Where to Start When Your House Is Freezing in Winter and Boiling in Summer?

If you’re constantly reaching for the heater in winter or cranking the air con in summer—and your energy bills are skyrocketing because of it—you’re not alone. Many Australian homes, especially older ones, simply don’t perform well when it comes to thermal comfort. You might be asking: Should I replace my windows? Add solar panels to reduce my bills? Maybe insulate the roof better? The truth is, without knowing what’s actually causing the problem, you could end up spending money in all the wrong places.

This is where a Passive House Architect can be your greatest asset. Rather than guessing where to begin, we start by measuring how your house is currently performing. Using professional tools like the Passive House Planning Package (PHPP), we model your home and calculate how much energy is required to keep it warm in winter and cool in summer. This thermal analysis highlights the weakest points in your building envelope—whether it’s your windows, roof insulation, air leakage, or all of the above.

example of thermal calculations

With this data, we then run simulations to test different upgrade strategies, such as swapping out your single-glazed windows for double glazing, or adding insulation to your roof and walls. But here’s the important part: we also model the cost versus comfort impact of each change. For example, we might find that adding roof insulation has more benefit per dollar than upgrading your windows—helping you prioritise the best actions for your budget.

Why is this so important? Because nearly 50% of a typical household’s energy bill goes towards heating and cooling, and we spend up to 90% of our time indoors. Making our homes more comfortable and energy-efficient isn’t just a financial decision—it has a direct impact on our daily wellbeing. A home that maintains a stable indoor temperature can improve sleep, concentration, and even reduce the risk of illness caused by cold drafts or overheating.

Lastly, your home is likely the most valuable long-term investment you will ever make. Understanding where to invest in upgrades, and the return on those upgrades, is critical. By modelling the performance of your existing home and assessing the risk and benefit of each improvement, you’ll have a clear, confident path forward—rather than a series of expensive, piecemeal renovations that may or may not deliver results.

So before you change a single window or install another duct, speak to a Passive House Architect. A smarter, more efficient, and more comfortable home starts with the right information.