“Single Phase vs 3 Phase Power: Making the Right Choice for Your New Custom Home”

Single Phase vs 3 Phase Power: Making the Right Choice for Your New Custom Home

When you’re planning a new custom home, most of the exciting decisions are easy to see.

You’re thinking about your kitchen layout, that perfect open-plan living space, where the kids’ rooms will go, and of course, the look of the home from the street – including a fresh, modern white Colorbond roof that keeps everything cool and bright.

Behind all of that, there’s a quieter decision that doesn’t get as much attention, but has a big impact on how your home actually lives and feels day to day:

Will your new home run on single phase power or 3 phase power?

For years, most existing homes have simply used single phase by default. But with the way we now live in Brisbane and across South East Queensland – bigger air-conditioning systems, more electrical appliances, solar, batteries and electric vehicles – 3 phase power is becoming more common, and often the smarter long-term choice.

This guide is here to walk you through the difference in plain English, explain what’s changed in recent years, and help you understand why more new custom homes are moving to 3 phase power.

We’ll also show you how Homes by Markon considers this early in the design of your new custom home so your power supply suits the way you live now – and the way you’ll live in the future.

What Is Single Phase Power vs 3 Phase Power?

Let’s start with the basics, without the technical jargon.

Single phase power – the traditional standard

Single phase power is what most people think of as a “normal” home power supply. It’s been the standard in many suburban homes across Brisbane and SEQ for decades.

A simple way to picture it is this:

Imagine a single lane road bringing electricity into your home.
All your appliances – lights, air-conditioning, oven, fridge, washing machine – share that same lane.
As long as the total traffic on that lane doesn’t get too heavy, everything runs smoothly.

For smaller homes with modest electrical demand, single phase power can work perfectly well. It’s familiar, it’s simple, and it has been the default choice for a long time.

3 phase power – three lanes instead of one

3 phase power, on the other hand, is like having a three-lane highway feeding your home.

You still get the same 230–240 volts at your power points.
But behind the scenes, there are three separate phases of power coming into the property.
This gives your home more overall capacity and a smoother way to share heavier electrical loads.

Traditionally, 3 phase power has been used for commercial buildings, workshops and very large loads. These days, more and more new custom homes – especially larger homes and homes with ducted air-conditioning, solar, batteries and EV provisions – are moving to 3 phase because it simply handles modern electrical demands better.

The key point:
You don’t need to become an electrician to make the right choice. You just need a basic understanding of what each option offers, and a builder who designs your home with the right power supply from the start.

Why This Decision Matters More Now Than It Used To

If you look at older Brisbane homes, their electrical loads are often quite light compared to what we expect in a new build today.

Over the past decade, the way we use power at home has changed significantly.

Bigger and more constant electrical loads

Modern homes regularly run:

Ducted, whole-house air-conditioning
Large fridges and freezers
Induction cooktops and sometimes double ovens
Multiple TVs, computers, devices and home office setups
Laundry appliances, dryers and often extra fridges in the garage

On a hot summer’s afternoon in Brisbane, it’s not unusual for a new home to have:

The ducted air-conditioning going
The oven and cooktop running for dinner
The dishwasher on
The washing machine spinning
Multiple screens and devices in use all at once.

That is a very different picture to the smaller, less equipped homes of decades past.

Solar power becoming standard

In South East Queensland, solar is no longer a luxury. For many people building a new home, it’s either:

installed from day one, or
planned for in the near future.

With Brisbane’s strong sunshine, solar is an obvious way to reduce ongoing power bills. But solar also changes the way your home interacts with the grid:

Instead of just using power, your home is now also generating and exporting power.
Larger solar systems and more capable inverters are becoming common.
This extra generation and export is handled more comfortably when the home’s power supply is well designed – and often that means 3 phase.

Batteries gaining popularity

More households are now looking at battery storage to:

Use more of their own solar power in the evenings
Reduce reliance on the grid
Increase resilience during outages.

Batteries can move a lot of energy in and out of your home over short periods. Having a well thought-out power supply – particularly 3 phase for homes with larger systems – helps ensure this is handled reliably and efficiently.

Electric vehicles and EV chargers

Even if you don’t own an electric vehicle yet, there’s a good chance you’ll consider one over the next 5–10 years.

EV charging is a high electrical load. Some chargers are designed to run on single phase, but many perform best with 3 phase, especially when you want faster charging without overloading the rest of the house.

Homes by Markon can design your new custom home with future EV charger provisions as an extra, so when you’re ready to add a charger, your home’s electrical system is already prepared.

Higher expectations for comfort and efficiency

Today, people expect new homes to be:

Comfortable year-round
Energy efficient
Cheaper to run over time.

Design decisions like a white Colorbond roof make a big difference here. A white roof reflects much more heat than a dark one, reducing the amount of heat that gets into your home. That means:

Your air-conditioning doesn’t have to work as hard
Your cooling costs can be lower
Your solar and battery systems can be used more efficiently.

Once you layer in ducted air-conditioning, solar, batteries and future EV charging, the question of single phase vs 3 phase power becomes one of the most important “behind-the-scenes” design decisions in a new custom home.

Why Power Companies Often Prefer 3 Phase for New Homes

As our streets fill with more air-conditioning, more solar, and more EVs, the electricity grid itself is under more pressure and complexity.

From a power company’s point of view, 3 phase power:

Helps spread demand more evenly
Helps spread solar export more evenly
Reduces stress on any one part of the network.

Better load balancing

Think back to the road analogy.

With single phase, a lot of houses might be crowding into one lane.
With 3 phase, the network can effectively spread that traffic across three lanes.

This balancing becomes especially important where:

Many homes have large ducted air-conditioning systems
Solar systems are feeding power back into the grid at the same time
EV chargers are drawing high loads in the evening.

Handling high-demand homes more safely

New custom homes with:

Whole-house air-conditioning
Strong solar input
Multiple large appliances

can place substantial demand on the network.

3 phase power helps share this demand and reduce the risk of overloading a single phase. In some newer estates or certain situations, power companies may:

strongly recommend, or
require

3 phase connections for particular types of new homes or higher loads.

Homes by Markon works with electrical designers, electricians and supply authorities to ensure each new custom home is designed with the right power supply, in the right way, from day one.

The Benefits of 3 Phase Power for Your New Custom Home

So how does this all play out in real life for someone building a new home in Brisbane or South East Queensland?

Here are the key ways 3 phase power can benefit your new build.

1. More capacity for real-world modern living

3 phase power gives your home more “room” to handle multiple heavy loads at once.

This is especially valuable if your new home will have:

Ducted air-conditioning throughout
A large kitchen with multiple appliances
A bigger laundry setup
The potential for EV charging, a workshop, or other power-hungry additions later.

Instead of constantly worrying about overloading circuits, 3 phase helps ensure your home can comfortably run everything you need during busy times – like those hot summer evenings when the whole family is at home.

2. Better performance for whole-house air-conditioning

For many families, comfort is a major factor in building a new custom home. Ducted air-conditioning across the whole home is very popular in Brisbane and SEQ.

Many larger, more capable ducted systems are designed to run on 3 phase. The benefits include:

Smoother starting and running of large compressors
Reduced chance of voltage drop or strain when the system kicks in
More reliable performance during extreme heat periods when demand is highest.

Combine this with a white Colorbond roof, good insulation and thoughtful home orientation, and you end up with:

A home that stays more comfortable
An air-conditioning system that doesn’t have to work as hard
Potentially lower running costs over the life of the home.

3. A better match for solar and battery systems

Solar and batteries are where 3 phase really becomes attractive for many new builds.

Larger and more capable solar systems

3 phase power often allows:

The use of 3 phase solar inverters
Better distribution of solar generation across all three phases of your home’s supply.

This can help:

Smooth out how solar power is used within the home
Reduce the risk of voltage issues on a single phase
Improve the reliability of solar export back to the grid.

In some cases, the size of the solar system or inverter capacity you’re allowed to install may be influenced by whether your home is on single phase or 3 phase. Being on 3 phase can give you more flexibility and options.

Batteries that work efficiently with the home

As batteries become more common, a well-designed 3 phase power setup:

Makes it easier for the battery to charge and discharge effectively
Helps spread that activity across the home
Reduces the load on any one phase.

Homes by Markon designs your home to be solar and battery ready, working closely with trusted partner installers who specialise in the systems themselves. Together, we ensure your switchboard, wiring and roof design are set up to make the most of your chosen solution – and to support future upgrades.

4. Future-proofing your investment

A new custom home isn’t a short-term decision. You’re building for the next decade or two – possibly longer.

3 phase power gives you:

More flexibility to add or upgrade electrical features in the future
Less need for expensive electrical upgrades later on.

Examples of future changes that 3 phase supports well include:

Adding or upgrading EV chargers (as extras)
Increasing your solar system size (subject to local rules)
Installing or upgrading a battery system
Adding a workshop with more demanding power tools
Adding spa or heat pump equipment.

Rather than designing a home that’s just adequate for today, 3 phase helps prepare your home for the lifestyle and technologies of tomorrow.

Pros and Cons: Single Phase vs 3 Phase

To make things clearer, it’s helpful to look at the pros and cons of each option side by side.

Single Phase – Pros

Often slightly cheaper to connect or keep as the standard option.
Perfectly adequate for smaller homes with modest electrical requirements.
Simple and familiar arrangement; many existing homes are already on single phase.

Single phase can work well if:

You’re building a relatively compact home
You don’t plan on whole-house ducted air-conditioning
Your solar system will be modest
You have no plans for EV charging or other high loads.

Single Phase – Cons

Limited capacity compared to 3 phase. As you add more high-demand appliances, the risk of overloading increases.
May restrict your options for larger ducted air-conditioning systems.
Can limit the size or performance of solar and battery systems, depending on local inverter and export rules.
Offers less flexibility for future additions like EV chargers, spa equipment or larger expansions of your electrical setup.

3 Phase – Pros

Much greater electrical capacity for your home overall.
Handles whole-house ducted air-conditioning and multiple large loads more comfortably.
Often a better match for larger solar systems and battery setups.
Helps integrate your home more smoothly with a grid that’s handling increasing amounts of solar and high-demand appliances.
Excellent future-proofing, allowing you to adapt as your lifestyle and technology needs change.

For many new custom homes in Brisbane and SEQ – especially medium to large homes with strong comfort and solar goals – 3 phase is increasingly the most sensible choice.

3 Phase – Cons

Usually a higher upfront connection cost than basic single phase.
The metering and switchboard design is a little more complex (though this is all handled by your builder and electrician).
Requires thoughtful load balancing across the three phases – which is part of the design work Homes by Markon coordinates.

Overall, while 3 phase can cost a bit more initially, it often provides significant benefits in comfort, flexibility and long-term value.

How Homes by Markon Designs Your New Home With Power in Mind

Choosing between single phase and 3 phase isn’t something you should be left to decide on your own after the house is designed. It needs to be considered early, when your layout, roof design and mechanical services are being planned.

Homes by Markon takes a holistic approach to this.

Understanding how you’ll live in the home

During the design stage, we look at how you intend to use your new home:

How large will the home be?
Are you planning ducted air-conditioning throughout?
How important are low ongoing power bills to you?
Are you planning solar from day one, or do you want the home to be solar-ready?
Do you see a battery system in your future?
Is there a possibility of owning an EV, or multiple EVs, down the track?
Are there any special loads – like workshop tools, gym equipment or spa systems – you want to allow for?

These answers help guide whether single phase will be sufficient, or whether 3 phase is clearly the wiser option.

Designing for comfort, efficiency and future upgrades

We then design your home around those goals, bringing together:

A white Colorbond roof for better heat reflection and lower cooling loads
Well-planned insulation and orientation
Ducted air-conditioning sized correctly for your home
Electrical infrastructure that matches your current and future needs.

For solar and batteries, we:

Design the roof layout and switchboard to be solar and battery ready
Work with trusted partner installers who specialise in these systems
Coordinate the details so your power supply, inverter, and any future battery can work together effectively.

Whether you choose single phase or 3 phase, the aim is always the same: a home that is comfortable, efficient and ready for what’s coming next.

Real-World Style Examples

To make the difference more tangible, it helps to imagine a couple of scenarios.

Example 1 – Single phase feeling the strain

A couple builds a new home on single phase. At first, they have:

A few split system air-conditioners
A standard electric cooktop and oven
A single fridge, TV and basic appliances.

Over time, as their family grows, they:

Install a larger air-conditioning system
Add a second fridge in the garage
Upgrade to an induction cooktop
Add a decent-sized solar system
Eventually buy an EV and want a charger.

Suddenly, the electrical demand is much higher. Circuit breakers trip more often, and the limits of the single phase supply become more obvious. At that point, upgrading to 3 phase can be more complex and disruptive than simply designing the home for 3 phase from the beginning.

Example 2 – 3 phase from day one

Another family builds a new custom home in Brisbane with Homes by Markon.

From the start, their home is designed with:

3 phase power connection
A white Colorbond roof and good insulation
Whole-house ducted 3 phase air-conditioning
A generous solar system installed by a partner company
Provision in the switchboard and wiring for a future EV charger as an extra.

The home handles Brisbane’s hot summers comfortably. The solar system operates efficiently, exporting power smoothly. When the family decides to add a battery or EV charger in a few years, the underlying power supply is already capable of supporting it.

The difference isn’t just technical – it’s about how easy and comfortable life in the home feels, both now and in the years ahead.

How to Decide Which Option Suits Your New Custom Home

So, where does that leave you when you’re planning your own build?

You don’t need to know everything about voltages, phases and inverters. You simply need to be honest about:

The size and style of home you’re building
The comfort you expect (especially with air-conditioning)
How important solar and energy efficiency are to you
What you might want to add in the future.

When you should seriously consider 3 phase

3 phase is very much worth considering if your new home will:

Be medium to large in size
Have ducted or whole-house air-conditioning
Include a larger solar system now or soon
Possibly have a battery system in future
Include or plan for EV charging
Or if you simply want to keep your options open with minimal limitations.

When single phase might still be suitable

Single phase may be enough if:

The home is relatively small
Cooling needs are modest
You’re not planning significant solar, battery or EV charging
Your current and future electrical demand is clearly within what single phase can comfortably handle.

The important thing is to have this discussion early with your builder and your electrical team, rather than leaving it as a default or an afterthought.

Start Your Custom Home Conversation With Homes by Markon

Single phase and 3 phase power both have their place. But with the way we now live in Brisbane and across South East Queensland – bigger air-conditioning, more solar, more devices, and the rise of EVs – 3 phase power is increasingly the smarter, more future-focused choice for many new custom homes.

The best time to make this decision is at the design stage, when we’re planning your layout, your roof, your air-conditioning and your solar.

You don’t need to have all the technical answers – that’s what we’re here for. What matters is that your home is comfortable, efficient to run, and ready for whatever you want to add in the years ahead.

If you’re starting to plan a new custom build and want to get the power, comfort and efficiency right from day one, we’d love to talk.

Start your custom home conversation with Homes by Markon.

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