

Bay Area Rental Price Heatmap by ZIP Code - stathack
http://kwelia.tumblr.com/

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jaggederest
This is fairly off topic, but as someone who has dabbled with GIS before, zip
codes mapped as geographic areas bother me.

"ZIP codes designate only delivery points within the United States and its
dependencies, as well as locations of its armed forces."

<http://en.wikipedia.org/wiki/ZIP_code>

So a zip code is more properly represented as an ordered point string or point
cloud, rather than an area. There exist zip codes with up to 11 non-contiguous
areas, zip codes which are valid only for the north half of an east-west
street, and other oddities. You can fudge this a little by just drawing
bounding boxes, but then you have up to 5 zip codes overlapping in some
places.

That bit of trivia aside, they do make sense from a real estate point of view
because a) all domiciles will have a zip code and b) it is usually freely
available on listings.

Generally though, it's better to translate any given address to a census tract
or census block group, since those divisions are actually defined as "a
geographic region defined for the purpose of taking a census" - they can be
properly mapped without ambiguity, crossovers, discontinuities, and other
boggling features of zip codes, (though not of course with _perfect_
regularity) and they also coordinate well with demographic data like median
income - I'd be very interested to see a graph of percent of median income per
square foot - I suspect you'd find some very 'hot' areas that don't seem like
it.

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wallflower
My dad always enthused about the Canadian system which is based on a six-
character string that is closer to Battleship-style coordinates:

[http://en.wikipedia.org/wiki/Postal_codes_in_Canada#Componen...](http://en.wikipedia.org/wiki/Postal_codes_in_Canada#Components_of_a_postal_code)

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coob
Yeah, wonder where they got that from…

<http://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom>

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pacaro
Aaah, fond memories.

The first hard algorithmic coding task I worked on was to generate isoclines
of UK Postcodes from point cloud address data. Fortunately I didn't have to do
the entire country, only a couple of million addresses, unfortunately it had
to work on a machine running Windows 3.1 with only 4MiB of RAM....

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alexholehouse
Quick mash up adding plots for population density, % renter property and %
owners (this took about 2 minutes - I was just intrigued how they all
compared, which seemed especially relevant given the most recent XKCD).

<http://www.holehouse.org/other_content/sanfran.jpeg>

Source of maps: <http://maps.webfoot.com/demos/demographics/>

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philsnow
It took me a while to remember that the Northwest side of Alameda is the naval
base, and that's why it shows as white on both "occupied by renter" and
"occupied by owner" maps.

The "occupied by renter" map confirms a lot about what I think about SF real
estate, thanks

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rachelbythebay
So Santa Clara and most of San Jose don't exist?

You can even see where it cuts off. See that little burnt orange stub at
bottom center which sticks out into a sea of white? That's Central at
Lawrence, where the SV/SC border goes nutty due to some annexing wars back in
the '60s.

To answer the question posted in the post, no, I cannot find my zip or those
of my friends, either.

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joshAg
I can't believe this didn't at least include cupertino, let alone the rest of
the san jose suburbs.

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isalmon
Nice data, but nearly impossible to understand. It would be nice to put at
least a couple of big cities (Palo Alto, Fremont, etc) on the map, so that you
could understand where's what.

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dredmorbius
Download the raw data and query to your liking.

Under Debian, US Census TIGER files are available as dictionary files. You can
use this to identify specific areas as you wish.

My analysis showed that the most expensive top several ZIP codes were SF
Financial district, Stanford, SOMA, Marina, and Pacific Heights neighborhoods,
as well as Atherton. I suspect the data may skew high, though it would help to
have a distribution within each ZIP code as well (SD, median, quartiles,
5th/95th percentiles).

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johnwatson11218
Does anyone know if any of the big real estate sites do this as a feature? It
seems like zillow used to have this feature but they switched to a different
map provider and could no longer offer it. I recently read a book about making
money in real estate and the author suggested that you produce a heat map like
this (by hand) for the area that you are interested in investing in.

I can't understand why this sort of thing isn't more commonplace. I would like
to be able to create animated maps that show the prices over time. Or add in
height to show the crime rate over time etc.

It seems like real estate is one of those industries with a strong lobby that
has been able to resist having its information become a commodity. When I
bought my condo I thought the MLS was such a joke.

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tyang
Great post. Very interesting.

One suggestion: please further improve your startup's domain expertise w/r/t
Manhattan (I don't know enough about the Bay Area).

Nobody I know in Manhattan - and I lived there over 15 years - thinks of South
Street Seaport the way you describe it:

"The cobblestone streets combined with the low-density feel of the area give
it a historical vibe that is second-to-none in the borough."

There are cobble-stone streets with low density and a historical feel in
Tribeca, which - price aside - virtually all Manhattanites would consider
significantly more desirable to live in than South Street Seaport.

South Street Seaport is a weird area to live. Very touristy. Far walk to most
jobs on Wall St. Far from subways. Not that residential and very windy, since
it is on the edge of the city.

I had one friend who lived in that area, on Cliff Street.

Everyone else was everywhere else.

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jrockway
Sounds like typical real estate "enhanced truths" to me:

cobblestone streets: technically true

low density: nobody else wants to live here

historical vibe: the cobblestone streets make it look old

"It's a shithole for tourists in the middle of nowhere whose streets have been
neglected by maintenance crews for decades," just doesn't sell apartments.

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dmpatierno
Permalink: [http://kwelia.tumblr.com/post/36569269722/bay-area-rental-
pr...](http://kwelia.tumblr.com/post/36569269722/bay-area-rental-price-
heatmap-by-zip-code)

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malandrew
I wish the heatmap scale went beyond $3 per square foot.

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dangrover
Price is only part of the story. Because of rent control laws in SF, prices
aren't the signals of demand/scarcity they normally are. Showings for average
apartments (in older buildings) in SF often have dozens of qualified
applicants showing up, making them crapshoots.

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tlrobinson
I thought rent control only applied to existing tenants, and landlords could
charge whatever they like for new tenants?

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usaar333
That's correct. Not sure what Grandparent is referring to; prices are only
artificially lowered for sublets.

(Rent control obviously causes artificial scarcity, but the pricing info is
correct for what a place is likely to cost you in a given area)

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mmanfrin
It's surprising that Orinda/Lafayette are comparatively cheap now. They've
been historically expensive places to live, they've each got good Bart
stations, easy access, safety, and access to good food. But, people seem to
ignore Lamorinda when looking for a place.

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rdl
I thought they were cheap per square foot because the houses are so huge.

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dredmorbius
There is that.

$/sqft factored by apartment size results in a greater uniformity of rental
pricing than would be immediately apparent. With few exceptions, the higher-
cost areas will have smaller apartments generally catering to singles /
childless couples, while families are driven to more to the periphery.
Atherton and Stanford would be notable exceptions, as both include sizeable
parcels (though how many of these are available as rentals is another
question).

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JVIDEL
I remember someone telling me that certain areas around/near Palo Alto were
considerably cheaper, yet all I see is red/dark-red.

Was that BS or is this map wrong?

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tlrobinson
Parts of East Palo Alto are cheaper (but not necessarily somewhere you'd want
to live...) but this is broken down by zip code, which isn't granular enough
to show major differences (though you can see the Palo Alto area is very dark
red compared to everything around it.

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JVIDEL
Is it that bad? I remember someone that lived there said the place had changed
a lot.

Still if it's that bad then it should be cheaper too, weird how it doesn't
shows on that map.

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tlrobinson
I haven't lived there, but people I know who do seem to report hearing
gunshots somewhat regularly.

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DesaiAshu
Can you normalize this by sqft? Size of rentals available likely skews this
data, as rdl points out, bigger houses are typically cheaper per sqft.

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sardonicbryan
Nice data, thanks for putting it together. Would be really cool if there was a
link to an enlarged version of the table as well.

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stathack
done.

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diziet
It would be even cooler if the enlarged version of the table was readable
without squinting!

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stathack
added downloadable .xls link

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jjm
Do you have Philly data?

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slykat
Any idea on where this data is from?

