How To Build an Energy-Efficient House

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Paying too much for electricity? Energy-efficient house design means your home needs less power to stay cool in summer and warm in winter. And with energy prices going up, now is the time to build a more sustainable, energy-efficient, better-built home.

The price increase of up to 18 per cent in NSW from July 1, confirmed by the Australian Energy Regulator, is already here. Coming off the back of the 2022 federal election campaign fought on the cost of living and rising inflation, these rate rises could add roughly $120-$250 a year to your residential power bills.

Now, you could wait for the renewable revolution to bring down power prices across the country, or you can ensure your new home is as energy efficient as possible right now.

Discover energy-efficient house designs and how to ensure your home is up to date and ranking high on the sustainability index, and adheres to the National Construction Code.

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The National Construction Code

Australia’s primary set of technical design and construction provisions for buildings is laid out in the National Construction Code (NCC). Based on performance, the NCC “sets the minimum required level for the safety, health, amenity, accessibility and sustainability of certain buildings.”

The energy efficiency of residential buildings is measured on a scale from 1 to 10. While the previous benchmark score was between 5 and 6, a score of 7 is soon being implemented as the required residential energy efficiency in Australia.

Chief Executive Officer of the ABCB, Gary Rake, explained the reason for lifting the performance of building fabric to 7 stars is to make homes more comfortable for occupants throughout the year and “less prone to being too cold in winter or too hot in summer.”

“The improved building shell means less energy will be needed to heat and cool the home.”

Mr Rake believes that “with our current mix of energy sources,” it could mean “an immediate reduction in greenhouse gas production.” Raising the energy performance of residential buildings also “helps reduce cost of living for people living in the home, whether they are owners or tenants.”

He explains that while one home may meet the energy requirements through very efficient appliances, “another might offset the use of less-efficient appliances with more onsite generation of energy.” 

What is energy efficiency?

The NCC defines energy efficiency as “the prudent, or smart, use of energy resulting from regulatory requirements and voluntary choices in comparison to the amount of energy that would otherwise have been consumed.”

Moreover, the NCC acknowledges the desired outcome is to build homes that use “less energy for heating, cooling, ventilation, lighting and other domestic services whilst maintaining expected standards in these areas.”

Energy efficiency refers to critical residential factors–structure and fixtures. A home with better structural thermal performance will require less cooling and heating. The combination of these energy-efficient house features, in tandem with occupant behaviour, contributes to the total amount of energy consumed.

Structure:

  • Building fabric, e.g. walls, floors and roofs
  • External glazing and shading
  • Sealing of the building
  • Effects of air movement

Fixtures:

  • Insulation
  • Sealing of ductwork
  • Central heating water piping
  • Space heating
  • Artificial lighting
  • Heated water supply system
  • Heating and pumping of swimming pools and spas

For a building to be considered energy efficient, it must be capable of efficiently using energy. It should also obtain power from either a low greenhouse gas intensity source, an onsite renewable energy source, or another reclaimed energy process.

Building an Energy-Efficient House in Australia

Australia also relies on the Nationwide House Energy Rating Scheme (NatHERS) to measure a home’s energy efficiency. Based on a star rating out of ten, the higher the rating, the less energy is needed to heat and cool the home to keep it comfortable. NatHERS assesses house plans and building specifications to estimate the amount of heat added or removed to keep that home comfortable.

While a 6-star rating is a minimum standard for designing an energy-efficient house in most states and territories, it only indicates good but not outstanding thermal performance. A Sydney home with a 7-star rating uses an estimated 23 per cent less energy, while an 8-star home uses approximately 44 per cent less. A 0-star rating, however, means the building shell does practically nothing to reduce the discomfort of hot or cold weather.

NatHERS is about reducing your reliance on artificial heating and cooling by constructing buildings with good insulation and passive solar designs to increase thermal performance during winter and summer. For example, a 10-star rated energy-efficient house plan may not even need artificial cooling or heating.

The Building Sustainability Index

In NSW, homes are measured by the BASIX®, the Building Sustainability Index, which ensures homes are designed to use less potable water and be responsible for fewer greenhouse gas emissions by setting energy and water reduction targets for dwellings and units.

“Attaining a BASIX certificate means that a new residential building has passed the Government’s target to reduce water and energy use in your home.”

Sustainability Features

  • Recycled water
  • Rainwater tanks
  • AAA-rated showerheads and taps
  • Native landscaping
  • Heat pump or solar water heaters
  • Gas space heaters
  • Roof eaves/awnings 
  • Wall/ceiling insulation 

The BASIX certification also scores homes based on other factors, including size, location, design, and any features or fixtures outlined above.

For a home to receive a BASIX® certificate, the home design must meet the requirements across three areas:

  1. Water (minimum score of 40)
    • Showerheads and tap fittings with at least a 3A rating
    • Dual Flush Toilets
    • Rainwater Tank
  1. Energy (minimum score of 50)
    • Efficient hot water system
    • Natural heating, cooling, and lighting design features
  1. Thermal Comfort (pass or fail)
    • The home must have adequate thermal performance for winter and summer, appropriate to its climate.

For coastal NSW, the target for a single dwelling is a 40 per cent reduction in potable water consumption and a 50 per cent reduction in greenhouse gas emissions. 

On average, homes built to the current BASIX standard range between 5.5 and 6-star NatHERS. Better Built Homes, for example, has an average BASIX rating of 5 and 6 for all our home designs.

In combination with the NCC, BASIX has prevented 12.3 million tonnes of greenhouse gas emissions in the past 17 years. These updated reforms will save a further 150,000 tonnes of greenhouse gas annually, meaning cheaper energy bills, more comfortable homes and fewer carbon emissions.

Over half a million homes in NSW meet BASIX energy and water saving standards.

What Makes A Home Energy-Efficient

Known as the Passive House, this design standard developed in Germany takes advantage of natural sources of heating and cooling and minimises unwanted heat gain and loss.

Passive Design works with the local climate to maintain a comfortable temperature inside the house by reducing or eliminating the need for additional heating or cooling. 

  • The position and orientation of your home can dramatically impact your heating and cooling requirements. You should take advantage of the sun and the prevailing winds in your location.
  • The materials used to construct your home can absorb and store heat energy. Finding an appropriate balance for your home’s thermal mass is vital to energy-efficient house design.
  • Insulation primarily acts as a barrier to heat flow. However, some insulation can assist with weather and soundproofing.
  • Glazing is like insulation for windows and can significantly impact the amount of heat retained or lost. 
  • Eaves, awnings, shutters, and plantings–shading can maximise thermal comfort by controlling the sunlight a home receives. 
  • Skylights and roof windows are essentially the opposite of shading and are excellent natural light sources that can impact heat gain.
  • Fresh air is an essential ingredient in any home. However, nobody enjoys a chilly draught from unwanted air leaks. Ensure you have appropriate ventilation and airtightness in your home.
  • Condensation can result in rot and mould, which can be dangerous if left unattended.

Energy Efficient Homes Designed in Sydney

There’s a reason we were voted the best home builder in Sydney and NSW three years in a row. Beyond our offering of modern home designs, our long list of luxury home inclusions and our highly trained customer service team, Better Built Homes ensures our homes are as energy efficient as possible with insulation and solar power.

Insulation

Every Better Built Home design receives the optimal amount of insulation for external walls and ceilings (excluding the garage, ceiling over the garage, alfresco, porch and balcony.) We use Fletcher’s Pink Batts R2.0 for exterior walls and R4.0 for ceilings.

Using innovative technology for manufacturing, Pink Batts® are softer to touch compared to traditional glass wool insulation, providing excellent thermal insulation properties, keeping homes cooler in summer and warmer in winter. Australian-made and manufactured from up to 80% recycled content, Pink Batts are backed by a consumer lifetime warranty, making them the superior choice to deliver energy cost savings for your home.

Solar 

There’s no doubt renewable energy sources are the way to go. One solution for generating clean electricity for your own solar-powered home is the Goodwe 2.0kw PV (photovoltaic) system. An ideal choice for better-built homeowners, our customers typically receive 6-8 Panels depending on the size of their house.

Sustainable, Better Built Homes

See for yourself what a sustainable better-built home looks like in person by visiting our display homes in Western Sydney or embarking on a 3D virtual house tour of some of our most popular home designs.

Contact us today to book an appointment with a Better Built Homes New Home Specialist now, or book online to meet in person with a Sales Specialist at one of our Display Homes. Energy-efficient house designs that meet the modern requirements of Sydney living are just a click away!

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