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Tools and resources

Access a range of tools and calculators for a smarter home.

Siting and location

These smart tools will help you when you’re deciding where to build or buy.

Nature Services

Try Landcare Research’s Nature Services online tool to select suitable local native plant species. (Be patient, it takes a little while for the tool to generate the plant list.)

NIWA SolarView

This calculator estimates the solar energy that can be collected by a solar capture device (solar panel) at a given address, panel direction and roof slope.

The program combines an image of the local landscape with irradiance data from the nearest climate station.

NZ Green Building Council Homestar rating tool

Homestar is an independent rating tool that certifies the health, efficiency and sustainability of New Zealand homes. A home is rated on a 1-10 scale: a rating of 1 Homestar means it needs significant work, and 10 Homestar indicates international best practice. Most existing New Zealand homes only achieve a 2-3 Homestar rating. A new home built only to Building Code would achieve 3-4 Homestar.

Homestar awards points across six categories – Health & Comfort, Energy, Water, Waste, Site and Management.

Upspec your Build – Hutt City Council

If you are building a new home watch this Hutt City Council video about smart ways to make your home warmer, more comfortable and energy efficient.

Walk Score

Enter your address in to this simple online tool and receive a commute report comparing bike, bus and car transit. It shows your options for getting around by car, bus, bike, and foot.

Design

Smart design can provide benefits – use these tools to help you.

BRANZ ALF3.2

The ALF (Annual Loss Factor) tool is a free online aid to the thermal design of houses. It is presented in a step-by-step format providing a simple method of calculating the energy performance of conventional New Zealand houses.

It is also a verification method for determining the Building Performance Index (BPI), which can be used to show compliance with the Energy Efficiency Clause H1 of the New Zealand Building Code.

BRANZ Universal Design (cost calculator)

This small online tool estimates the costs of incorporating key universal design features for your particular situation. Both material and labour costs are included in the costings.

Lifetime Homescore

The Lifemark™ Homescore consists of a simple online list of multiple choice questions. It takes a few minutes to complete and will give you some useful feedback about how easy living in this home will be both now and in the future, and how you could improve your score.

Nature Services

Try Landcare Research’s Nature Services online tool to select suitable local native plant species. (Be patient, it takes a little while for the tool to generate the plant list.)

NZ Green Building Council Homestar rating tool

Homestar is an independent rating tool that certifies the health, efficiency and sustainability of New Zealand homes. A home is rated on a 1-10 scale: a rating of 1 Homestar means it needs significant work, and 10 Homestar indicates international best practice. Most existing New Zealand homes only achieve a 2-3 Homestar rating. A new home built only to Building Code would achieve 3-4 Homestar.

Homestar awards points across six categories – Health & Comfort, Energy, Water, Waste, Site and Management.

Upspec your Build – Hutt City Council

If you are building a new home watch this Hutt City Council video about smart ways to make your home warmer, more comfortable and energy efficient.

Heating, cooling and insulation

Use these tools to help make your home comfortable and efficient to run.

BRANZ ALF3.2

The ALF (Annual Loss Factor) tool is a free online aid to the thermal design of houses. It is presented in a step-by-step format providing a simple method of calculating the energy performance of conventional New Zealand houses.

It is also a verification method for determining the Building Performance Index (BPI), which can be used to show compliance with the Energy Efficiency Clause H1 of the New Zealand Building Code.

BRANZ – Up Spec

Up-Spec is a BRANZ tool and provides actual data for a range of performance improvements for new New Zealand homes across three themes: comfortable temperatures, energy efficiency and water management.

Upspec your Build – Hutt City Council

If you are building a new home watch this Hutt City Council video about smart ways to make your home warmer, more comfortable and energy efficient.

Power, lighting and energy saving

Use these tools to help improve your home’s energy efficiency.

BRANZ ALF3.2

The ALF (Annual Loss Factor) tool is a free online aid to the thermal design of houses. It is presented in a step-by-step format providing a simple method of calculating the energy performance of conventional New Zealand houses.

It is also a verification method for determining the Building Performance Index (BPI), which can be used to show compliance with the Energy Efficiency Clause H1 of the New Zealand Building Code.

BRANZ PV Calculator

The BRANZ PV online calculator can be used to determine the average yearly electricity generation capability (ie energy yield) of a photovoltaic (PV) system.

CarboNZero household calculator

Use Landcare Research’s CarboNZero calculator to estimate your household carbon dioxide emissions, and your home’s carbon footprint.

Energywise Appliance Running Cost Calculator

The running cost calculator allows you to find out how the energy rating affects the amount of energy used for a large range of household appliances, and how much each appliance will cost per year to run.

Energywise Efficient Lighting

Use this tool to select your current bulb, find out which energy efficient light bulbs you could replace it with and how much you could save on your power bill each year.

Energywise Solar Calculator

This calculator helps you assess solar power for your house. You’ll be asked for your address and about your electricity usage and power bill. It will take you about 10-15 minutes to work through the questions. At the end you will get a detailed report estimating how much value you would get from solar.

There is also a video to give you more information on solar. You might want to watch this before you start.

Energywise Water Heater Cost Calculator

Whether you are replacing an existing water heating system, building a new home, or just doing some research, this tool will help you compare your options.

You’ll be asked a number of questions about how you use hot water in your home and your power bill and you’ll get a comparison of the upfront costs (purchase and installation), annual running costs, and lifetime costs of different types of hot water systems.

Homestar

Use the Homestar online tool to see how well your home performs and get recommendations on how to improve it, or book a certified assessment.

NIWA SolarView

This calculator estimates the solar energy that can be collected by a solar capture device (solar panel) at a given address, panel direction and roof slope.

The program combines an image of the local landscape with irradiance data from the nearest climate station.

NZ Green Building Council Homestar rating tool

Homestar is an independent rating tool that certifies the health, efficiency and sustainability of New Zealand homes. A home is rated on a 1-10 scale: a rating of 1 Homestar means it needs significant work, and 10 Homestar indicates international best practice. Most existing New Zealand homes only achieve a 2-3 Homestar rating. A new home built only to Building Code would achieve 3-4 Homestar.

Homestar awards points across six categories – Health & Comfort, Energy, Water, Waste, Site and Management.

Water and waste

It’s important to manage your water responsibly – it’s a valuable resource.

BRANZ – Up Spec

Up-Spec is a BRANZ tool and provides actual data for a range of performance improvements for new New Zealand homes across three themes: comfortable temperatures, energy efficiency and water management.

Nature Services

Try Landcare Research’s Nature Services online tool to select suitable local native plant species. (Be patient, it takes a little while for the tool to generate the plant list.)

Air quality, moisture and ventilation

Use these tools to find smart ways to make your home healthier and drier.

Upspec your Build – Hutt City Council

If you are building a new home watch this Hutt City Council video about smart ways to make your home warmer, more comfortable and energy efficient.

Note that this document is published by the Ministry of Business, Innovation and Employment Chief Executive as Guidance under Section 175 of the Building Act 2004. This is a guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case.