Financial rewards of Homestar

Big dollar savings.

Newly published research about Homestar finds the scheme has the potential to give huge financial rewards to homeowners. Savings in mortgage interest rates and power bills could total up to $62,800 for a terraced house in Auckland and up to $98,800 for a standalone house in Wellington over the life of the mortgage loan.

The independent economics consultancy Infometrics carried out the research, commissioned by the NZ Green Building Council and sponsored by Cotality. Brad Olsen, Chief Executive and Principal Economist at Infometrics, says that the additional upfront building cost of a Homestar home, around 0.5% to 1.5% of average building costs, can be recovered from lower costs within just two to three years.

The greater energy efficiency of Homestar homes provides future energy savings estimated at up to $1,500 a year by 2050. A bigger saving comes from access to discounted mortgage rates, such as ANZ's Healthy Home Loan package, which amount to an effective 0.25% discount off mortgage rates.

26 May 2025

 

 

Warm homes on cold nights

Curtains are key.

As the nights get colder and people look for help keeping warm, we recommend the free resource The Magic of Curtains. Beacon Pathway, the Home Performance Advisor Training Programme, BRANZ and the Sustainability Trust tested curtain options for warmth. The work was carried out in a test house on the BRANZ site.

The booklet looks at heat loss around the house and points out that in both insulated and uninsulated homes, windows are where a lot of heat escapes. The research found that:

• Any curtain is better than none.
• Long curtains are better than short curtains.
• Tight curtain tracks are better than tracks that allow gaps.
• Curtains with thick lining give the best performance.

26 May 2025

 

 

Plastic waste in construction

New research findings.

A series of new publications on the BRANZ website give a lot more insight into the issue of plastic waste on construction sites. The reports include:

• ER108 Plastic waste in construction Report 1: Auditing 6 sites in Auckland, where 7.2 tonnes of plastic waste from 6 sites was audited and sorted into 46 groups.
• ER109 Plastic waste in construction Report 2: Barriers to waste management, which found that improved education around reducing plastic waste disposal can help construction companies improve their environmental performance.
• ER110 Plastic waste in construction Report 3: Opportunities for plastic waste management in the Lower South Island, which involved trialling on-site plastic waste separation and working with construction sites to record the data on collected plastics.
• ER111 Plastic waste in construction Report 4: Examining the quantity of packaging, offcuts and built-in plastics components on NZ residential construction sites.
• ER112 Plastic waste in construction Report 5: Fixation methods.

26 May 2025

 

 

Ceiling fans save money

Year-round benefits.

Ceiling fans can reduce electricity consumption when it comes to both warming and cooling the air in a house.

In winter fans can more evenly distribute heat in a room and reduce heating costs. Consumer New Zealand tested a room with a 2000W convection heater against a wall and a ceiling fan. The heater operating alone with thermostat set to 18.5°C used 1.7kW of electricity and the top half of the room was much warmer than the bottom half. When the ceiling fan was turned on at its lowest speed in winter mode (spinning the opposite way to summer mode), the temperature was much more even around the room and the heater's power use dropped to 0.7kW - a 58% saving, more than offsetting the operational cost of the fan. Heater running costs dropped from 44¢/hour to 18¢.

In summer fans provide energy savings when used in conjunction with air conditioning. One test in the US found cooling energy savings of 39% thanks to the use of fans. The average power consumption of the ceiling fans was 8 watts. Fans use vastly less energy than air conditioners/heat pumps. A 5kW heat pump may use 1.2 kWh/hour in cooling mode.

Fans are very energy efficient, and brushless DC fans can be over 60% more efficient than AC fans. Some DC models use just 5–20 watts depending on speed, about the same as an LED lamp. These fans typically offer greater control over fan speeds and can be incredibly quiet but are more expensive to buy than AC fans.

26 May 2025