Northern Beaches Mums Group
Northern Beaches Mums Group

Found your perfect home? The pre-purchase checklist for before you sign on the dotted line

by Kevin Yau

You’ve found your dream forever home. It’s easy to picture the whole life you’ll build there and it’s just as easy to let that excitement carry you straight past the red flags.

The stats show why you should look a little bit closer at that dream home, before you commit to making an offer. Research from UNSW found up to 85% of new apartment buildings in Sydney have at least one significant defect, while government data shows that a quarter of established properties also face issues.

With fixing a failed bathroom membrane or a leaking balcony running anywhere from $8,000 to $35,000, it’s worth taking an extra 15-20 mins to look more closely at that dream home.

The good news is that most of the warning signs are things you can check at the initial open house, before you make an offer and do the pre-purchase building inspection.

We’ve spoken to the experts and put together this checklist covering the things families most often miss.

A few plumbing checks can save you long term

Kevin Yau at The Clean Plumber says families most often focus on ticking off their own checklist of preferences and features and skip important details about the plumbing during the open home.

  • Run the taps to check for blockages – turn on the kitchen sink and the shower at the same time. If the pressure drops noticeably, it can mean undersized pipes or a blockage further down the line. It’s worth asking about this before you commit.

  • Listen for knocking in the walls – turn a tap off quickly and listen for banging in the walls. That’s a water hammer, and it can point to pressure issues or pipework that’s come loose over time.

  • Flush all toilets – a slow or gurgling drain is often a sign of a blockage deeper in the sewer line, not something you want to inherit.

  • Check under the sink – look for rust on pipes, dampness, or water staining in the cabinetry is often the first visible sign of a slow leak that’s been going on for a while.

  • Check out the backyard –  a patch of grass that’s greener or growing faster than the rest of the yard especially in a dry spell can mean there’s a leaking underground pipe feeding it. If it’s been raining and water is pooling in one area it’s worth looking around for clogged drains.

Structure and moisture checks can identify red flags before making an offer

While building inspections will uncover any structural problems, our experts recommend checking for the following during the inspection for any red flags.

  • Check the wall on the other side of the shower head – bubbling paint or a rough, uneven texture on the other side of a shower wall usually means moisture is getting through the waterproofing. It’s one of the most common defects found after settlement.

  • Look out for musty smells in bathrooms or laundries – mold can establish itself inside wall cavities within 24 to 48 hours of sustained moisture, which is worth knowing when you’ve got little ones with developing lungs in the house. If a room smells damp with no obvious cause, it’s worth investigating.

  • Look at the way the backyard slopes – if the ground slopes toward the house rather than away from it, then water can pool against the foundations, which, over time, can mean cracking or structural movement.

  • Look for  white, powdery residue on brick or concrete – this is called efflorescence, a sign that water has been getting into the masonry and evaporating, leaving salts behind. It’s a strong indicator of ongoing water intrusion.

  • Look up for sagging ceilings – if you see any dip or sag in a ceiling it usually means water has been pooling above the plasterboard from a roof or plumbing issue and has weakened the material over time

Taking the extra 20 mins during the open house is worth it

You may think it can’t happen to you and this happens to only unlucky buyers. But data from Master Builders NSW states that the cost of rectifying building defects in NSW residential construction alone is estimated to exceed $1 billion annually. That’s a heavy cost facing families every day.

It’s not just apartments and new builds either. A quarter of established homes inspected in Australia show signs of structural cracking. This is a problem that is close to home with these defects often driven by the same clay soils and coastal air that is present in the Northern Beaches.. And with roughly 90% of inspected suburban properties having trees close enough to cause pipe or structural disruption, defects are closer to the norm than the exception.

That’s not a reason to walk away from a house you love. It’s a reason to walk through the open house with your eyes open.

This checklist is a starting point for what to look and listen for while you’re picturing where the kids’ beds will go. If anything on it raises a flag during an open home, it’s worth getting a professional opinion before the cooling-off period ends, not after you’ve signed.


This checklist was compiled with input from Kevin Yau, licensed plumber at The Clean Plumber, and expert sourced from Vital Building Inspection.