Field Notes on Sustainability

Homes are meant to be lived in; we all know that. For the best experience of life at home, good design is essential. Anyone who knows Matt and I would be well aware; we love the design stage of every build and everything involved: we make it the central focus of our work. Those who build a new home encounter no shortage of options to choose from in the way of selections, finishes and stylistic touches. Good design goes even deeper than that; however; sound design is also good for the planet. An ever-increasing bevy of environment-friendly products and techniques is causing a shift in the way that architects, designers and builders approach residential construction. As it turns out, choices that benefit the health of our natural surroundings can also impact the atmosphere in our bank accounts in the long term. This short post serves as a primer for those considering the impact of sustainable building practices; if you're keen to learn more, read on!

Before we begin, let's clarify what we mean by 'sustainable.' In this case, sustainable means that the home has been designed and built with ecological and environmental concerns in mind. Decisions in the process emphasise a responsible approach to building and a low-impact, low-consumption approach to living and ongoing upkeep.

There are many considerations to be made when the aim is to keep the quality high and ecological impact low in any building project. Sustainability works its way into nearly every aspect of the home, and this starts right from the beginning. Every build starts with the same thing; land and earth. When it comes to any and every build site, certain choices maximise the potential of the property for becoming host to a sustainable home. Options can include the dimensions of the house, the orientation of the house on the site and the impacts that the house will have on the surrounding area. A typical example is the rotation of the house concerning the Sun; a north-facing home could incur certain benefits over west-facing, or east-facing home site plans that receive either over-exposure or under-exposure to solar light and heat. The Build7 team across New Zealand prides itself on never building the same home twice; yet another way that we can ensure the optimal relationship between each unique house, the materials within it and the ecosystems around it.

When it comes to materials, the breadth of options available requires a level-headed and experienced approach, informed by both the budget and desired outcome. Before digging into the different types of material options, we'll mention how end products are scored in New Zealand. You may have heard of the term "Homestar" or "HomeStar Rating" before. This scoring system is how inspectors evaluate homes for their level of efficiency. Efficiency is an important word when it comes to sustainable practices, and we'll share some insights around what kind of things impact that before this article concludes. A home can score anywhere between one to ten on the Homestar rating system, 1 being the lowest and most inefficient, and ten being the highest and most efficient. When designing and building, if sustainable choices have been made in the process to earn a particular "star" rating, an inspector will assess the home to see how it fairs against a stringent and extensive set of criteria.

Most new homes built to the specs within the New Zealand Building Code will score between 3-4 on the Homestar ladder without too much further consideration given to efficiency. A score of 6 or higher denotes a home is beginning to make positive differences for the environment and the homeowner. A score of 10 is the pinnacle of sustainable achievement and earns the home the title of a "Superhome", having met or surpassed the most detailed and intricate parameters. Only a select few architects in the country are certified to design and appoint a Superhome, which makes them the ultimate in boutique and bespoke design.

So, what do we mean by efficient? Here are some real-world examples.

One of the most significant factors in the efficiency of a home is the nature of the 'thermal envelope'. The thermal envelope describes the level at which a home's insulated areas retain atmospheric conditions within; in other words, how well does the home stay warm in the winter and cool in the summer? A considerable portion of this value has to do with the insulation utilised and how. The elimination of thermal bridges (areas where heat can transfer or leak) from foundation to roof contribute to the warmth of the home and the amount of energy needed to keep it that way. Conversely, the orientation of the house to shade or sunlight can prevent overheating, reducing the need for air-conditioning.

Low-E recessed windows insulate and retain heat and cool more effectively than other types of window, as a thermal pane works to reduce transfer.

High-efficiency heating systems use less natural resources to keep the home comfortable.

Renewable energy technologies such as solar power and water retention systems allow the home to produce and collect energy and consumables.

Water-efficient wet areas and drainage with specific levels of water pressure ensure that water usage remains low.

Energy-efficient appliances and electronics consume less energy and place less demand on the grid, thus reducing the carbon footprint of the home overall.

Gardens that produce food and the use of native flora contribute to ecological stability.

These are just a handful of the many considerations that play into a sustainable approach to building. It all begs the question; how does it affect the cost of a new home? It's no doubt that sustainability comes with a higher price tag, in some cases, much higher. Each situation requires a fresh start, and in many cases, buyers will build a home that meets code while adding some efficient features as they can afford them; a logical approach. At the same time, for those that invest in high-efficiency design and products, the green they spend upfront saves them some green in the long run and keeps the green around them, well, green.

Which option is right for you? Build7 has established connections with some of the best eco-designers in New Zealand, so no matter what your goals are, we can help make your dream a reality. As always, Matt and I are just a call or an email away.