Frequently asked questions
Homestar™ helps you improve the performance of your home – making it better. Better to live in, better for the planet and better value in the market. Live better. Make your house a Homestar™ home.
Who should be using Homestar's Online Assessment?
Everyone! This tool is for all New Zealanders who wish to live with higher levels of comfort and health, whilst saving valuable resources. The language, solutions and market for home efficiency and sustainable housing can be complex and confusing. The rating tool provides a pathway for achieving a warmer, drier, healthier home. Once you have entered some details about the house, Homestar will provide you with advice and information on how you can improve comfort, reduce operating costs and make your home better for the environment.
How long will the self assessment take?
Provided you have all of the information at hand, the online assessment can be completed by most people in about 15 – 20 minutes. The better the information that you can provide, the more accurate the assessment will be and the better the advice in the recommendations.
How many stars are there?
The full Homestar scale is based on a 10 star rating system where 10 is the highest score. A 10 star Homestar home would be a world leading design and would need to be self-sufficient in terms of energy and water. When you test your home online you won’t be able to achieve 10 stars. (See ‘Why can’t I get 10 stars?’)
Why can't I get 10 stars?
Some aspects of very high performing homes need to be assessed and verified by a professional before a formal Certified Rating can be awarded (see Certified Assessment). The online test is a streamlined version of the Certified Rating, designed for home owners and occupiers, who don’t have to be building experts, to provide an indicative rating. Therefore, not all of the points are available in the online test.
The highest rating available using the online test will vary depending on house size and location but is generally about 8 – 9.
What do the stars mean?
A lot! Information from all 52 questions is analysed to produce a score (see ‘How are the stars calculated?’).
It’s important to remember that the overall standard of our houses in New Zealand is pretty low. At the moment, most Kiwi homes rate between two and fours stars. The objective of Homestar is to help people start to improve the health, comfort and efficiency of their home.
The diagram below describes some of the typical ratings of New Zealand homes. A new home designed and built to today’s building code will achieve about 4 stars.
How are the stars calculated?
The way you answer the questions about your home creates points that give your home a final score. This score is then translated to a star rating based on three main factors:
- Base score: This is basically the sum of points awarded for each question. When you answer a question in the test, points are calculated based on your answer. Some questions are worth more than others. This is to reflect the relative importance of certain issue to overall sustainability. For example, a lot of points are available for insulation and only a couple of points are available for fruit trees and vegetable gardens.
- House size:The base score is adjusted by an overall factor determined by the size of the house (question 2) and the number of people that could easily live in the house, based on the number of bedrooms (question 3).The size of a house is one of the biggest single contributors to how sustainable that house can be. In general, a very large house with only a couple of bedrooms is not likely to be very sustainable.
- Mandatory Minimums: These are things that a house must have in order to progress up the scale. There are four levels of mandatory minimums and if they haven’t been achieved, your home won’t be able to move up the scale no matter how you answer the other questions. These essential requirements emphasise the importance of key aspects like insulation, controlling dampness and using water efficiently.
- Basic insulation: To achieve 3 stars or above, a minimum level of insulation must be installed in the home. Due to improvements in the building code houses built since the mid-1990s (when floor insulation requirements were increased), should be built above this standard. Houses built before 1978 (when basic insulation became a requirement) will need retrofitted insulation to achieve this.
- Dampness control and good insulation: To achieve 5 stars or above, the house must have good levels of insulation (slightly better than building code) and specific measures to control dampness. This includes features such as extractor fans in the kitchen and bathrooms and installing polythene on the ground under the house to prevent rising damp (for wooden floors).
- Water efficiency: To achieve 6 stars or above, the house must include some water efficiency measures such as dual flush toilets (with a maximum 6/3 litre flush) and showers with a flow rate of less than 9 litres per minute.
- Excellent insulation: To achieve 7 stars or above, the house must have excellent levels of insulation and ‘thermal mass’. This is more applicable to new homes or major renovations. Examples of excellent insulation include, wall cavities that are thicker than the standard 90 mm to allow thicker insulation to be installed, above building code ceiling insulation that covers all the framework and high performance double glazed windows with thermally broken frames. Thermal mass is any heavy, solid material such as brick or concrete that core store heat. Having tiles or exposed concrete adjacent to north facing windows is an excellent way to transform some of the sun’s energy into heat and to slowly release this heat into the room.
Can I receive a half star?
No, Homestar™ does not give any half stars. Ratings are given in whole numbers only.
I’m renting – is Homestar™ for me?
Yes it is. Anyone renting a home can assess that home – and compare it to what else is out there in the market. By knowing how many stars your home is you will get an idea about how warm, comfortable and healthy it is.
I am building a new home, is Homestar for me?
Absolutely! Homestar is an ideal tool to help inform your design and help you work with your builder, especially while you are still in the early stages of your home’s development. The design stage is a great time to look at all the issues raised in Homestar – and by going through the Homestar tool you will get a good idea of what to include in your plans.
Can I do more than one assessment?
Yes you can – and you can save multiple assessments under the ‘saved properties’ section of the website provided you have registered with Homestar and provided your email and password details.