Sustainability Certification
HomeStar Assessment
HomeStar is an independent rating tool that certifies the health, efficiency and sustainability of New Zealand homes.
Having your home certified to HomeStar standard will ensure the following:
better levels of insulation than Building Code requires, so your home is cheaper to heat
moisture-control measures
water-efficiency measures such as dual flush toilets and low-flow showers, to save you money on water and/or hot-water bills.
GreenStar Assessment and Product Selection
GreenStar is a commitment to standards of best practice and leadership for the development of environmental tools for buildings in New Zealand.
These include:
A common language and standard of measurement
Reduction of environmental impact of development
Recognition of environmental leadership
Reduction of environmental impact of development
Creating healthy and productive building spaces
HomeFit Assessment
HomeFit™ is aimed at recognising and upgrading existing homes to be warm, healthy and efficient. This certification is built in compliance with
the Residential Tenancies Act. Alexander & Co will work with you to ensure that your upgrade achieves this certification.
Net Zero Energy
A net zero energy or carbon building is a building that is highly energy efficient and fully powered from on-site and/or off-site renewable energy sources.
A building that is energy efficient, and supplies energy needs from renewable sources (on-site and/or off-site) is a more appropriate target necessary to achieve high building performance and the Paris Agreement levels of global emission reductions.
H1 Compliance Calculations and Energy modelling
Our building science engineers will give you support and perform all relevant calculations and energy modelling necessary for your project to comply with H1 building code standard.

