Building an energy efficient High Performance Home in New Zealand
- Airtightness: Enhanced airtightness minimizes energy waste, maintains consistent indoor temperatures, and prevents moisture-related issues.
- Ventilation: Mechanical ventilation with heat recovery ensures fresh, filtered air while managing pollutants and humidity.
Together, these upgrades optimise energy use, promote health, and enhance the home’s durability.
Transforming a standard house into a High-Performance Home with the AeroBarrier system adds very little cost to a new build or a renovation and provides immediate ongoing cost savings.
Key benefits of High Performance Homes
Exceptional energy efficiency – save money
- Lower heating and cooling costs, with up to 90% more efficiency in new homes and even greater savings in existing homes. (refer or link to BRANZ Chart below)
- Consistent indoor temperatures
Comfort – warm in winter, cool in summer
- Eliminates cold spots and draughts, creating a consistently comfortable environment.
- Reduces overheating in summer while maintaining warmth in winter for year-round comfort.
- Minimizes noise from outside, providing a quieter indoor space.
Better air quality – healthy family
- Airtight walls, in combination with active ventilation, significantly reduces the likelihood of moisture and mould.
- Air with fewer allergens improves respiratory health.
- Filters remove dust, pollen, and VOCs, while fresh air circulation eliminates odours, enhancing wellbeing.
Greater building durability – better resale value
- High-Performance Homes have higher resale value.1
- Prevents condensation in the walls and ceiling, protecting the structure and finishes.
Increasing airtightness to save energy
In a controlled study, BRANZ (The Building Research Association of New Zealand) scientists improved the airtightness of a house and measured its impact on energy use. Their findings showed that reducing airtightness from 9 ACH50 to 1 ACH50, combined with high-efficiency heat recovery ventilation, increased energy efficiency by up to 90%.
Many new homes in New Zealand range from 8 ACH50 to 10 ACH50, while older homes often exceed 20 ACH50. Based on BRANZ data, this highlights a significant opportunity to enhance energy efficiency, comfort, and durability in New Zealand homes.
According to Jason Quinn (Sustainable Engineering Ltd), many people are spending up to $3,000 on heating and cooling so these energy savings will make a substantial difference to annual costs.
How airtightness is measured
Airtightness is measured using the global standard of ACH50. Tests quantify air leakage by pressurizing or depressurizing the home with a blower door fan. A lower ACH50 score indicates higher efficiency, reduced energy loss, and better protection against drafts and moisture.
While airtightness testing is mandatory in North America, the UK, and much of
Europe due to its importance in home performance, it remains optional in New
Zealand. You have to request it from your builder or architect.
Airtightness certificates
AeroBarrier Certificate
The AeroBarrier certificate is a masked building envelope airtightness test, conducted as part of the AeroBarrier air sealing process during construction. The certificate records the initial and final air changes per hour and the energy savings achieved by improving airtightness. This certificate identifies the improvement in ACH and level of airtightness achieved. It can also serve as a component of the Aero High Performance Home CertificateBlower Door Certificate
The blower door certificate is an in-use building envelope airtightness test, conducted after construction is complete. The certificate records the final ACH50 is recorded for the home as it will be in use. This certificate provides validation of airtightness performance of the house ‘in use,’ ensuring the building meets industry specifications for energy efficiency and quality.Why these certificates matter
These certifications provide transparency and assurance in building performance, helping homeowners, builders, and industry professionals ensure homes are built to high standards of airtightness, energy efficiency, and durability. High Performance Home frameworks require airtightness certificates for their certification process.
Aero Home Performance Rating
Building technologists agree on the key drivers for high-performance homes, as summarised in the table below.
| | Lowers performance rating | | | | Increases performance rating |
|---|---|---|---|---|---|
| Airtightness level | Over 10 ACH50 | 5 -10 ACH50 | 5 - 3 ACH50 | 3 - 1.5 ACH50 | Under 1.5 ACH50 |
| Ventilation level | Windows and extractor fans | Continuous mechanical ventilation | Balanced mechanical ventilation | Balanced mechanical ventilation with heat recovery | |
| Insulation level | No insulation | Ceiling and underfloor insulation | Wall, ceiling, floor insulation | ||
| Glazing level | Single pane | Double glazing | Double glazing with thermal break | Tripple glazing or better | |
Using the principles in this chart, Aero can assess a home and issue a performance certificate based on its overall efficiency.
The system balances different factors, allowing strong performance in one area to offset lower ratings in another. For example, a renovated home with high airtightness, heat recovery ventilation, and double glazing—even without full wall insulation—could still qualify as a High-Performance Home.
Aero High Performance Home Certificate
- Advanced High Performance Home: Surpasses building codes with advanced systems for energy efficiency, comfort, air quality, and durability, meeting top performance standards.
- High Performance Home: Exceeds code with upgraded systems and materials, providing better efficiency, comfort, and durability.
- Code-minimum home: Meets basic building codes but falls below global standards for energy efficiency and air quality.
- Below code standards: Lacks modern insulation, ventilation, and efficiency, typical of many older homes.
- Substandard performance: Poor energy efficiency, air quality, and durability, often needing major upgrades to meet basic standards.
How do you assess the quality of a house?
Every new home should meet code minimum standards, but many existing homes fall short.
- New Homes – Builders can upgrade standard new builds to High-Performance homes with better airtightness and ventilation.
- Renovations – Aero helps renovation builders improve older homes to meet or even exceed modern standards.
The Aero High-Performance Home Certificate allows buyers to identify a higher performing home and helps builders showcase their superior craftsmanship.
High Performance Home frameworks in New Zealand
Aero makes it simple and cost effective to achieve all levels of airtightness. (link to
Homestar page)
Passive House
Passive House New Zealand (PHNZ) promotes the Passive House standard, a globally recognized approach to ultra-energy-efficient buildings. It emphasizes superior thermal performance and airtight construction for comfortable, healthy, and energy-efficient homes.
A key requirement is achieving an airtightness of no more than 0.6 air changes per hour (ACH50) – far stricter than New Zealand’s building code – to minimize heat loss, control ventilation, and prevent moisture-related issues.
SIPS High Performance Home
A SIPS high-performance home is an energy-efficient dwelling built with Structural Insulated Panels (SIPS), offering superior insulation, strength, and airtightness.
These homes minimize thermal bridging and air leaks, ensuring consistent indoor temperatures and reduced energy use.
Airtightness is key to preventing energy loss, moisture issues, and poor air quality. When paired with proper ventilation, the airtight design enhances comfort, lowers utility costs, and promotes healthier, more sustainable living.
Superhome Movement
The Superhome Movement is a New Zealand initiative promoting energy-efficient, sustainable, and healthy homes that go beyond building code standards. It emphasizes better insulation, ventilation, and airtightness for comfortable, cost-effective, and eco-friendly living.
Airtightness plays a crucial role by reducing energy loss, preventing moisture issues, and improving indoor air quality. This enhances energy performance, increases durability, and creates healthier living conditions by preventing mould and dampness.
Net-Zero Energy Homes
Net-Zero Energy Homes, which produce as much energy as they consume annually through efficiency and renewable energy systems like solar panels, are gaining global popularity.
Energy modellers, who specify the solar panels required, can use increased airtightness to reduce the number of panels required. This enhances investment value with quicker payback, lasting savings, and improved sustainability and affordability, especially when paired with high-performance homes.
| Homestar rating | 7 Homestar and below | 8 Homestar | 9 Homestar | 10 Homestar |
|---|---|---|---|---|
| Airtightness requirement ACH50 | 5.0 | 3.0 | 2.0 | 1.0 |
How much does it cost to install AeroBarrier?
There are several options for lifting houses built at minimum building code standards to High Performance Home standards. The Aero system is by far the most cost effective method.
A typical 190 m² house from a large building company, costs around $600,000 to $700,000 (excluding land).
Air sealing a house with Aero only adds around $5,000 to the overall cost of a new home. Ventilation systems range from $3,000 for acceptable systems up to $15,000 for Mechanical Ventilation with Heat Recovery (MVHR). A typical cost for a mid sized new home is around $13,000.
In comparison, SIPs homes are typically in the mid-cost range, while architecturally designed Passive Homes fall in the high-cost bracket.
Immediate cost savings
A High-Performance Home isn’t just about energy savings—it’s a smart upgrade with real benefits.
Using BRANZ data, typical mortgage rates, and estimated costs, here are examples of potential savings from installing airtight ventilation systems. The system cost estimate is based on a typical medium-sized new home.
Jason Quinn, a leading energy modeller in NZ, estimates many households spend around $3,000 annually on heating and cooling. Even if your costs are as low as $1,000 per year, improving airtightness and adding heat recovery ventilation can deliver immediate savings.
A High-Performance Home offers more than just energy savings—it creates a healthier, more comfortable, and durable living environment.
- Moisture control – Prevents mould and mildew in wall cavities.
- Manage overheating – Helps reduce the problems of overheating
- Durability – Reduces timber rot by keeping damp areas dry.
- Healthy air – Filters out pollen, pollutants, and allergens.
- Year-round comfort – Stays warm in winter and cool in summer.
These benefits not only improve quality of life but the investment in home performance upgrades actually save you money.
| Immediate cost savings | | | |
|---|---|---|---|
| System cost AeroBarrier plus heat recovery ventilation | $13,000 | $13,000 | $13,000 |
| Annual mortgage payment cost Interest rate Annual system cost | 6.00% $780 | 6.00% $780 | 6.00% $780 |
| Current annual heating and cooling cost assumptions Assumption of current level of spend Annual spend | Higher $3,000 | Moderate $2,000 | Low $1,000 |
| Energy saving from airtightness and ventilation Energy saving % Annual energy saving $ | 90% $2,700 | 90% $1,800 | 90% $900 |
| Net annual cost saving Annual energy saving Annual system cost (mortgage) Net annual saving after mortgage cost | $2,700 $780 $1,920 | $1,800 $780 $1,020 | $900 $780 $120 |
Book your High Performance Home consultation
At Aero, we’re committed to helping you create better, more efficient spaces. Contact us today to schedule High Performance Home consultation to learn more about AeroBarrier, or take the next step toward a healthier, more energy-efficient building.
