Replacing old windows might seem straightforward—pick a style, place the order, and get them installed. But it’s rarely that simple, especially if you’re renovating an older home where nothing is quite “standard.”
The truth is, making the wrong call on something as seemingly minor as window sizing or frame material can quickly lead to blown budgets, poor performance, and a finish that doesn’t do your renovation justice.
To help you avoid those costly regrets, here are five common mistakes people make when buying replacement windows—and how to make sure you get it right from the start.
Assuming Stock Sizes Will Fit Your Home
One of the biggest traps renovators fall into is the belief that standard-size windows will slot straight into an older home. But homes built before modern sizing became the norm often have openings that don’t match today’s standard dimensions.
Trying to make a stock window fit can lead to unexpected (and expensive) work—rebuilding walls, reframing openings, or compromising on the internal finish. What looked like a cheaper option on paper can quickly blow out your renovation budget.
That’s why custom-sized aluminium windows are often the smarter choice. They’re made to fit your exact openings, which means a cleaner install, a better-looking result, and no hidden construction costs creeping up down the track.
Choosing the Wrong Frame Material for Your Climate
Not all window frames are built to handle Australian conditions. Timber might look beautiful on day one, but in hot or coastal areas, it’s prone to warping, cracking, and rot—especially without regular maintenance. It also invites pests like termites, which no homeowner wants.
uPVC, while often marketed as a low-maintenance option, can become brittle or discoloured over time under strong UV exposure—something that’s hard to avoid in most parts of Australia.
Aluminium, on the other hand, holds its shape, doesn’t fade, and shrugs off the elements. It’s a proven performer in harsh climates, offering a reliable, long-lasting frame with very little upkeep—perfect for renovators who want it done once and done right.
Overlooking Energy Efficiency (and Missing Out on Savings)
New windows should do more than just look good—they should help your home perform better too. But if you choose the wrong glass or overlook insulation, you could be letting hot air in during summer and warm air out during winter.
Basic single-pane windows or poorly sealed units offer little thermal protection. Over time, that adds up to higher power bills and a home that’s harder to keep comfortable.
For a smarter investment, look for features like double glazing, thermal breaks in the frame, and tight seals. These details make a big difference in reducing heat transfer, keeping your energy costs down, and improving your home’s resale appeal.
Picking the Wrong Style for Your Home
Windows do more than let in light—they define the look and feel of your home from the outside in. Get the style wrong, and even a well-executed renovation can feel mismatched or unbalanced.
A common mistake is choosing frames or finishes that clash with your home’s existing architecture. Thick, dated profiles can look out of place on a sleek modern façade, while overly contemporary designs can jar with character homes.
Slimline aluminium frames offer the flexibility to do both. They suit modern homes perfectly but can also be custom-sized and configured to match older styles—so you can upgrade performance without sacrificing the original character.
The right window style adds value. The wrong one just adds regret.
Forgetting About Bushfire Compliance
If your home is in a bushfire-prone area—a common reality across much of Australia—you can’t afford to overlook compliance. Building codes often require BAL-rated (Bushfire Attack Level) windows that meet strict fire safety standards.
The mistake? Assuming all windows are compliant by default. They’re not.
Before you buy, check that your replacement windows meet the necessary BAL rating for your zone. Aluminium frames paired with toughened or double-glazed glass are often an easy way to tick that box, giving you added safety without overcomplicating your reno.
Skipping this step could mean costly replacements—or worse, failing a final inspection.
Conclusion
Replacing your windows is one of the smartest ways to improve your home—but getting it wrong can cost more than you think. Whether it’s underestimating the value of custom sizing, overlooking bushfire compliance, or choosing the wrong material for your climate, these mistakes are easy to avoid with a bit of forward thinking.
If you’re seeking aluminium windows in Perth for your renovation, Ross’s Discount Home Centre offers a range of durable, low-maintenance custom and stock options designed to suit both modern and traditional homes.