Of every deficiency I find in new build homes across Milton, Oakville, and the GTA, one stands above the rest in terms of cost and consequence: improper grading.
It's not the sexiest topic. It's not something that shows up in your kitchen or catches your eye during a walkthrough. But it is — by far — the most expensive problem I document. And it's the one your builder is least likely to mention.
What Is Grading and Why Does It Matter?
Grading refers to the slope of the soil around your home's foundation. In simple terms: water needs to flow away from your house, not toward it. The Ontario Building Code requires that the ground slope away from the foundation at a minimum gradient — typically 1 inch per foot for the first 6 feet.
When grading is done correctly, rainwater and snowmelt flow away from the foundation into the yard, swales, or storm drains. When it's done incorrectly — or settles after construction — water pools against the foundation wall. Over time, this leads to hydrostatic pressure against the foundation, basement moisture and humidity, efflorescence (white mineral deposits on basement walls), mould growth in hidden wall cavities, and in severe cases, foundation cracking and structural compromise.
Why It Happens in New Builds
In new developments across Milton, Halton Hills, Georgetown, and Oakville, builders are constructing dozens or hundreds of homes simultaneously. The lot grading is one of the final steps — and it's often done in a rush as the builder pushes to meet closing deadlines.
The soil used for final grading is frequently the same fill that was excavated during foundation work. It hasn't been properly compacted. It hasn't had time to settle. And in many cases, it hasn't been graded to the correct slope because the landscaping crew moved on to the next lot.
Over the first 6–12 months after construction, this loose soil settles — and the grade changes. What passed a quick visual check at the time of backfill may be directing water straight at your foundation by the time you move in.
This is why construction experience matters. I've supervised grading work on jobsites. I know what proper compaction looks like, what slope is sufficient, and where builders routinely cut corners on drainage. Most inspectors check the grade from the driveway. I walk the entire perimeter.
What It Costs to Fix After Closing
If the grading issue is caught during the PDI, the builder fixes it — usually within the first few weeks of possession, at no cost to you. But if it's not documented and you need to fix it yourself, the costs escalate quickly.
Simple regrading of a residential lot in the GTA runs $3,000–$5,000. If the issue has caused water infiltration and there's damage to the foundation or interior, remediation costs climb to $8,000–$15,000+. If hardscaping like driveways, walkways, or patios need to be removed and replaced to access the foundation perimeter, you're looking at even more.
All of this is preventable with a $299 inspection.
What I Check Specifically
During a new build inspection, I walk the full exterior perimeter and assess the grade at every point along the foundation. I look for negative grade (soil sloping toward the house), settled soil along the foundation wall, downspout discharge points that dump water too close to the foundation, window wells that lack proper drainage, and any evidence of standing water or erosion patterns.
I also check the lot relative to neighbouring properties to identify drainage patterns that may not be obvious from a single walkthrough. In new developments in Milton, where homes are built close together, water from one lot can affect the next — and that's something the builder's PDI representative will never bring up.
The Bottom Line
Grading issues are the most expensive and most commonly missed deficiency in new build homes in Ontario. They're invisible to the untrained eye during a PDI walkthrough. And they create damage that compounds over time if left unaddressed.
Having a professional inspector with construction experience walk your lot before you sign off is the single most effective way to catch this issue — and have the builder fix it at their expense, not yours.