How Westside Homeowners Are Misreading Their Net Worth

When Zillow's own former CEO, Spencer Rascoff, sold his Seattle home in 2016, the price came in 40% below what his own company's Zestimate said it was worth. If the person who ran the company built on that algorithm couldn't trust it on his own house, that's worth pausing on.

Zillow publishes its own error rate. The nationwide median is 7.01% on off-market homes, meaning half are off by more than that. On a $3M Mar Vista home, that's a $210,000 swing before anyone walks through the front door. And it's not a rare miss, roughly 1 in 6 off-market Zestimates land more than 20% away from the eventual sale price.

The algorithm struggles on the Westside in particular because our housing stock isn't uniform. A single Mar Vista block might hold a 1948 original, a 2018 spec build, and a remodel from the seventies, three very different prices on the same street. Zillow can't see the kitchen that needs gutting or the neighbor's new ADU. It averages comparables, and on a unique property, that math falls apart.

The good news is you can get a much closer read in about five minutes. Here's how I do it for clients, simplified down to the parts a homeowner can run on their own.

The 5-Minute Exercise

Start with closed sales only. Pull three closed sales from the last 90 days, either on your street or within a few blocks. List prices are largely fiction right now, about 18% of existing-home listings carried a price cut as of late 2025. The ask is a starting offer. The sold price is the truth.

Match like with like. Stay within about 10-15% of your square footage. Same bed and bath count. Similar lot and condition tier. If you can't find three close matches, widen the radius before you widen the criteria. Proximity matters less than people think, but comparability matters more.

Be careful with price per square foot. It's the most misused number in home valuation. Smaller homes almost always trade at a higher price per foot than larger ones. A 2,000-square-foot home in Venice can trade at $1,500 a foot while a 4,500-square-foot home on the same block trades at $1,100. Apply the wrong number to your own square footage and the result is off by hundreds of thousands.

Weigh condition honestly. Zillow's own research shows turnkey homes sell for about 2.9% above expectations, while fixer-uppers sell for about 14% below. On a $4M Westside home, that gap is roughly $650,000 of real money. Buyers in this price range are time-poor and cash-rich, and they'll pay a meaningful premium for a house they can move into on Saturday.

Check days on market. If your comps closed inside two weeks, the sale prices are reliable signals. If they sat 60, 90, or 120 days with price cuts along the way, the final sale price is what buyers will actually pay, the original ask was wishful thinking.

What I See Homeowners Get Wrong Every Week

A few patterns show up again and again. Anchoring to the highest sale on the block is the most common, when a spec build sells at the top, every original on that street suddenly feels worth the same number, and it almost never is. Ignoring condition is the second. The third is treating the Zestimate as a ceiling when it's often a floor, which means a lot of Westside owners have been quietly under-pricing their own net worth in their heads for years. That changes how you borrow, how you plan retirement, and whether a 1031 exchange belongs on the table.

The five-minute version gets you most of the way. It doesn't get you the last 5 to 10%, and on a Westside home, that's the part that actually matters when you're making a real decision. Closing that gap is what twenty years of walking these houses and sitting across from the buyers writing the checks is for.

FAQ

Why is the Zestimate less reliable on the Westside than in other markets?
Because Zillow's model relies on comparable sales, and Westside blocks often mix eras and renovation levels on the same street. A 1948 original next to a 2018 spec build gives the algorithm two very different data points to average, which flattens both prices toward the middle.

How accurate is Zillow's Zestimate, according to Zillow itself?
Zillow reports a median error rate of 7.01% on off-market homes, meaning half of all estimates miss by more than that. Roughly 1 in 6 off-market Zestimates miss by more than 20%.

What's the fastest way to check my home's value myself?
Pull three closed sales (not list prices) from the last 90 days within a few blocks, match them to your home on size, bed/bath count, lot, and condition, and check how long they sat on market before selling. That gets you close in about five minutes.

Why shouldn't I use price per square foot from a different-sized home?
Smaller homes consistently trade at a higher price per square foot than larger ones. Using a smaller comp's per-foot number on a larger home, or vice versa, can throw off the estimate by hundreds of thousands of dollars.

How much does condition actually affect sale price?
On Zillow's own data, turnkey homes sell for about 2.9% above expectations and fixers sell for about 14% below. On a $4M home, that's roughly a $650,000 spread.