Lies, Damn Lies, Statistics

Unless you know about the data behind the data, most SF real estate charts probably doesn’t mean what you think they do. For example: Is a condo or a single family home in San Francisco more expensive?

We love data! We wrote a neighborhood by neighborhood guide to 2013 sales prices, crunched the numbers to compare MLS and off-MLS sales, and just today posted our 2014 Luxury Condo building survey. At this week’s sales meeting, the below graph was shared by the management team and I think it is a great example of how a chart usually raises more questions than it provides answers:

Condos vs SFR: Accurate or Not....?
Condos vs SFR: Accurate or Not….?

I had a few quick thoughts when I saw the above chart:

  • What about district 10?
  • How big?
  • BMRs?

District 10 is the most southern part of San Francisco, and essentially is the area south of 280 and north of the county line. It is home to some of San Francisco’s poorest and least-safe neighborhoods. The housing stock in District 10 is also almost exclusively single-family homes – I can think of one big condo project in the entire district….

The chart above also doesn’t take into account that single family homes are often larger than condo homes. Which leads to my charts!

Finally, I wasn’t sure if the above chart filtered out BMR and senior-only condos that have price or other restrictions that would weigh down the average condo price…

In my years of being a San Francisco Realtor, I’ve seen plenty of people actually prefer a condo to a single family home for a variety of reasons, and while I work with plenty of buyers that want a single family, I work with just as many people that are indifferent to condo or single family and a sizable number that don’t want a single family home.

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Based on my calculations, the median price for a condo is slightly higher than Zephyr computed – so those BMR and senior condos had brought the average down by a bit (about $20,000). And look – single family homes are bigger than condos! And look – if you take out district 10, it reduces the number of single family homes by 45, while the number of condos is only reduced by 4. In other words, District 10 is all about single family homes, and often single family homes at the lower end of the price range.
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In absolute price dollars, a single family is more expensive than a condo. But if we look at price per square foot, condos actually are more expensive. Across the city, the median price per square foot for a condo is about $917/square foot while a single family home comes in at $785/square foot.
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When we take out District 10, single family homes get a lot more expensive and condos are unchanged:image (4) On a price per square foot basis, taking out District 10 puts single family homes and condos almost on price parity. But condos still come out slightly more expensive on a price per square foot basis. image (6)

 

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