Designing a new home
A well-designed house can give you all the warmth, comfort, style and convenience you want, yet use a surprisingly small amount of energy.
It needn't cost much more to build a home designed with energy efficiency in mind and you'll get better comfort and lower energy bills for years to come.
An efficient home is a system in which all the components work together. Below are the key components of energy efficient design.
Good designers, architects and builders
A simple house shape to minimise heat loss
Designed to harness the sun's free warmth
Constructed to keep in the heat
Efficient hot water, lighting and appliances
Good designers, architects and builders
Working with designers, architects and builders that understand energy efficiency design principles - particularly designing for the sun - is important.
A good designer will recognise how the different components in a house work together to create a home that's more comfortable, yet cheaper to run. Not all designers, architects and builders are experienced with this, so it pays to shop around and get references.
A sunny, sheltered site
An optimal building site for a warm, efficient home is:
- north-facing
- sunny and sheltered from prevailing winds, with the home on the sunniest part of the section
- free from things like trees, buildings or hills that can shade the home now or in the future, bearing in mind that the sun is lower in winter.
House sized to suit your needs
Think about how much space you use on a day-to-day basis. Designing a house big enough to cope with all your relatives once a year is generous but impractical. Smaller houses are cheaper to build, easier to heat and use a lot less energy.
A simple shape to minimise heat loss
Simple house designs - like compact, square shapes and multi-level homes - have less external surface area through which to lose heat, so they are easier to keep warm. The more complex a home's shape becomes, the more floor, wall and ceiling area it has for heat to disappear through.
Designed to harness the sun's free warmth
The sun's energy is plentiful, it's everywhere, and it's free. On clear winter days the sun sends about 500 Watts of heat through each square metre of unshaded north-facing windows, so it's worth making the most of that free energy.
A good design can harness the sun's free heat to create a comfortable home that needs relatively little extra energy to keep it warm in winter and cool in summer.
A home designed to harness sun's free warmth:
- is positioned to make the most of the sun, with most-used rooms along the north side
- uses thermal mass - like a concrete floor - exposed to northern sun so it soaks up heat during the day and releases it at night
- has windows sized appropriately for the direction they face - they are moderately large on the north-facing side of the house, small on the east and west sides, and even smaller on the south side.
Learn more detail about designing for the sun.
Constructed to keep in the heat
Good design, materials and construction will enable your home to hold the heat in, so it's more comfortable to live in and cheaper to keep warm.
The important factors for holding in the heat are:
- plenty of properly-installed insulation in ceiling, walls and underfloor
- good double glazing with insulated frames
- use 'air locks' at external entrances to your home, to keep cold draughts out. Entryways, laundries and attached garages can all function as air locks
- good building airtightness coupled with provision for controllable ventilation.
Find out more detail about designing a home to keep in the heat.
Good ventilation control
Ventilation helps remove moisture and maintain air quality in a home. It works together with other elements of a home - like insulation and heating - to create a comfortable, dry, healthy living environment. In summer, ventilation is key to keeping your house cool.
The key things to know about ventilation are:
- Most houses can meet Building Code ventilation requirements with adequately sized and located windows that can be opened.
- Room layout and window placement can be designed to enable effective cross-ventilation, which is good for summer cooling - find out more in the manual Design for the sun.
- Most homes shouldn't need a ventilation system to stay well ventilated - simply opening doors and windows regularly does the job.
- Alternatively, well-designed and installed home ventilation systems can also provide good ventilation but performance can vary widely.
- A ventilation system is not an effective home heating solution. University of Otago research shows that the heat available from moving roof space air into your home (as the most common type of ventilation system does) doesn't provide significant heating benefits compared with what you need to properly heat a home in winter. Read the Otago University research report.
Find out more about ventilation and ventilation systems.
Properly sized, effective heating
Good design will cut your home's heating needs so it can be kept warm and comfortable with a smaller heating sytem. It will also be much cheaper and easier to heat.
There are now lots of efficient heat pumps, pellet fires, log burners and flued gas heaters on the market, either as central heating systems or as individual heaters to heat areas of your house as required. Not all are created equal - for example, some heat pumps are twice as efficient as others - so it pays to do your homework.
Find out more about options for home heating and cooling.
Efficient hot water, lighting and appliances
The systems you use in your home can have a big impact on your home's running costs and environmental impacts. Find out more about:
Building and renovating tool
Use our online tool to find out areas where you can make energy efficient choices tailored to your building or renovating project.
More information
- ConsumerBuild website
- Window Association of New Zealand website
- Waitakere City Council website
- Level website - authority on sustainable building
