Comparables have to be genuinely similar to carry weight, and in Nutana that means matching era, lot size and renovation status, because an early-1900s home with an untouched interior is not a fair comparison to one that has been fully updated behind the same style of facade.
Documentation of the property's own condition helps just as much as the comparables. Photos of an unrenovated kitchen, an original electrical panel or unaddressed mechanical issues support an argument that the assessed value overstates what the home would actually sell for.
A factual error on the roll, a wrong finished area or an outdated room count, is the fastest kind of win and is worth checking before pulling any of the 3 to 4 comparables you would otherwise need. Get your hand-reviewed valuation from Joel Dyck.