I Built an Algorithm That Finds Underpriced Homes in Calgary. Here’s Exactly How It Works.
Every Calgary community has a price. Not one price — a relationship between price and size that shows up the moment you plot enough sold homes on a graph. Once you know that relationship, spotting a listing that’s priced below it takes about half a second.
That’s the whole idea behind my Deal Finder. I built it to do automatically what I’ve been doing by eye for years: compare an active listing’s price against what similar homes in that same community actually sold for, and flag the ones that don’t add up.
Right now it’s flagging active listings across more than 100 Calgary communities, updated every single day, and it’s free to use.
The Math Behind the Chart
For every community, I take the recent sold homes — detached, size and price — and fit a trend line through them. Bigger homes cost more, smaller homes cost less, and the line is the “expected” price for any given size in that community.
Then I draw a band around that line, ±10%. Anything inside the band is priced about where it should be. A listing sitting below the band — priced meaningfully lower than the trend says it should be for its size — gets flagged.
That’s the same trend line and the same shaded band on the scatter charts I’ve published for years on this site. The Deal Finder just turns “go look at 150 charts and find the dots below the grey” into a single list, sorted by how far below trend each listing sits, with the MLS number attached.
Real Data Has Real Problems — So I Went and Fixed Them
Here’s something most “automated deal finder” tools won’t tell you: the raw data lies to you in small, specific ways, and if you don’t catch it, your algorithm hands out false positives.
Two examples from building this one:
A listing in Huntington Hills was showing up as one of the biggest “deals” in the city — until I noticed it was a manufactured home priced against a trend line built mostly from site-built bungalows. Manufactured homes carry a completely different price-per-square-foot than a stick-built house next door, even in the same community. I went back through the data and found the field that actually identifies them (it’s not the one you’d expect — CREB frequently labels a manufactured home’s style as “Bungalow,” and only a separate structure-type field gives it away). Every manufactured home is now excluded from both the trend line and the flagged list.
A listing in Applewood Park looked like a 46% discount — the kind of number that should make you suspicious before it makes you excited. It turned out to be a court-ordered sale of one co-owner’s share in a jointly-owned property, which in Alberta usually means the list price reflects a fractional interest, not the full home. That’s not a deal. That’s a different kind of transaction entirely, and it’s excluded now too.
That’s the standard I’m holding this tool to: if a “deal” doesn’t survive a second look, it shouldn’t be on the list in the first place.
What You Actually Get
Every row on the Deal Finder gives you the MLS number, the address, beds, baths, year built, size, list price, what the trend line says it should be worth, and exactly how far below trend it sits — in dollars and percent. Click the community name and it takes you straight to that community’s active listings.
Some flagged listings are marked “Distressed” — probate, estate, court-ordered, power of attorney, bank-owned. Those aren’t excluded, because they’re still real opportunities. They’re just a different kind, and they can come with unusual closing conditions, so I flag them rather than hide them.
What This Isn’t
This is a screening tool, not a guarantee. A trend line only knows size and price — it doesn’t know about a cracked foundation, a bad roof, an ugly kitchen, or a lot backing onto a busy road. Every one of these listings is worth a closer look, not an offer sight unseen.
Older Calgary bungalows keep showing up disproportionately on this list, and that tracks — there’s a large supply of them across the city, they sit on land that holds its value, and they’re flexible: buy and hold, flip it, or move in yourself.
See It For Yourself
The list changes every day as new listings come on and old ones sell or get flagged out. Have a look at the Deal Finder and search your own community, or browse active listings by area over on 365yyc.com.
If you find something on the list and want a second opinion before you make a move — or if you’d rather I just walk you through what’s currently flagged in a specific community — call or text me at 403-831-0842, or reach out through JerryCharlton.com.
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