The process of incorporating sustainability in a home begins by defining what is important to you.
This can be done by considering the possible impacts of your home and deciding on the sustainability outcomes that reflect your priorities. This involves making personal decisions about the types, scope and time of impact you think are important.
You might want to pay a smaller energy bill, have warm feet during the winter, or ensure the air in your home is free from chemicals. Or you might want a house that increases your independence from the city water supply, one that relies on the sun and the wind for all its heating and cooling needs, or one that generates all the energy it needs to function and will leave the site in a better condition than it was before the building was there.
As well as your priorities, you should consider your level of knowledge in the area and the amount of time, money and effort you can commit to the project. After defining these aspects, you’ll be able to set objectives that are personally relevant and define measurable targets in the areas that matter to you. A lot of people have gone through this process before you, and there are a range of tools and standards available that can make the journey easier.
This series of articles highlights the following tools that are especially relevant to the New Zealand context:
The Living Building Challenge was launched in 2006 and is managed by the International Living Future Institute. This holistic certification scheme claims to be the most rigorous and ambitious building performance standard in the world. At present, there are no certified ‘Living Buildings’ in New Zealand and no residential projects that have received full certification.
- Net Zero Energy certification is also managed by the International Living Future Institute and is mainly focused on the energy performance of buildings. To obtain certification, a building has to demonstrate after a year of operation that it has met all of the owners’ heating, cooling and electricity needs through on-site energy generation. The Zero Energy House in Point Chevalier is currently the only certified project in New Zealand.
- Homestar is a comprehensive rating system for homes developed by the New Zealand Green Building Council (NZGBC) and BRANZ in consultation with a technical advisory group made up of industry experts. It recognises design strategies that improve comfort and the likely impacts homes have on the environment using a star-based score (1 to 10 stars). Over 120 homes have been built in Auckland with a Homestar rating and an additional 480 homes are expected to be built in the near future.
- The Passive House standard was designed to reduce carbon emissions while improving internal comfort and indoor air quality. It provides homeowners with certainty with regard to what they are getting: a healthy, comfortable home which uses little energy to maintain. There are two certified houses in Auckland at present.
- The High Standard of Sustainability (HSS) was developed by Beacon Pathway, an organisation founded by government agencies and industry partners committed to transforming New Zealand’s homes and neighbourhoods to be high-performing, adaptable, resilient and affordable. It aims to ‘define what achieving a high standard of sustainability in a home means – how the home should perform, and what features are necessary to deliver that level of performance’. Beacon focuses on a ‘whole-of-house’ approach to achieve fundamental changes in ordinary New Zealand homes. The Waitakere NOW Home is one of Beacon’s demonstration projects and was designed according to HSS principles.
The table below compares each tool’s structure and the time required for certification. Similar tables are included in the other articles to illustrate how each tool approaches place and context, energy, water, comfort and health, and waste impacts. While these impacts are separated for the purposes of explanation, it is important to remember that sustainability outcomes require integrated and connected approaches.
| Certification
scheme | Approaches and structure | When do I get certification? |
| Building Code | The minimum requirements every new
home needs to comply with.
Addresses basic health and safety
considerations as well as minimum durability and weather tightness
requirements. | A building consent that demonstrates
compliance is required before construction. |
| Living Building
Challenge | A holistic scheme that requires
exceptional performance across the following categories to achieve
certification:
- Place
- Water
- Energy
- Health & happiness
- Materials
- Equity
- Beauty
The tool also requires projects
to fulfil education and communication requirements to inspire others. | Evaluation is carried out after
12 months of continuous operation and ‘Living Building’ certification can
only be achieved if all requirements of the standard are met. |
| Net
Zero Energy | A certification
that verifies that 100% of the building’s energy needs on an annual basis are
supplied by on-site renewable energy. | Monitored
energy generation and use is audited one year following completion. |
| Homestar | A design and build tool
developed specifically for the NZ context. It evaluates design strategies
across the areas shown below, providing a scale that indicates warmth, health
and resource efficiency:
- Energy, health and comfort
- Water
- Waste
- Management
- Materials
- Site
| There are two non-compulsory checkpoints in the
progress of achieving a Homestar Built Rating: Homestar Appraisal and
Homestar Design Rating. Homestar Appraisal is primarily a marketing
opportunity for the developer to confirm intention to achieve a Homestar
Built Rating. Homestar Design Rating is a full assessment of a proposed
dwelling which will expire after two years.
|
| Passive
House | A strict
building performance standard designed to achieve high levels of energy
efficiency, quality and comfort.
To achieve
certification criteria must be met in the following key areas:
- Heating and cooling
- Airtightness
- Energy use
- Indoor temperatures
| Checks are
carried out throughout design and construction. Final certification is issued
after on-site tests have been completed. |
| High Standard of Sustainability (HSS) | A ‘whole-of-house’ approach that sets
benchmarks to help homeowners understand the performance of their homes.
Targets are set in five areas:
- Energy
- Water
- Indoor environment quality
- Waste
- Materials
Aims to influence and change the
performance of ordinary New Zealand homes. | Using the targets set under the HSS benchmarks homeowners can monitor
their own home performance. |