
What housing “filtering” can and can’t do - jseliger
http://cityobservatory.org/what-filtering-can-and-cant-do/
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dbcurtis
In the case of the Bay Area, where are these new homes for high income buyers
supposed to go? There isn't a whole lot of green field space left to develop
into new, high-end, homes, so that the old homes can filter down.

Silicon Valley, by-and-large, has always zoned for lots of cheap office space
to keep light industrial rents cheap, in order to create jobs and reap the
resulting tax revenue. But it has created an imbalance. Really, if you believe
the thesis of this article, the only solution is to declare Sili Valley (and
the peninsula) "full", or maybe even overflowing. Then rezone some industrial
areas, bulldoze them, and build McMansions. Oh wait, industrial rents will go
up and companies will move out or start elsewhere. It is hard to have it both
ways.

~~~
eru
The solution is, of course, to build higher.

Eg even the plentiful office zoning could become even more plentiful by
building higher.

The new homes for high income buyers could come as part of a tower where there
was only a single home earlier.

Density, not McMansions. Rich people, by and large, seem happy enough to live
in `luxury condos' stacked on top of each other. (Or at least enough rich
people are happy to stack to drive demand.)

~~~
mjevans
//Lots// (flood the market with) of luxury condos and apartments and hotels
(for long, medium, and short duration living).

Extensive design validation _, solid construction, not cutting corners to
badly, generally actually build them to last.

_ Plan for maintenance to happen during the building's lifetime.

* Have a 'car/dog wash' area in...

* A parking garage with room to actually park cars for families.

* Actually acoustically isolate rooms (even within the same unit) for privacy.

* Design ventilation paths that route 'waste' air away from /all/ residence windows.

* If you aren't going to hard-ban smokers from occupying residence within the building, make sure that there are designated smoking areas on each floor. (A scrubbed exhaust room).

~~~
eru
That looks like a sketch of a decent business plan. I hope you didn't mean it
as a suggestion for legislation?

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twelvechairs
The real solution for SF of course is that anything within walking distance of
shops should be built at > 20 storeys (or so). And 60% of the increase of
value derived from this should be captured by government to build public
transport, improve streets and parks, etc. to handle the increased density.

~~~
ceras
>20 stories is what a lot of SF residents fear from new construction.
"Manhattanization" was a big fear there.

As a political compromise, consider low-rise (~5-7 story) buildings. This is
what most of Paris and some of the trendiest Manhattan neighborhoods (West
Village, East Village) have, and it feels nothing like what people picture
when they think of densities at 80k+ people per sq. mile.

I agree mid- and high-rise buildings are best for transit and commercial hubs,
but low-rise in all other walkable areas is sufficient to make a huge
difference in SF with less dramatic change in character, sunlight, etc--the
usual NIMBY concerns.

~~~
stale2002
What if they picked one small, area, perhaps somewhere in SoMA, and built all
the skyscrapers there and not anywhere else? That way the buildings are all
centralized and nobody gets gentrified.

~~~
ceras
Sure, I agree it'd be great to pick a hub and fill it with high-rise
buildings. But I'd advocate a multi-pronged approach; high-rises at hubs, low-
and mid-rises elsewhere. Consider the following:

(1) Skyscrapers are very expensive per livable sq. ft. and take long to build.
Low-rises are comparable to single-family homes, so they're lower-risk for
developers, come about faster, and have a lower minimum rent price (in the
wonderful event SF builds enough housing for rents to go down).

(2) If you neglect the rest of the city and create a sharp density cliff,
transit patterns will be wonky. SF is in an odd in-between stage regarding
public transit, and creating a transit-oriented dense central neighborhood
hurts commutes from other semi-car-based neighborhoods: they should be denser
to justify an increase in buses and trains needed by the city.

(3) In a medium-density city like SF, low-rise apartments would make a huge
difference in supply. Consider the fact that the NYC neighborhood East
Village, comprised mostly of 3-6 story low-rises, is (IIRC) the 2nd densest
residential neighborhood after a part of the Upper East Side, pushing over
100k per sq. mile. Because this avoids the problems of high-rises[1] (e.g.
blocked sunlight, like Manhattan's FiDI), it's not nearly as unattractive to
NIMBYs. The few I've met hate skyscrapers, not low-rises.

I think HN might have a skewed perception of what levels of density correspond
to different building heights, and what those buildings cost (in time and
money). You don't really see huge swaths of residential high-rises in
Manhattan most anywhere. That's due to both quality of life and cost
reasons[2]. SF doesn't need to become Hong Kong anytime soon--there's not
_that_ much demand--so it's worth considering other options for the sake of
political tractability.

[1]
[http://images25.blocksy.com/L_2027825/122330054/original.jpe...](http://images25.blocksy.com/L_2027825/122330054/original.jpeg)

[2] You could argue that in the past 10 years, Manhattan has had an increased
need for more high-rises. But because of cost and the cliff reason mentioned
above, it turns out a big part of the cost pressure in NYC has come from an
inability to build low- and mid-rise buildings in Queens (which has comparable
density to SF).

~~~
twelvechairs
These comparisons of midrise to highrise are common but not accurate. What you
miss is (1) nobodys going to build the quality of east village or european
cities (2) similarly high rises are much better now than the doom and gloom of
the 60s housing estates (3) density comparisons (jane jacobs) were built on
the above models where towers had masses of unusable apace around them. In
reality of course towers allow greater density. (4) east village and europe
dont allow parkig which is a necessity in most of SF outside centres worthy of
greater density anyway (try adding 100 cars and driveway entries to your
photos) (5) absolutely there is hk levels of demand built up - it will take a
lot of towers in sf to dent the housing prices. Let me assure you - developers
would well prefer to build high rise than low rise. (6) For a comparable
density towers will actualy provide more evenly shared sunlight than a street
wall approach. (7) increased infrastructure requirementts for density are far
easier to provided in small dense areas than spread across a city

Vancouver is a good example of a city successfully adopting towers as a
typology (as well as the obvious asian examples). You wont find something
comparable with midrise as its not adoptable at the same scale for the reasons
above.

~~~
ceras
Sounds like we have different philosophies on dealing with political hurdles
and managing cars as SF gets denser, so I won't further my argument.

But I'm curious if you have sources for claims (1), (5), and (6), since they
don't line up with any knowledge I have. And I really like this topic so I'd
love to learn more :)

And just some FYIs you probably already know but just making sure:

* #2/#3, high-rises in the vast majority of non-NYCHA Manhattan aren't the (horrific) towers-in-the-park style you're referring to. I'd forgotten about those!

* #4, East Village does have parking garages.

* Asian cities vary so much in planning that both you and I can probably find dozens of examples of what we're referring to :) (I'm partial to Tokyo and Taipei myself.)

~~~
twelvechairs
I probably wrote that a little quickly. To clarify

(1-3) the broader issue is to ensure an even comparison. Typical debates
around this issue show very nice historic examples of low-rise apartments and
at best mediocre high rise. Originally the density comparisons of jane jacobs
who this argument derives from were arguing (very rightly) for the retention
of heritage areas like grenwich village against turning into terrible 60s
estates. However when comparing new with new and in todays context the result
is quite different. In general terms the quality of new build high rise tends
to be better than new build low rise and the streets for new build low rise
dont look much like your photo (though i wish they could)

(4) im all for reducing parking. But apart from a few places (which should
focus on higher densities imo) SF is not approaching grenwich village levels
of walkability and will need more cars.

(5) not sure which part you disagree with. Any developer (big enough to be
able) will tell you theyd rather build high rise. Comparative hosuing prices
to other cities show that there ia huge pent up demand in SF. In hong kong it
started from the other direction - huge amounts of public housing were built
to ensure employers didnt have to pay workers too much.

(6) 'perimeter-blocks' over a few storeys tend to strongly overshadow low
levels and streets while large upper storeys get good sun all the time. Towers
(or rather slender, well separated towers - like vancouver) have shadows which
move around more and distribute the overahadowing more

~~~
ceras
Thanks for the response!

I'm not familiar with Vancouver -- is this what you're describing?
[https://www.google.com/maps/@49.2821477,-123.1245358,3a,75y,...](https://www.google.com/maps/@49.2821477,-123.1245358,3a,75y,273.81h,118.78t/data=!3m6!1e1!3m4!1sjS1C9OGjlNdu53U9y0hhVw!2e0!7i13312!8i6656)

If so I think we largely agree on SF's ideal future, and differ only in how to
manage the politics and our understanding of the extent to which low- and mid-
rise development would benefit SF.

~~~
twelvechairs
Yes that link is a good example. Obviously some parts are less than ideal
architecturally but the form works for the density.

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nedwin
Something I suspected was the case but hadn't heard the term - or seen any
research on.

In SF the battle is over what will happen in the next 5 to 10 years. In that
context it is politically dangerous to support market rate "luxury" housing.
On a longer timeline this is the only thing that will make a serious dent.

Instead they are pushing for 25% of all developments to be affordable housing,
which will retard the whole market and worsen the problem.

~~~
cassieramen
As long as the absolute number of units in that 75% is large enough, it can
still successfully kick start this filtering process.

Fascinating to see actual studies supporting what the free market is already
pushing for, more luxury housing.

~~~
nedwin
More what I was trying to say is that we're focused on short term gains in
affordable housing (the 25%) instead of maintaining our current 12% and
focusing on total volume of new housing - whether it's luxury or not.

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jmspring
The discussion on "if SF (or wherever) didn't have X, we could..." is amusing.
Communities have building regulations for a reason. Despite all the towers
going in in SF around SOMA/etc., you can still venture out to the pan handle,
the haight, etc. and find houses and neighborhoods that aren't high rises.

Here is Santa Cruz, we have progressives that tell us that we must accommodate
every tom, dick, harry, and jane that wants to live here whether or not they
can afford to do so. Bullshit.

Companies building and hoping to scale in an area need to take the cost of
living, availability of housing, and how that impacts attracting talent into
consideration. They shouldn't suddenly demand that blocks of 5 story buildings
be replaced with 20+ story buildings.

As a bay area native, what people desiring to live in SF and what they have to
pay amuses me. Yes, there is a direct impact on job growth and housing demand,
but rather than insisting that a community change and build such housing,
maybe the businesses wanting to grow, expand, and hire in said city should
fund the development of said housing -- even if it is outside the location of
the office. We already have "corporate buses", why not bring back company
towns and corporate housing?

Or, maybe, rather than requiring people on-site full time, think about
fostering distributed teams.

It's amazing how many companies refuse to even allow a modicum of "work at
home" in this day and age. Any engineer is likely to get contacted by
recruiters from some of the big bay area companies. Shuttle buses are better
than driving solo, but you are still sitting going from point A to point B for
45-60min each way, plus your work day.

~~~
techdragon
In most functional urban centres there is a balance between commercial and
residential tenancy which leads to a "virtuous cycle" where by the growth of
one supports the growth of the other, both are allowed to grow and they both
contribute to the revenue of the region though appropriate municipal/state
government systems such as taxes and fees for essential services.

SF got all kinds of broken by trying to have one without the other... How
would increasing the burden on commercial residents help the situation in any
way other than reducing demand by driving them away?

Remote work is a possibility I think it's more of a long term cultural shift
that is unlikely to solve the current problems without resorting to
regulations enforcing remote work. Regulations which would be shifting the
burden to commercial residents and relevant that would just be

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porterde
London just "filters" lower incomes out completely...

