It's amazing how little has changed in recent years in LA. The massive downzoning of the 1980s had its effect: prevent efficient land use, and channel money into the hands of landlords and homeowners from all newcomers.

LA is a ridiculously unaffordable place to live, not because it's nice, but because of an artificial shortage of built space, due to a monopoly on the permission to build.

>The massive downzoning of the 1980s...

To put numbers to this for those who aren't aware, LA was zoned for roughly 10 million people in the 1960s and by the 1980s it was zoned for roughly 4 million. It's part of the reason the city has had population growth slow to a crawl. It was decided some 40 plus years ago that LA should stay under 4 million people, so it has even til today. But the number of people who want to live in LA is constantly growing, so housing prices continue to rise and as a result lower income people are slowly but surely being pushed out of their homes and out of the city entirely.

Same story in San Francisco of course, and the rest of the US pretty much aside from a few cities in recent years.

At least we have parking lots. Ah, so many parking lots

There's still Houston but that's it as far as I know.

Interesting, I did not know that. Sure helped create the massive urban sprawl that LA is today, I mean it's basically one city all the way to San Bernardino, almost 100 km to the east.

My impression of LA when I got there was that I would never live there, even in the nicest spots. Which confirms my intuition that the richest have no taste.

Also it’s an American city made for cars so it doesn’t help me to like it.

And don’t forget prop 13, there’s negative incentive for property to change hands and develop.

Do people really think that if we revoked Prop 13 that other taxes would go down with the new money from property taxes?

Or do we think that property taxes would go up while other taxes stay put?

This feels like the argument at play when people criticize Prop 13. Not saying it’s good but California hasn’t ever cut taxes meaningfully and I’m not convinced raising property taxes would solve anything. California would still be expensive to live in.

Multiple good things would happen without prop 13:

People would move more instead of being locked in to a low effective property tax.

The tax burden would be much fairer: instead of the police and schools being funded by newcomers, everyone would be contributing their fair share to fund the city, instead of the longest tenure residents mooching off the rest of us.

Unproductive use of land would be discouraged. If a tract became highly desirable, it would be expensive to let it sit in an unproductive form

Cities could raise taxes as high as their residents wanted them to be, instead of being limited by the opinions of non-residents. Some people want to have better funded police and schools, and local government would actually be allowed to deliver that. Citizens who didnt want to live in expensive cities could vote with their feet to cheaper towns.

Under Proposition 19, some people can still move without penalty, as long as they're over age 55, and move to a new property located in California.

https://www.ocassessor.gov/tax-saving-programs/savings-senio...

I've never heard anybody say anything like that when criticizing prop 13. It usually has more to do with housing prices and the fact that 2 people with the same home value should pay the same in property taxes. If you wanted to create a hereditary landed gentry, it would be hard to come up with a better policy to achieve that than prop 13.

To keep tax revenue equal, property taxes for those who purchased recently would go down, and property taxes for those who’d purchased in the past would go up.

The housing market would become more liquid because people would move out of homes if their values rose too much and they could no longer afford the taxes. This would be a shock initially, but over time it would just be seen as part of life like it is in other areas: mostly, empty nesters would downsize to a cheaper, smaller house with lower taxes. Gentrification might be more problematic though.

In practice, probably some phased rebalancing would have to happen to avoid the sudden economic shock, but, politics notwithstanding, it’s not crazy to suggest it could be done and that the end state might be overall ‘better’ for most people. The end state would be how property taxes work almost everywhere else.

Prop 13 massively distorts the real estate market and creates some strong incentives for home owners. Those distortions and incentives would go away regardless of whether abolishing Prop 13 led to a net increase or decrease in total taxes.

It would increase liquidity in the housing market.

Yes, your property tax is high ($17k) because of prop 13 - you are effectively subsidizing others who have sat on their residential and commercial property for 20-30+ years who are paying 25-50% of what you pay for any similar property in the same calendar year!

Your property tax goes up by 2% of your , guessing (relatively recent?) purchase price, and theirs goes up 2% of a much smaller base due to prop 13.

They have no incentive to move, downgrade. And they often use trusts to pass this tax base down to their kids. It’s feels like icky European feudalism.

Again i’m emphasizing that this goes for both residential and commercial buildings.

I agree with everything you’ve said, but one clarification: you don’t even need a trust to pass the tax break down to your kid when you die. Sure, a trust can streamline that process, but it’s not required. At least everyone lucky enough to inherit benefits, not just those whose parents had the foresight (and the means) to create a trust.

> It’s feels like icky European feudalism.

Pairs nicely with the permitting processes that basically boil down to "thou shalt pay the guild"

> Do you own your home? Here in Ca?

Yes and yes.

And I pay 10K less a year than my neighbor for the same value house. And I pay 10K more a year than my other neighbor.

I get a huge advantage from Prop 13, but I still think it needs to get replaced with a much fairer system.

That is close to the average rate of inflation, though. Doesn't seem unreasonable to me.

They go up much more than 2% in literally every other state, California is the cheapest place to own property for >10 years.

You can argue against property taxes entirely, but Prop 13 definitely means that families, businesses, and all property owners work very hard to never sell, never reassess, and never change their tax rate.

I’m not sure why people are downvoting (without commenting), but I agree.

The main selling point of prop13 was a real problem: rapidly increasing values were driving up taxes so fast that long time residents (of modest means) were being forced out.

I don’t think it’s entirely unreasonable to have some policy that attempts to protect people living in their primary residence from rapid tax increases they can’t afford.

It really isn't. You could—and we did!—solve that problem by letting people defer property tax payments or borrow against their equity. California literally has a property tax postponment program for seniors. If we just wanted to keep people from being pushed out of their homes by rising house prices, we'd just expand that program.

The point of Prop 13 is to let people have their cake and eat it too: you get to keep the equity you gain from increased housing prices, but not pay the property tax that comes with them.

With postponement you then can get the opposite problem of people getting stuck in their houses because if they sold they would have a huge deferred tax.

The approach in Washington works well. There is a senior property tax exemption based on age and disposable income. To qualify in King County (where Seattle is) in 2027 you need to be 61+ and have a household disposable income under $101k.

That gets you (1) a freeze on the assessed value for taxes equal to the current assessed value, and (2) an exemption from the statewide school tax and from "excess levies" (basically city and county levies that are voted on).

If income is under between $76k and $89k they also exclude from tax 45% of your assessed value or $70k, whichever is larger, but not more than $200k.

If income is below $76k they exclude 80% of your assessed value or $80k, which is larger.

The income levels are based on median county household income so vary from county to county.

Disposable income is basically everything that goes into AGI plus a list of other things (like any Social Security that is not already in AGI). There are also a bunch of deductions, mostly medical including Medicare premiums, with a $7500 deduction you can elect to take instead of taking any of those specific deduction. Income includes all adults living in the house.

In my county the levies that are not "excess levies" are county roads, sheriff, conservation, mental health, veterans relief, fire district stuff, public utility district stuff, and regional library. The "excess levies" are a couple of school district levies. Overall the excess levies are about 28% of the property taxes in my county. The statewide school levy that is exempt is another 10%, so the bottom line is that the property tax rate for seniors under the income limit is about 60% of the non-senior rate.

So people were getting so wealthy that they couldn't pay the property tax on their wealth. Yes. The problem is, if you let them decide to tax other people instead of themselves for the spending they themselves approve, they will.

I don’t think you read my comment very carefully

What if I did?

That makes it sound like the increase was due to some inexorable natural force. California's per capita budget is over twice Arizona's, and they're running a huge deficit on top of that. If taxes are too high, cut taxes. If that means you need to cut spending, cut spending. But don't play "hey, let's tax the other guy!" games and expect that to work.

A lot of this also comes down to prohibiting growth. In Seattle, every time we build a new building, everyone else's property tax payments decrease. High growth years lead to lower bills. The same would work in California, they just don't build much of anything because they've made it nearly impossible to.

You're not wrong, but the irony of positioning Seattle as having good zoning policies is almost unbearable.

Prop13 was a big tax cut. The people behind it were minimal government conservative libertarians.

And the state did slash spending in the years following. In particular funding for the university system was hit very hard.

They did not slash spending. At most the rate of increase slowed down for a year or so before continuing to rise at an even faster rate.

https://dof.ca.gov/about-us/history/state-budgets/

This is a solved problem.

Let people defer increases until their house is sold. This what many states do.

It’s seems insane that we “protect” people whose property taxes are going up because their home is getting so valuable

I was just down there and saw multiple massive development projects going on. Like huge new neighborhoods.

Of course they aren’t in LA proper. But it seems like people that want to live in SoCal want the suburbs. You talk like LA is this artificially small place except that it’s more like a neighborhood in the middle of sprawl at an almost unimaginable scale.

Not saying any of this is good. In fact it’s terrible. Personally I feel like the entire LA metro area is about as close as you can get to a real paradise lost on earth. Maybe one of the most naturally beautiful places on the planet, bulldozed over for a maze of 6 lane uncrossable suburban streets and cookie cutter McMansions.

It only seems like that because every other type of housing is literally banned.

If apartments, even small buildings, were legal in LA, they'd be building them everywhere and they'd immediately fill up.

The Mayor, Karen Bass, accidentally screwed up and made affordable possible to build, as in allowing it to get through the gauntlet of approvals. This resulted in a massive amount of extremely costly affordable housing to get built, merely because the approval couldn't be stopped arbitrarily:

https://www.pacificresearch.org/la-mayor-slowly-dismantles-h...

Ift that sort of project approval was opened up to not only affordable housing, but also for-profit housing, there would be a massive shift in the type of new housing in the area.

I have a dumb question. What is the eventual of efficient land use? Say we bulldoze a bunch of single family homes and get 10x as dense. Now we have 10x as many people per square kilometer. Is that an efficient use of land? Will there be someone saying at 10x population density that it's an inefficient use of space? If yes, what would they propose instead?

Why are you acting like there isn't a definition of inefficient. I think "underutilized" is a pretty good definition.

The fact that every single person has a small private park in their front and backyards that's enjoyed maybe a couple hours per day at most is pretty wasteful - if it was shared the utilization would go way up and space used would be way down. Same goes for all the parking lots needed to facilitate car traffic - if we used more efficient/shared options like buses or trams then the parking lots that sit empty most of the day could be replaced with more businesses or houses that allow people to live closer to the services that they need every day.

Meanwhile, we have big bottlenecks in our city downtowns where all the density is packed. Spread that out and things get a lot more efficient - your commute probably goes down too because you can live closer to work. Suburbs don't work without a productive city near them - otherwise they're just rural areas.

There's a really great way to think about this that doesn't get enough attention: land rents.

Some plots of land are very valuable due to their location, what you can access, etc. It's pretty straightforward to find out what the monthly cost of land is in any area, either from simple regressions on property values, or empty lot sales, etc.

When the land rent starts to excessively exceed average income of number of households allowed to live on that plot of land, that's pretty inefficient.

Owning land is society letting you say to other people: you're not allowed here. When we restrict land us so that people can not figure out their best use of it, eg 4 families building townhouses together, we start to restrict access to opportunity and basic economic freedom.

this is the same fallacy of saying there's no point getting a 10x faster server because you'll just have 10x more load and your site will still be slow.

If you're really interested: as density increases, population growth decreases. High density places become a sink for populations from elsewhere. You end up reaching a regional equilibrium, where some of the lowest density places start emptying out entirely. Japan is a great example of this, small towns there disappear regularly, as Tokyo grows. Suburban life around Tokyo remains very stable as the center increases and edges decrease.

Yes, dense cities are more efficient in every way compared to sprawl. Can you articulate what is confusing about this?

NYC has had so much downzoning too. The icon of the city, the Empire State Building, now has a floor area ratio about double what’s permitted in that district. Many historical buildings, just like ESB, simply could not have been built today under current zoning regulation.

The city’s original 1916 zoning regulation permitted a hypothetical maximum population of 55 million; after WWII the new zoning regulations essentially limited hypothetical maximum population to a little more than 10 million if everything is fully developed. Recent initiatives like City of Yes did too little to reverse the trend.

NYC zoning is less limiting than LA, but still extremely limiting.

By what measure are you saying they've taken the opposite approach? It seems to me their approach has been nearly identical, just a little less restrictive.

Everything has a gigantic depends* on it when it comes to RE. People want to find one reason why things are bad, but it is always a big bag of mixed things.

When I was in Vancouver, people kept saying if we got rid of rent control, houses will be built, rent will come down. But houses are expensive to build, and they need to make money asap in the “exit economy”. They won’t come up easily, unless they make it cheap to build, which isn’t happening. Rents just started coming down, but so far insignificant amount (I just checked, a place I paid $2500 for in 2019, is going for $3300 after the decrease!), and demand curbing had more influence on it. Personally, I think we shouldn’t force people to move to a different area because rents skyrocketed. I’m all in support of getting paid out though.

People look at Tokyo, and talk about “less-zoned build whatever, and no rent control, thus more or less affordable”. Which also depends*. YoY rents are going up by 10-15% right now, even more in some areas. It’s unreasonable for a good chunk of residents. Speculation is big influx of money from China. But you can actually challenge the rent increase in a good chunk of cases. So it’s a pseudo-rent control.

I’m not saying something is right or wrong, just saying everything has multiple layers of problems.

It's simpler than you're implying. Vancouver, like most cities, has dramatically limited what land you can build on. More than half the city is restricted to nothing larger than individual houses.

Tokyo, similarly, has hit the limit of what they allow to be built under the highest density of their stepped national zoning levels.

Nah, watch this if you have time: https://www.youtube.com/watch?v=kpK5HiCKfgU

At least watch this money shot: https://youtu.be/kpK5HiCKfgU?si=YNQBxsn15NxGdQQ0&t=272 (wait for the video to reveal the construction years)

As Max Fisher puts it: American cities have been frozen in amber.

This is such an amazing video. It collapses about three years of my casual research into housing down into just a few minutes. Thanks for sharing.

There is also a completely unreasonable shortage of water for a much bigger city.

I've lived on the westside of LA for ~20 years, so one secret I like to let people in on: there's no water shortage. There's a literal ocean of it. I can see it right out my window.

And all that it takes to turn seawater into potable freshwater is energy.

We don't have a water problem. We have an energy problem.

For all of LA County, it would take 500–750 MW each year to use seawater for all our freshwater needs.

Or put another, with a single nuclear power plant, we would solve all LA's freshwater needs -- forever.

You don't have an energy problem, you have a political problem. Fresh water is wasted on thirsty plants destined for agriculture (like alfalfa), by rich farmers who inherited water rights put into law ages ago. It's very simple to solve water usage in California, it just requires a governor that has a tiny amount of grit and cuts into their water rights.

It's crazy how to some, building a whole nuclear reactor and dozens of desalination plants seems like a simpler solution than making a couple of very wealthy farmers a bit angry for a while. Capital really is all-powerful in the States, it even holds power in the very minds of its citizens.

It's not only energy though. Desalination takes space, and you have to do something with the salt. Last I saw, to have enough DeSal capacity for all of California, you'd have to replace every beach with DeSal plants to have enough capacity, and then you'd still have a salt problem.

You could put the salt on boats and dump it back much further out in the ocean, but that too takes energy.

Dense, newer housing needs a lot less water. If Los Angeles had densified rather than sprawling into the Inland Empire, etc. overall water usage would be far lower.

As it is, water usage in Los Angeles has had flat water usage for decades, even as its population grew by over a million people.

By downzoning so much, Los Angeles got the worst of all worlds: higher water usage, unaffordable housing, and unbelievably bad traffic because everybody has to drive such massive distances to the job centers.

Downzoning is an environmental disaster compared to the alternative, like allowing factories to dump their pollution into rivers type of disaster.

CA has droughts, but not water shortages. Most of the water goes to highly inefficient and low value farming.

Sure, but without that farming, how would we get our almond milk lattes?

This is more like the construction date of buildings that have survived. Some early neighborhoods (like palms) have been completely replaced building by building so they really appear as dark here when they weren't. It had a downtown in the 1890s but all those buildings are gone. https://en.wikipedia.org/wiki/Palms,_Los_Angeles#/media/File...

it's basically this data: https://portal.assessor.lacounty.gov/ through this portal https://data.lacity.org/

Exactly this -- This is more like the construction date of buildings that have survived. Everything demolished, burned, or replaced is invisible.

Probably should put that front and center.

Yes. The description is quite misleading. The fact that it is simply an overlay of the current map is also misleading. Looking at the west side, it completely skips the canals period of Venice. Marina Del Rey evolved considerably into its current form. Ballona creek was only dammed in the 30s. Etc.

Also noticeable as the first buildings show up - each one isolated and miles from anyone else? Generally not how human habitation clusters up, even if it was all farms to start.

this is the best resource I know of

https://mil.library.ucsb.edu/ap_indexes/FrameFinder/

It genuinely is much more sporadic then you think. 1 or 2 houses, then empty blocks with streets there, then 1 more, then some building ...

For a modern version, look up california city - modest suburban homes respectably maintained with cars in the driveway surrounded by endless nothing.

I have to presume there's some people that look at this and say "wow, this is perfect".

Los Angeles had the largest public transportation network in the United States until we paved over it[1]. We had over 1,300 miles! You could've gone from Huntington Beach to Downtown and all the way up to Burbank. You can see many of the maps of Los Angeles at the public library[2]. I don't live there anymore, love that place though.

[1] - https://www.pbssocal.org/shows/lost-la/from-rail-to-roads-an...

[2] - https://www.lapl.org/research-guides/maps/maps-los-angeles

My mom (who is 97) has a vivid memory of seeing FDR in 1935 -- the whole extended family took the the Red Car from Compton to downtown to see his motorcade. She remembered the electric trams worked really well, especially for folks without much money.

> worked really well, especially for folks without much money

That's probably part of the reason they got rid of them. You still see that argument used against transit: "it will bring _____ to our part of town".

The trams went away because of cars and buses, not because of racism.

It can be both. Highways didn’t get built for poor folks, but did get built right through many of their neighborhoods.

Fun fact: this is the plot of the movie “Who Framed Roger Rabbit”

It’s making a comeback

Bit misleading since it only shows properties still standing, seemingly. So the older periods look extremely empty.

This is one of those 'hey, I can vibe code this in a weekend' projects. Just look at how the AI decided to the entire map in dark mode, making it nearly impossible to tell the ocean and the land apart.

Yes, great point. What was torn down, burned, destroyed, etc. along the way isn't here. This is the surviving city, not the city as it was.

As others have pointed out, this is more about the age of existing buildings than the construction of the city, but it's pretty neat.

About ten years ago when we were working on Mapbox GL, I did a mobile-native viz like this to show off the vector tile tech. The blog post is still up (thankfully) which has a good bit of info on the data processing pipeline as well, ranging from Shapefile to GeoJSON to vector tiles on the backend to Swift on the frontend:

https://medium.com/mapbox/visualizing-an-entire-citys-buildi...

I always loved mirroring a phone to a large TV and showing this off at 60FPS. It was such fun tech to work on.

A complementary view of one point in time is the LA Noire video game's attempt to recreate a (condensed and simplified) 1940s LA environment, with 3D architecture, cars, and ongoing expansion.

https://www.youtube.com/watch?v=OGPh2AcmG2A

The storytelling atmosphere is somber film-noire-ish, but there's simultaneously a feeling of national prosperity and potential for many (with notable unjust exceptions), like I think fewer people feel in more recent decades.

Would also be interesting to try to convey that kind of change over time, in an immersive way.

Did not think of that - yes that is a really interesting idea. Totally different way with interacting with data. I'm going to ponder that...

Very cool, what ddi you build this with?

Having moved to LA this february, the sprawl is really something I had no true appreciation for until I moved here for real, and tried to run errands across town. It's a gigantic, beautiful, complicated place.

One the experiences for me that never gets old is coming in to LAX (flight path East to West) and the sprawl just goes on forever. The other crazy thing that 60% of the population speak a language other than English at home. So I think it has one of the best options for cuisine in the world, because it's all there (somewhere!)

A family member lives near Pasadena. We asked if they wanted to go to a restaurant near Santa Monica. They sort of scoffed at the idea of going over to the west side unless it was really important.

I think a not insignificant amount of it is literally just pavement too. Absurdly wide roads and parking lots everywhere. It’s a bit of a hellscape really.

All the way to almost San Diego, which is insane

The density at least means you don't have to really run across town for much and can stay within a certain radius for most all your needs and wants. I mean look at the density of costcos alone. Many other metros might have 1 or 2 for the entire area. Then again a lot of other metros you basically can drive end to end in 25 miles.

I'm confused. LA doesn't strike me as dense. How dense can you get with huge areas of single family homes?

LA is the densest major urban area in the country. The MSA isn't dense cause it includes all of Los Angeles County which is half desert and mountains. But the built up area beats Chicago and New York cause it has consistent, medium suburban density, 7400 people per sq mi. The others have dense city, New York City is 29,000 people per sq mi, but the far suburbs drop off.

8200/sqmi on average. Even the single family home areas punch above their weight compared to the rest of the country because lots are mostly only 50ft wide and most all build-able land is put to some sort of use already.

It's a bunch of cats (mid-sized, and generally mid all-around, cities) fighting under a blanket. The history of the place is a reaction against New York, where the city is dense and had a bunch of super tall buildings. LA, as a region, said "well we don't want that and enacted a bunch of building codes to hamstring any single city in the region from potentially being a successful, mature urban center.

Pretty infuriating to visit Barcelona recently and see that there was a perfect example of good urban planning sitting right there for decades that LA could've simply copied. In the long run this region is simply incapable of maintaining its infrastructure with its tax base, even today you can see it starting to collapse.

I did a project recently where I extracted every Los Angeles building permit record for a property and was able to look at the evolution of its infrastructure and tenancy over time by embedding the permit documents into an image-based embedding model. Could be an interesting way to incorporate more granularity of the history of properties over time, although it dramatically increases the scope of data processed.

Interesting idea. Is there a practical way to obtain those permit records at scale?

I had an LLM reverse engineer the API protocol of LADBS and extract the content I wanted. Wether that scales from one property to many (rate limits for one) I don't know, but I didn't encounter anything in the thousands I extracted.

I noticed most of the tall buildings are sixties to eighties. Some more info about that here. https://www.pbssocal.org/shows/artbound/a-brief-history-of-l...

Thank you! Great link!

And here is one that is just fun to watch because of Huell Howser --

Tallest Building | Visiting with Huell Howser https://www.youtube.com/watch?v=5ziEDhCPjOQ

Wikipedia has a nice visualization of the history of LA's tallest buildings.

https://en.wikipedia.org/wiki/List_of_tallest_buildings_in_L...

Interesting visualization. I feel like it's misleading though because the presentation shows only Los Angeles City boundaries, not the area in general. LA City has that strange vertical shaft down the the port so the city could keep the taxes from the port, but the visualization shows the rest of the area as empty, which of course it is not. It also excludes Orange County, Riverside County, and the whole area north, the San Fernando Valley, and those all arguably are just as important to the story. In the end, I think the visualization ends up being a net negative in it's current form since it's very misleading

As an Italian I am always amazed when I remember that cities like LA or San Francisco are just 200yo. Here in Italy (but it’s the same for quite any city in Europe) every city can trace its roots back at least two thousand years.

They paved paradise, and put up a parking lot.

Paradise? LA was a big giant horrible underdeveloped wasteland in Spanish/Mexican times which, at the time in 1849, had 1,600 residents. Most of them had a largely pastoral life and life was brutal there.

LA under US rule is the prime example of what industrialized people can do to a place that lacked nearly everything of what it is at this moment: a world-class city.

Objectively, if it had stayed under Mexican rule, it’d resemble Yuma at best or Tecate at worst. I should know, my family lineage goes back to that era to both sides of the border.

One's "underdeveloped wasteland" is someone else's untouched paradise. Particularly someone like Joni Mitchell.

Was it that a big, giant, horrible wasteland because it was undeveloped? That is, was there something bad about it other than being undeveloped? Personally, I love living in the city AND land in its natural state.

Also, GP was quoting a song lyric.

I think the best intro to LA is Cadillac Desert by Marc Reisner (it's really about the entire West and its relationship to water, but I think the first few chapters explain LA better than many other books.)

Funny. It's concrete hell.

It's part of a very popular song from the 70s by Joni Mitchell called "Big Yellow Taxi".

Counting Crows did a cover in 2002.

Is there an alternative if 13 million people want to live somewhere?

Somewhat sadly, the reason a lot of the ancestors of those 13 millions moved there was that they wanted an unpaved paradise.

Unfortunately, humans do not know restraint.

Wow this is inspiring. I would love to see a very similar visualization for Stockholm, Sweden. I think there is a beauty in seeing a summarized history of expansion, and in reality I can't help but think this is a very fast population boom. One I am sure most metro areas would struggle with. Makes a lot of criticism of LA planning in hindsight feel very unfair.

LA county has about the same population as Sweden.

Just started reading Shawn Levy's book, "The Castle on Sunset: Life, Death, Love, Art, and Scandal at Hollywood's Chateau Marmont" which relates the history of the hotel, but I found the history of Hollywood and LA fascinating. Its a huge part of the story of the hotel and development of the areas surrounding the hotel.

Nice! Would be better if it shows the difference between the ocean and other land

Agree, I personally also think dark mode never goes well with a map-based app...

Especially with this sort of map regarding this specific city. For example, Beverly Hills is a separate municipality contained entirely within the borders of Los Angeles. It appears here like an empty black space no different from the ocean, lakes, mountains, and parks also scattered around the city. The styling of this map makes it impossible to tell if an area is truly undeveloped and if so, why. Throw in the way there appears to be arbitrary selection criteria for some buildings outside city limits that make them appear as lone buildings in undeveloped space, and I think it adds up to potentially give people a wrong picture of the area.

Yes, good point. The LA City data was rich, but the other communities have data in other places. I will see what I can do.

Great, I'm sure getting more data for a complete picture of the area is a huge undertaking, but simply switching to the light map that shows the geography more clearly is a big improvement.

Good idea! Let me work on that...

I added LA County data, and checked it against where I group up and where my mother and father grew up. Seems reasonably accurate so far.

Funny, I built the same thing 9 months ago for Denver, CO - nothing too interesting other than 1 subdivision that exploded in growth over 1-2 years in the 70s. A lot of the older areas around Denver built up pretty quickly.

This is super cool. Seems to be quite laggy for me though, when the timeline reached 2026 and stopped, buildings still kept popping in for the next 30 seconds.

Yep, that was my misconfiguration of the CloudFlare cache. Hopefully fixed now.

What is that huge gap near Venice?

To the north is Santa Monica, its own city.

The obvious next step here is to do LA county, since so much sits outside the city limits.

Just added LA County. I spot checked a few places I know, seems to be pretty accurate.

Very cool, but I think it'd be even better if the new buildings popped up rather than faded in.

SF version would be quite boring

Like mould growing in a Petri dish.

Is this actually representing homeless encampments?

wild to see that, reminds me vaguely of the amazing ariel photos by kite of San Francisco after the earthquakes in 1906

* https://en.wikipedia.org/wiki/File:San_Francisco_in_ruin_edi...

early 1900s to early 2000s was a wild and crazy ride for humanity

when I was a teenager I used to run early morning before sunrise and I would never see a car, like maybe once per hour

but these days it's like rush hour at 5am which is frustrating and annoying

and then I realized in perspective that within my own lifetime from teen to 60 the world population has more than DOUBLED, so what I am experiencing makes some sense in that regard (plus technology advancement)

it's amazing

Well done! What an illustration of the amazing spirit of the founders, followed by the glacial movement as we allowed NIMBYs to take control through more and more laws.

Brilliant.

the Wilshire Corridor view is completely wrong, it should be the stretch of tall buildings a bit above Century City in the Century City view.

hey I feel like we should work together on something. I maintain https://www.kaggle.com/datasets/landrecordsus/us-parcel-laye... and https://landstats.com.

Now do Austin?

I joined the county's 2020 lidar building footprints (LARIAC) to the assessor roll, so every one of the 1,129,558 buildings inside the City of LA has a footprint, a height, and a year built for 98% of them. (All public info, but kind of a pain to grab.)

The page extrudes them in 3D and plays the city filling in from 1880 to now. Colors are by decade, or switch to height and fly to downtown. Hover any building for its address, year, height, and footprint. Some things I found: the 1950s, not the 1920s, is the biggest decade still standing; the Valley visibly snaps into existence after the war; and downtown's 150-foot height limit shows up as a hard ceiling until 1957. Zoomed out it draws a 100 m grid because a citywide view can't carry a million polygons, and heights are exaggerated below street level zoom (the corner label says by how much).

Stack: DuckDB spatial for the join, tippecanoe to PMTiles, MapLibre fill-extrusion, all static files on R2 with no server. City of LA only, since the parcel polygons I pulled stop at the city line.

Happy to answer questions about the data or the rendering.

[Just a fun project, no commercial relevance.]

Didn't realize you could zoom in until I saw this. It looks really cool when you zoom in and it replaces the boxes with actual building shapes.

If you want to encourage folks to continue their efforts and really "build something", I think you'd want to ask your questions in a way that shows genuine interest and support, rather than ridiculing and questioning the level of effort involved.

I agree, I'd love to learn where the dada was sourced! I'm also curious why it appears to come in waves, as opposed to each building going up independently (as I would have expected it to in reality). Cool idea! I can see my house from here haha.

The waves are partly real and partly me.

LA genuinely built in bursts. The 1920s and the postwar decade each account for over 230,000 buildings still standing, and the 1930s and 1970s onward are much thinner, so even a perfect per-year animation would surge and pause.

But really it's for performance -- I group buildings into 5-year bins and fade each bin in over its span, rather than popping each building at its exact year.

A per-year filter on a million polygons re-tessellates every visible tile, which was too slow to animate, whereas fading pre-built layers is reasonably fast.

Glad you found your house!

This started as a data puzzle. There is a lot of public data but it's hosted by for-profit companies and the data models don't seem to be coherent (probably lots of good reasons for the data models being the way they are, so no criticism, and it's wonderful they are public.)

So for LA City, they use Socrata (owned by Tyler Technologies -- NYSE: TYL) to host and publish open data. LA City also uses Esri's ArcGIS for geo-based data.

So behind the scenes there is my code that builds a parquet database of * MyLA311 service requests * Permits * Construction Enforcement * Crime * Parcels Id with Polygons * Lidar

So that part was a typical data-munging exercise, and it was fun & interesting to me to learn how public entities try and deal with IT budget cuts and service the community, etc. (For example, 311 requests for homeless issues are transferred to another department, so they all look they are closed immediately, but I never could find the agency data that ultimately resolved that type of request.)

So I have a pile of data that is organized in a way that makes sense to me, but I could not build an interface that I liked.

So I asked Claude to create a fly-over visualization to see what it could do with this data, and it blew my mind.

I'm a life-long coder and I'm old, so it's an interesting experience to see how good these models and coding harnesses are, and how quickly they are improving.

As to what makes this HN worthy? I enjoyed playing with the interface, and there might be more people than just me who love LA (warts and all) and its history and architecture. So it's interesting and I'm not asking for anything in return, so for me that satisfies the "HN Show" criteria.

The deeper question for me right now is what does hacking mean when the coding is done by these systems? It's a different kind of hacking, and its makes things possible that impossible before, but it's a million miles away from 6502 assembly.

It’s great! Agreed don’t feed the trolls.

I’ve helped with a few other zoning visualization projects recently, similar workflow. The only similarity is that each city/jurisdiction makes its data available in a different way. It’s usually accessible but it does mean there’s a lot of work munging the data to a usable format.

Here’s one of the projects: https://github.com/kfarr/zoningviz

Yes, this is incredibly similar to the pipeline I ended up with -- https://github.com/kfarr/zoningviz/blob/main/HOW_IT_WORKS.md

The other thing I learned is that some of the data sets use a destructive insert, so unless someone is doing a data snapshot data elements can be lost. (The vendors charge extra time-series option.)

No need to justify yourself to some bitter, petty, sad troll. Let the upvotes and discussion speak for itself. I love seeing other people's vibe-coded projects come to life. I've re-started a bunch of stalled hobby projects thanks to AI.

> What cool problems did you (not the robot) solve?

Building products has nothing to do with technical problems, just the end result. This is in contrast with things like writing a library or coming up with a new algorithm, or doing research, or even writing a technical blog post, etc.

> or is it just pretty?

People have been sharing "just pretty" things on HN for decades. It might be interesting, thought-provoking, discussion-worthy, or whatever. Even if this wasn't vibe-coded, it wouldn't be some monumental technical achievement. Your point is absolutely moot.

Pretty great day for HN. You can’t just shut off people anymore with „machine did it, not you” as we live in new reality. Comments below make even more sound argument, for data viz we probably don’t need novel problem solving, just people interested to see viz