choice of materials will future-proof your build, providing a durable long lasting healthy home. Here are our top 5 easy-to-implement tips on making your new build more sustainable.

1. Insulation Insulation Insulation! Ensuring adequate insulation is sourced, and sometimes adding additional insulation to places like attached garages or using extra in ceilings is a good idea. The more insulation you use in the walls, floor and ceiling the more efficiently it will retain heat. Consider using alternative products like wool-based insulation products that are made from recycled NZ sheep’s wool.
2. Make The Most Of The Sun. From the purchase of your section and throughout the design phase, this one should be at the top of your list, in fact, if you had to choose one thing for sustainable building, then this is it! Making the best use of natural light and free warmth from the sun is the very best way to reduce ongoing energy usage in your home and make it warmer and healthier – working towards more passive home heating.
3. Choose Non-Toxic And Sustainable Materials. Look out for the Environmental Choice tick of approval (ECNZ) in everything from paint and building materials through to carpets and cement. Choosing sustainable building materials helps to lower the impact of your new build and allows for greater recycling and less waste on demolition.
4. Source Materials Locally Where Possible. This is a big one in New Zealand as we have a habit of importing a lot of our heavily manufactured products. Sourcing locally reduces the environmental impact, particularly around transportation and storage, which is better for the environment and better for NZ!
5. Choose Energy Efficient Appliances. Selecting appliances with high energy-efficiency ratings will save on energy and money over the lifetime of the product. This can also include thinking about renewable options such as off-grid sewerage systems and rainwater collection systems.

Useful Resources For Sustainable Building In NZ

• New Zealand Green Building Council (NZGBC). Provides resources, education, and advocacy for sustainable building practices. The NZGBC Administers the Green Star and Homestar certifications.
• Building Performance (MBIE). Ministry of Business, Innovation and Employment (MBIE) provided information on building regulations and standards, including energy efficiency requirements.
• Building Research Association of New Zealand (BRANZ). BRANZ Conducts research and provides information on building science and technology, including sustainable building practices.
• Energy Efficiency Conservation Authority (EECA). The EECA provides information and resources on energy efficiency and renewable energy in NZ.

Planning on building or renovating and want to build more sustainably but need ways to save on costs? The Combined Building Supplies Co-Op offers members discounts and rebates across all major suppliers in NZ – help create a better future with sustainable building practices today!