There’s more to sustainable construction than chucking some solar panels on the roof and double glazing your windows. Eco-conscious building should start well before the laying of the foundations with two important questions: where can we place our new build in order to inflict the least amount of damage, and how small can we make our house without compromising on comfort?

It goes without saying that you’re not doing the planet any favours if you choose to cut down established trees in order to put your house in the ‘right spot.’ The amount of shade and sunlight that your house will receive are also things to take into consideration, as is the quality of the land you are building on. If the ground is so unstable that your local council decrees that you need to use a reinforced concrete raft or drive poles into the ground in order to build, then you will be on the back foot in regards to both budget and sustainability before you’ve even begun.

The drive to ‘keep up with the Jones’s’ that began with the flashy consumerism of the 80s is fast becoming unsustainable, with even the most modest of new builds boasting a minimum of two bathrooms and three bedrooms with an office. Covenants on subdivisions have only exacerbated the problem, with many developers stipulating a minimum size for new builds, ostensibly to ensure that the construction is of a high standard.

It can actually be surprisingly difficult to construct a small home in New Zealand in 2024 (not to be confused with a tiny home, which is a whole different ball game), with many banks reluctant to lend to clients who want to build a simple two bedroom/one bathroom home, citing  fears that such a building will be difficult to sell down the track.

At the end of the day the smaller the house the smaller the footprint, as small houses use fewer materials and are more energy efficient than their larger counterparts. Hopefully, the trend for bigger and bigger houses will eventually start to decline as the housing shortage worsens and older New Zealanders start to question why their forty-year-old children are still living at home!

The third major consideration when looking to build sustainably is your building materials. Truly eco-friendly construction will involve minimising the use of concrete. This ubiquitous substance, which forms the backbone of almost every piece of infrastructure on the planet, is such an integral part of human industry that it’s easy to forget how harmful it is to the environment. It has been said that concrete production is responsible for a tenth of the world’s industrial water usage, and its lack of porosity and incredible ability to absorb the sun’s rays has contributed significantly to the catastrophic global flooding that we now experience on a regular basis. The fact is rainwater needs somewhere to go!

So, while it’s hard to avoid using concrete in your foundations, it pays to think hard about how much concrete you need around the outside of your home. Absorbent materials such as sand, soil, and gravel allow rainwater to get to where it needs to be, instead of running off your driveway and into the nearest drain.

There are a number of sustainable materials that you can use to build the exterior of your eco-friendly home, among them timber (check its green credentials first), rammed earth, and natural stone. This includes organic limestone, a robust and durable material with incredible insulating properties that can be used both inside and out.

The materials that you use inside your home are no less important. Plasterboard, or GIB as it is more commonly known is surprisingly sustainable, as are porcelain and wood. When deciding  on which materials to use in your kitchen and bathroom it’s important to be aware that Formica, concrete, and composite stone benchtops all have a substantial carbon footprint.

The list of ways in which you can reduce the negative impact of building a new home is limited only by your imagination, but here are the basics:

  • High quality ventilation
  • A greater standard of insulation than is required by law in NZ
  • Utilising natural lighting with windows and skylights
  • Decorating with low-emission paint
  • Installing greywater recycling
  • Going solar (not just your hot water cylinder people!)
  • Double glazing
  • Low flow water pressure in your shower
  • Cover those windows!
  • Choosing sustainable materials such as wood and stone
  • Recycling where possible
  • Opting for woollen carpets over synthetic

It is always going to be cheaper to incorporate green technology into your new build from the beginning rather than fitting it retrospectively, so you need to decide which of the suggestions on the above list will have the biggest effect on your carbon footprint and factor the cost into your budget from the outset.

If building with stone sounds like it might be something you’d be interested in, Oamaru Stone is 100% natural and organic, and hewn directly from the earth to be delivered to your door. Our stone is almost zero waste, with any leftovers from the cutting process heading next door to our sister company Parkside Lime, to be turned into agricultural lime and returned to the earth. It’s hard to get greener than that. Give the team at Oamaru Stone a call and get started on your sustainable building journey today.