Adapted to specific New Zealand conditions, Homestar is a comprehensive rating tool that can be used to measure the performance and environmental impact of any residential dwelling, from stand-alone homes to large multi-unit residences. Homestar assess these structures during the design process and after completion of new and existing homes against several categories which include building materials used and the resulting health, comfort and energy efficiency.

Materials

Utilising building materials that are safer for people living in the home and that have lower environmental impacts over their lifetime is another important consideration when creating a healthier, quality home. The GreenStuf range of thermal and acoustic insulation products are made from polyester material and have been independently assessed as being non-toxic and environmentally friendly. Global GreenTag has certified GreenStuf range with Product Health Declaration certification and the product achieved a Platinum status. This indicates that they are 100% safe for human health with low to no associated risk during handling, product use and disposal. This certification, in addition to its Declare certification, makes Greenstuf a market leader. The GreenStuf range also has a lower environmental impact. Manufactured to best practices under the ISO 9001 and ISO 14001 accredited Quality and Environmental Management Systems, GreenStuf is made with a minimum of 45% recycled PET plastic and is recyclable at the end of its life.

Health, Comfort and Energy Efficiency

Achieving a healthy and comfortable indoor environment whilst also reducing energy consumption are important factors in creating a modern sustainable home. According to Auckland Council eco design adviser Adrian Feasey, the average home consumes 30 to 35 per cent of its energy in space heating (Collins, 2015). Insulation is a key factor in managing the energy efficiency of the building envelope. A high-rating Homestar home will have a well-designed thermal envelope that fits a higher level of insulation than required in the New Zealand Building Code. The outcome is a home that is warm in winter and cool in summer while achieving a high level of energy efficiency. This is important when considering that 91% of home buyers place value on natural warmth and 72% value energy efficiency (New Zealand Green Building Council, n.d.) Insulation also helps to reduce dampness and mould, creating a drier and healthier home.

Zero Energy House

A great example of a better built home with energy efficiency and sustainability at its core is the Zero Energy house in Point Chevalier, Auckland. Two major design goals for the build were to reduce energy consumption and to generate energy via solar panels. Balancing out energy consumption and generation helped the designers achieve a zero energy home.

The timber wall framing was purposely designed with extra depth and nogs removed and replaced with supporting battens, allowing for a double layer of GreenStuf insulation to run the full height between studs, reducing thermal bridging and increasing overall thermal performance. A clever combination of GreenStuf R2.0 Wall Pads and R1.0 Masonry Wall Blanket in the walls, with GreenStuf R3.2 and R2.5 Thermal Roll Form used in the ceiling as well as acoustic Sound Solution throughout the residential dwelling. The result of incorporating a higher level of insulation created a better thermal envelope, ultimately reducing energy consumption.