Let's pretend I bought a house for $400K in the 1990s in San Francisco.
Let's pretend Zillow thinks it is now worth $1.5MM in the late 20teens.
Now lets pretending I have a decent enough memory to sum up the ownership costs.....
Lets start subtracting 25 yrs of prop tax, say $4.5K a year, so minus $113K
Lets subtract off two house paintings and some inside painting, say minus $30K.
A new roof means another $25K gone, oh wait, what about the temp roof we put on ourselves a year after we bought the house (ooo, my back), minus $5K.
Electrical upgrade is minus another $5K.
Copper pipe is another $6K.
New fences is $7K
Yardwork, plants, etc, over the years, $5K
Insurance is $2K a year, so $50K there
And last years big job, say $203K
That is $449,000 of upkeep.
So, if I sold today and got $1.5 million, then subtract off cost to purchase of $400K, then another $449, I have a net profit of $651K (this number is an approximation because I am not including purchasing costs, purchase tax, fees, no real estate mortgage write offs for my taxes, and probably any number of other items).
So, on the net side, no, I do not live in a million dollar house.