Cool Map: The Age Of Every Building In Los Angeles County

If you've ever wanted to see how Los Angeles County grew, a new and colorful interactive map gives you an amazing bird's eye view of how the region has developed.

The open source project—known as built:LA— allows you to progressively see where and when buildings were built across the county over each decade from 1890 to 2008. By clicking on each decade on the map's timeline, you'll add the structures built in that decade to the map with a distinct, corresponding color. (Just a warning: the site itself can be slow to load on older computers.) The colorful layers begin with a light turquoise representing pre-1910 construction, followed by increasingly darker blues showing development for successive decades. The color shifts to purple for construction during the 1950s, and then transitions to increasingly lighter pinks for the following decades until orange comes to represent post-2000 construction.

You can double click to zoom in and hover over specific buildings to see exactly when they were built. And if you click the rainbow stopwatch button, you can watch a timelapse of construction over the century, which comes to a grand total of 2.9 million buildings.

The project was created by L.A. designer Omar Ureta and was inspired by another cool map of Portland. Ureta developed built:LA using the open source software Mapbox Studio and with support from the Maptime cartography learning resource. The data used for the map was made available by the Los Angeles County Assessor's office and the LA County GIS Data Portal.

The map offers a mesmerizing look at how cities and neighborhoods across the county have evolved. From increasingly dense layers developing around urban areas, to the more recently developed suburbs, the map is an incredible visual representation of the city. Watch as construction radiates out of downtown L.A. as the decades progress. Or see Malibu go from mostly a spattering of a few buildings to a thick, Jackson Pollack-splatter of colors.

Since the map is an open source project, it will be interesting to see if others develop the data further or use it for other purposes beyond the cool resource that it is already. The map could offer more insight into historical development trends, the ebbs and flows of urbanization and suburbanization, or fluctuating demographics across the county. Seeing the decades of construction also calls to mind how each successive generation of buildings were only built with the knowledge of earthquake preparedness of the time. And while there has certainly been a great deal of retrofitting done over the years, the map could prove useful for determining which areas and buildings might need additional work.

To give an idea of how the map works, the images below show how an area like Santa Monica developed over the last century. As you move through the maps timeline you'll see only sparse patches of development over the decades, beginning with construction from before 1910. Then as the decades of the first half of the 20th century are layered on, you'll see sporadic development, followed by a significant post-WWII boom of construction. Then once again you'll see development slowing down as the timeline reaches the most recent decades and the area becomes more densely packed.