Urban footprints: some building outline data sources

This is an informational post about where to find building outline data, which I've used a lot in previous GIS projects. It might also be of interest to architects, engineers and anyone interested in urban studies and planning more generally. I like using this kind of data to explore cities as it gives us a good idea of the layout of the urban fabric, as in the example below (New Orleans). The links mainly refer to data from the US, Canada and Great Britain but other parts of the world are covered to various extents by OpenStreetMap.

New Orleans

Let's start big, with OSM... Steve Bernard has produced an excellent video which explains how you can get OpenStreetMap data directly into QGIS very simply - he uses Madrid in the example. The accuracy and coverage varies a great deal across the world, so you need to bear this in mind when downloading and using it - but on the whole it is a fantastic resource. The example below shows Mogadishu, where the coverage is incomplete for buildings but pretty good for the road network. 

© OpenStreetMap contributors

Another useful OSM-related resource with decent global city coverage is CAD Mapper, where you can download areas up to 1km square for free. However, I'm focusing on open data today so will not go into detail on this. The best OSM download source is I think GEOFABRIK (German for 'geo factory), a German GIS consultancy who extract and process OSM data and then make it available for free online. It's really nicely structured and easy to find what you're looking for. Here's the download page for New Zealand, for example - followed by the contents, where you can see the building data on top of a current OSM base map. At time of writing, the zipped shp folder for the whole of New Zealand was 146MB.

The New Zealand GEOFABRIK download page (20 July 2015)

Auckland, NZ - very good building coverage here

The OSM sources are great, since the licence is very generous and you can use the data for just about anything, so long as it's properly cited. However, many towns, cities and counties across the world also provide building footprint or outline data (the terminology varies from place to place) so I've put together a list below of ones I know about. Some of them (e.g. Detroit, NYC) cover land parcels or tax lots so are slightly different but in the main it's just building outlines. I've included visuals for some of the datasets, so you can get an idea of what they look like.

New York City - from the BYTES of the BIG APPLE website you can download the MapPLUTO dataset, for all 5 Boroughs in New York City. Tax lot level rather than building outlines, but it's an extremely rich dataset with loads of useful land use planning variables in it, including 'year built' and number of floors. A little sample of the data are shown below, for the area around Central Park.

A little sample of the data (using Qgis2threejs)

Chicago - the building footprints layer is avaiable in two versions online, one of which says it is deprecated but I've heard from the Chicago GIS team that this isn't the case. It's just that due to limited staff the dataset is only edited when necessary. Also contains a 'year built' and height variable.

San Francisco - another really good city buildings dataset, from SF OpenData. Also lots of useful variables in this dataset, including height. I really like this one.

Dallas - you'll probably get a disclaimer box in a pop-up when you go to download this. I've linked to the general GIS page and the file you want is called Structures (Building Footprints) in the Planimetric Data section - it's about 81MB to download and the unzipped file is well over 100MB.

Atlanta - again, I've linked to the GIS page, this time from the City of Atlanta and you need to download the 'Impervious Buildings' layer. If you're looking to map the sprawl of Atlanta, this won't work as it covers the City area only. Still, a very useful dataset.

Denver - excellent open data from Denver. This dataset covers all permanent structures and buildings for a 152 square mile area of the City and County of Denver. Available in a number of different formats.

Seattle - this dataset was created in 2009 by Pictometry International Corp but is now in the public domain. It is available via the City of Seattle's data website.

Los Angeles - this is a fantastic dataset for the County (not just the City) of Los Angeles, which is the most populous county in the United States (just over 10 million). Made available via the LA County GIS Data Portal. It is a little hefty (581MB) so be careful! In the example below I show all the buildings in LA County but the City of Los Angeles in dark shading, just to emphasise its crazy shape.

Boston - this was created in 2012 and is available via the City of Boston. Contains a number of different fields, including base elevation of the structures, the elevation of the highest point above sea level and fields on building type.

Detroit - like New York, not strictly a buildings outline file but instead a property lot level dataset. Very impressive dataset produced by Data Driven Detroit's Motor City Mapping project. I've used this data a lot in talks and teaching as it's a really good example of its type.

Now some links to further datasets which I know of but haven't used that much...

Washington DC - link is to the download page, but direct link to zip is here (559MB unzipped)

Baltimore - the top link on this page

Philadelphia - via OpenDataPhilly

Massachusetts - buildings for a wide range of towns and cities in the state

Boulder - this is from Boulder County, Colorado. Available in a number of different file formats.

Bloomington, Indiana - one of many smaller cities with excellent geodata

New Orleans - an excellent dataset, not just because of the unusual shape of the city!

Toronto - don't be confused by the '3D Massing' terminology here. Scroll down to the 'Data download' section

Vancouver - doesn't cover the whole city and they were digitised in 1999 but still a useful dataset.

Waterloo - this is from the Region of Waterloo and was up to date as of January 2014.

Hobart, Tasmania - an nice example of building data from Hobart in Australia. Contains a 'year constructed' variable.

Wellington, NZ - can't overlook New Zealand! I think you need to register to download this but it's Creative Commons 3 so still open. 

The list wouldn't be complete without mentioning OS OpenData for Great Britain, provided by Ordnance Survey. A new dataset with detailed buildings became available in March (the OS Open Map - Local) dataset. The building data is a very small part of this collection but one I find very interesting. I've patched together a few cities here to get the ball rolling but you can download your own. There's also a 'tile finder' to help you identify which OS tile you need to cover your area of interest. 

This could save you some time 

I think this just about covers it. Get in touch if you have any other great data sources for building outlines.

WIMD 2014 Shapefiles and Maps

The Welsh Index of Multiple Deprivation 2014 was published on 26 November, using more up to date and improved indicators. The Welsh Government have provided some nice interactive mapping, but James Trimble's version is I think even better. I've done basic interactive versions in the past, but today I just want to share the raw GIS data and a few maps, for anyone who is interested in either looking more closely at their area or doing a bit of spatial analysis themselves. First of all, here are a few basic WIMD maps, clipped to building outlines (click images to enlarge).

I made these in QGIS, using an automated atlas production technique I've described on the blog before. If you are looking to produce some WIMD maps, you might want to try this method. I've also produced some WIMD 2014 maps in standard choropleth format, as you can see below. These are okay in areas which are densely populated but I find them more misleading for larger rural areas where there are not many people.

I know a lot of people across the public sector in particular will be looking closely at the data, so I thought it would be helpful to make the underlying shapefiles publicly available since the data are open. If you click on the link below you'll be taken to a download page via Google Drive. Any questions, then feel free to get in touch.

Download files: WIMD 2014 Shapefiles - for LSOAs and LSOAs clipped to building outlines.

The Urban Fabric of Los Angeles

I've recently become a bit obsessed with looking at the urban fabric of different cities. I've looked at building footprints in English Cities, Scottish Cities, and collected data on a number of US cities, including San Francisco, New York, Chicago and Los Angeles. I've blogged and tweeted about this quite a bit over the past few months and the reason I'm so fascinated by it is that it provides some really interesting visual insights into the spatial structure of cities. I also find it fascinating to make visual comparisons between cities, as in my 'Urban Fabric of English Cities' blog post from October 2014. Now I'm going to look at Los Angeles. I've only been there once but I found it fascinating in so many ways (urban structure; fragmented political, social, racial geography; freeways; congestion; In-N-Out Burger...). Famously, Los Angeles is also the most populous of the 3,144 counties of the United States with a population of just over 10 million. The first image below shows all 3,000,000 or so buildings in LA county - all 4,000 square miles of it (for comparison, London is 607 square miles).

Los Angeles County - population 10 million (higher res)

Anyone who knows anything about American cities will understand that the concept of a 'city' and a 'boundary' is not necessarily as straightforward as it might appear - well, at least not to me as a British person. The City of Los Angeles is a rather odd shape and has a population of about 3.8 million. The image below shows the urban fabric (building footprints) for the City of Los Angeles.

The City of Los Angeles - population 3.8 million (full resolution)

Finally, I've produced a map showing the wider Los Angeles metro area (within Los Angeles County), with the urban footprint of the City of Los Angeles highlighted. The wider metro area extends beyond the boundary of Los Angeles County and has about 13 million people. What's the point of all this? Partly a mapping experiment and partly to illustrate the idiosyncrasies of political and administrative boundaries in urban areas compared to the underlying urban fabric. This is very acutely demonstrated in the case of Los Angeles.

The City of Los Angeles in context (higher res)

If you like these images and want them in higher resolution versions just get in touch via twitter - @undertheraedar or e-mail. I've linked to a high res version for the LA city map.

Data source: Los Angeles County - Countywide Building Outlines

The Urban Fabric of English Cities

[now updated, thanks to @udlondon - scroll to bottom of page]
Inspired by some mapping in the US by Seth Kadish, the availability of new GIS open data, and the fact that I love looking at patterns of urban form, structure and density, I have created a comparative graphic showing the building footprints of nine English cities, with London at the centre (just because it's biggest). I have done this in a very simple way, with all cities mapped at a scale of 1:125,000 in the full size versions (which are massive), plus one small scale bar and a little explanatory text. Here's what it looks like:

The urban fabric of English cities (black/red, medium res)

This graphic does a good job - in my view - of demonstrating the compactness or otherwise of the cities in question. It also illustrates how tightly-bounded some places are and how under-bounded others are. For example, Liverpool is very dense and compact in contrast to Leeds but this really is a boundary effect because the size of the local authorities differs so much. The urban area of 'Liverpool' extends far beyond the boundaries of the local authority area, which is what I show above. I wanted to compare the local authority areas rather than the wider city-region because I wanted to highlight this boundedness issue and compare like with like in terms of formal administrative areas. London is obviously a bit different so I've shown the 33 constituent parts of Greater London.

Take a closer look at the graphic by clicking on the two larger images below - one in white and one in black. They are both just a bit bigger than A0 paper size in their full size versions in the zipped folder below so if you want to take a really close look, download them. I've also uploaded smaller-sized versions in the same folder. I deliberately didn't include more information on the graphic itself, but at the bottom of the post you'll see the population of each city in 2011 (which relates to the individual city images), plus its urban area and metropolitan area population. The population of Greater London in 2011 was 8.2 million (compared to 4.4 million for the other cities shown). The cities I selected are the English members of the Core Cities group, which now also includes Glasgow and Cardiff.

Click here for a full screen white version

Click here for a full screen black version

Download a zipped folder with black and white versions in different sizes.

Update: the @udlondon people got in touch via twitter to show their attempt at fitting the core cities inside the London boundary - as below - so this inspired me to try the same with the original data. The first image below is the original @udlondon artwork and the next one is my attempt using GIS. Finally, as a reminder that nothing is ever really new, I have added a similar map which we found as part of the JR James urban image archive which we launched last year. This version has 13 different cities.

A manual approach to GIS!

My attempt at the same thing, using QGIS - full size

Some of the boundaries were a bit different in those days

City	Population	Urban area	Metropolitan area
Birmingham	1,085,400	2,440,986	3,683,000
Bristol	428,200	587,400	1,041,000
Leeds	751,500	1,499,465	2,302,000
Liverpool	466,400	816,216	2,241,000
Manchester	503,100	2,240,230	2,556,000
Newcastle	280,200	879,996	1,599,000
Nottingham	305,700	666,358	1,543,000
Sheffield	552,700	640,720	1,569,000

Totals: the population of the 8 city local authority areas is 4.4 million, for their urban areas it is 9.8 million and for their metropolitan areas it is 16.5 million. I may compare metropolitan areas next time, but mapping this is a little more time consuming.

The Age of Buildings in the City of Chicago

Following my last post, on the geography of New York City, I've been exploring other building-level datasets to see what they can offer us in relation to telling us more about the fabric of the cities we live in. This time, I've focused on Chicago's 'Building Footprints' dataset. It's not nearly as detailed as New York's PLUTO data but it does include variables on (e.g.) number of floors and year built. As with the NYC data, it is not perfect but we can still make good use of it to understand the development of the city and its structure. I've mapped the city using number of floors as a proxy for height and shaded it by building age to produce the following overview (blues = older buildings, reds = newer).

Even bigger version

Besides looking relatively interesting, the above graphic also reveals something about the phased construction of the City of Chicago and - possibly - something more about the data itself. As with the New York City PLUTO data, I produced a chart of the 'year built' column just to give me some idea of its distribution. It looks better than the New York City chart but I'm still not convinced it is 100% accurate (the year built data run from 1852 to 2010). 

Were there really nearly 15,000 buildings constructed in 2006 and only 78 in 2000? Possibly, but it would be good to know more about the accuracy of the data. In total there are 820,154 building footprints in the dataset and there are a range of different columns - which you can read more about in the metadata file. Once again, it's pretty cumbersome to work with in a normal desktop GIS setting but my machine can just about handle it.