Living in a two-storey home has its perks — but keeping both levels evenly cool in summer (or warm in winter) isn’t always one of them.
If you’ve ever walked upstairs in January and felt like you’ve entered a sauna, you’re not alone. Heat rises, air doesn’t circulate evenly, and many older homes on the South Coast weren’t built with air conditioning in mind.
So the big question is: what’s the best air conditioning system for a two-storey home? Do you go ducted? Multiple splits? A hybrid of both? Or something entirely different?
At Chilko AIR, we’ve installed hundreds of systems across two-storey homes in Nowra, Culburra, Callala Bay, and beyond. And while there’s no universal answer, there is a right fit for your layout, usage, and budget.
In this blog, we’ll break down the options, the trade-offs, and how to make the smartest decision for your home — not just for summer, but year-round comfort.
Why Two-Storey Homes Need a Bit More Planning
Cooling a two-storey home isn’t just a matter of buying a bigger unit. The vertical layout creates challenges that single-storey homes rarely deal with — and without the right system design, you’ll likely end up with hot bedrooms, cold downstairs zones, and higher energy bills.
Here’s why two-storey layouts need more consideration:
Heat Rises — and Stays Upstairs
It’s common to see a big temperature difference between floors. During summer, warm air naturally rises, leaving upstairs rooms uncomfortably hot at night while the downstairs remains cooler. This makes upstairs bedrooms especially tricky to keep comfortable.
One System Doesn’t Always Do It All
While a single ducted system can cover both levels in some homes, it depends on ceiling access, room usage, and how easily ducts can be run between floors. In other cases, a mix of ducted and split systems works better.
Zoning Becomes More Important
In a two-storey home, you likely don’t want to cool the whole house at once — especially if everyone is downstairs during the day and upstairs at night. Smart zoning allows you to cool only the areas you’re using, improving both comfort and efficiency.
Older Homes May Lack Roof Access
In many South Coast homes, the upper floor has little to no roof cavity — especially in split-level or loft-style designs. This limits the ability to run ducting and may steer the design toward split or multi-split systems instead. See more on this in our recent blog, installing a ducted system in an old home.
Planning for a two-storey system starts with understanding your home’s layout — and choosing a solution that balances performance, control, and cost.
Can You Use Ducted Air Conditioning in a Two-Storey Home?
Yes — ducted air conditioning can work in many two-storey homes, but whether it’s the right fit depends on how your home is built and how you use it.
When Ducted Works Across Both Floors
In some homes — particularly newer builds or larger homes with good roof access — it’s possible to run a single ducted system across both levels. We usually install the indoor unit in the roof space above the upper floor, with ducting dropped down into downstairs rooms and run laterally across the top floor.
This setup allows for clean, invisible air distribution throughout the home with minimal visual impact. It’s ideal if you want full climate control with no wall units.
The Role of Zoning
Zoning is essential in two-storey ducted designs. It lets you divide the home into separately controlled areas — typically upstairs and downstairs, plus bedrooms and living zones. That way, you’re not wasting energy cooling both levels when only one is in use.
Smart controllers (like MyAir or AirTouch) make this even more efficient, allowing you to schedule zones or adjust them remotely.
Consider Ceiling Space and Access
One of the biggest limitations is ceiling cavity space — especially above the ground floor. If your lower level has no roof access, we’ll assess whether ducting can be run through wardrobes, bulkheads, or side cavities. In some homes, this can be done cleanly. In others, it may be more practical to use a combination of systems (more on that next).
Ducted systems work brilliantly in two-storey homes — but only when the layout allows it. If not, there are other options that offer similar comfort and control.
Are Split Systems Better for Upstairs Bedrooms?
In many two-storey homes — especially older ones or those with limited ceiling space — split systems are the most practical option for cooling upstairs bedrooms.
Why Splits Work Well Upstairs
- No roof cavity needed: Split systems mount on the wall and only require a small pipe run to the outdoor unit. That makes them ideal for upper floors with no ceiling access.
- Individual temperature control: Each bedroom can be set to its preferred temperature — which is great for families with different comfort needs.
- Lower upfront cost (in some cases): Installing individual splits can be more affordable than modifying the entire home for ducted air.
When We Recommend a Mixed Setup
For two-storey homes where ducted isn’t practical across both levels, we often recommend a hybrid setup:
- Ducted aircon for the ground floor living areas
- Split systems for upstairs bedrooms
This gives you strong, quiet performance where you spend most of the day (downstairs), and precise control at night (upstairs), without the need for major structural changes.
It’s a smart way to get whole-home comfort — especially in homes that weren’t originally built with air conditioning in mind.
What About Multi-Split Systems?
If you’re trying to avoid multiple outdoor units but still want room-by-room control, a multi-split system might seem like the perfect middle ground. But like any option, it comes with pros and cons — especially in two-storey homes.
What Is a Multi-Split System?
A multi-split system allows you to connect multiple indoor units (like wall-mounted splits or bulkhead cassettes) to a single outdoor unit. Depending on the brand, you can usually connect between 2 and 5 indoor heads to one compressor.
Pros in Two-Storey Homes:
- Reduces outdoor clutter — only one external unit, even with multiple indoor heads.
- Independent control — each room can be run at a different temperature or turned off when not needed.
- Ideal when ducted isn’t feasible — works well in homes with minimal ceiling or roof space.
Cons and Considerations:
- More complex installation — especially when indoor units are split across two levels. Long pipe runs and elevation changes can increase labour and cost.
- Running multiple zones at once can be less efficient — especially if all indoor units are calling for different temperatures at the same time.
- Limited capacity — not always suited for large open-plan living spaces, which may be better handled by ducted or larger split systems.
We typically recommend multi-split systems for smaller two-storey homes, dual-occupancy dwellings, or where external space is limited and aesthetics are a priority. For large homes with multiple living zones, a ducted system (or a ducted/split combo) may be more effective.
Running Costs and Energy Efficiency
Choosing the right system for your two-storey home isn’t just about comfort — it’s also about how much it’ll cost to run over time. And that varies depending on the system type, how you use it, and how your home is set up.
One Large System vs Two Smaller Ones
In homes where ducted can service both levels, one well-zoned system is often more energy-efficient than running multiple splits across the house — especially if you can shut off unused zones during the day or night.
However, if your layout doesn’t support a single system, two smaller systems (e.g. ducted downstairs and splits upstairs) can be just as efficient — as long as they’re inverter-driven and correctly sized.
Zoning = Smarter Savings
In two-storey homes, zoning plays a huge role in energy efficiency. The ability to cool only the bedrooms at night, or just the living areas during the day, prevents wasted energy and helps reduce your power bills. We always recommend smart controllers for this reason — they make zoning easy and intuitive.
Modern Inverter Tech
Whether you go ducted or split, make sure your system uses inverter technology. It allows the system to ramp up and down as needed, rather than cycling on and off — which uses far more power.
App Control and Scheduling
Smart systems (like MyAir, AirTouch, or even branded split system apps) help you control temperature, zone use, and timing remotely. This helps avoid running the system when no one’s home — one of the biggest culprits of wasted energy.
How We Design Systems for Two-Storey Homes on the South Coast
At Chilko AIR, we’ve installed air conditioning systems in two-storey homes from St Georges Basic to Nowra to Culburra Beach — and no two layouts are ever the same. That’s why we never offer one-size-fits-all solutions.
Here’s how we approach it:
We Start With a Site Inspection
Before quoting, we visit your home to assess:
- Ceiling and roof cavity access
- Return air and ducting options
- Zoning opportunities
- Electrical requirements
- How you actually use your home — not just how it’s built
This ensures the system we recommend matches both your layout and your lifestyle.
We Recommend Systems Based on Structure + Usage
- For homes with good roof access and open plans: ducted across both levels, with zoning
- For homes with tight ceilings upstairs: ducted downstairs + split systems upstairs
- For space-constrained homes or townhouses: multi-split systems for targeted control
We Explain the Trade-Offs
Some homes can technically support ducted across both floors — but that doesn’t always mean it’s the best option. We’ll explain when it’s worth the cost, and when you can get better value with a hybrid setup.
And We Keep It Transparent
Every quote includes clear pricing, timeframes, and optional upgrades. No fluff, no surprises, and no pressure — just what will actually work best for your home.
