I've been involved in residential construction in the Illawarra for long enough to have seen most things go wrong. The surprises come less often now, not because problems have become rarer, but because the same problems keep recurring. The same mistakes, made by different homeowners, on different projects, in different suburbs, with different builders. Over and over.
What's striking is that these aren't naive mistakes. The homeowners who make them are usually intelligent, educated, and financially capable people who have done their research. They've read articles, asked friends, attended open homes, and thought carefully about what they want. They've just been let down by an information gap — the gap between what they know and what the industry knows — that nobody in the industry has much incentive to close.
This article is my attempt to close a portion of it. Here are the five mistakes I see most often, why they happen, what they cost, and what you can do differently.
The most consistently damaging mistake in residential renovation isn't made on site or in a contract. It's made at the kitchen table, months before construction begins, when a homeowner decides what their project is going to cost based on: an online calculator, a rough comment from a builder at an open home, a neighbour's project from three years ago, or simply a number that feels achievable. These aren't malicious estimates. They're just wrong. Renovation costs in the Illawarra in 2025 are specific to your site, your design, your specification, and current market conditions. The damage comes when the budget-setting step is skipped or done casually, because every subsequent decision is made in reference to a number that doesn't reflect reality.
This one is almost universal. Homeowners choose architects and building designers based on: a beautiful Instagram feed, a word-of-mouth recommendation from someone whose project was completely different, whoever the builder suggested, or whoever responded first to an enquiry. None of these methods assess whether a designer is actually right for your project. What matters when choosing a designer is specific: have they designed comparable projects on similar sites? Do they design to budget consistently? Are they familiar with Wollongong City Council's planning controls — not just in general, but for your zone, your overlay constraints, your property type?
Building contracts are long. They're written in legal language. By the time they arrive, you're excited, you've been waiting months, and the last thing you want to do is spend three evenings reading a 40-page document that you're not sure you'll understand anyway. So most homeowners skim it, feel vaguely comfortable, and sign. The problem is that the contract is the document that governs every difficult moment of your construction: every variation, every delay, every dispute, every payment. Standard HIA and MBA contracts are not predatory, but they are written by organisations that represent builders. Where there is ambiguity, it typically resolves in the builder's favour.
This is perhaps the most costly belief in residential construction — the assumption that because council or a certifier is involved, the quality and specification of the work is being independently verified throughout the build. It isn't. Your certifier checks that construction complies with the Building Code of Australia and your development consent conditions. They do not check whether the work matches your drawings, whether the specification is being followed, whether PC items are being substituted without your knowledge, or whether workmanship meets a reasonable quality standard. Without independent stage inspections, defects get covered up by the next trade. These things happen, not because builders are routinely dishonest, but because they're managing multiple projects, subcontractors are under time pressure, and nobody is checking.
The final payment is the most powerful piece of leverage a homeowner has over their builder. It's also the one most commonly surrendered without using it. By the time practical completion arrives, homeowners are exhausted. They've been living through a construction project for months, often in temporary accommodation or in a partially completed house. The builder says it's done. The keys are ready. All you want is to be in your home and for this chapter to be over. And so, despite the list of things that still need fixing, you pay. The right approach is to complete a thorough defects inspection before accepting practical completion, document every item specifically and in writing, and hold the final payment until significant defects are rectified and verified.
Tell us where you are in the process — planning, design, tender, or mid-build — and we'll tell you honestly what the most important thing to focus on is right now.