Brandon Donnelly — Daily insights for city builders. Published since 2013 by Toronto-based real estate developer Brandon Donnelly. — Page 170

Here is an interesting study that looked at the impact of urban highways on social connections within the 50 largest US cities. To measure this, the researchers used Twitter data from 2012-2013, which is a period of time where the default setting in the mobile app was to tag each tweet with the user's precise geographic coordinates.

This allowed the team to generally figure out where a user is likely to live. If you're often tweeting from the same residential address, then there's a good chance that's home. They then looked at things like mutual followship as a measure of social ties. And what they ultimately found was that in all 50 cities, urban highways exhibit a strong barrier effect. They measured this using something they call a "barrier score."

Now this sounds right and supports lots of other evidence that highways divide cities; but Twitter isn't necessarily a place where mutual followship means you actually know the person in real life and you regularly walk down the street to see if they can come out and play. So one of the things that the researchers also did was work to replicate their findings using data from another social network called Gowalla.

I very vaguely remember this platform, but it is/was a social network where users are supposed to connect with people they actually know and share their locations through check-ins. With this data they found that their "barrier score" was even more pronounced , which makes sense given that the platform's social graph should have had, in theory, stronger real-life ties.

But even if you don't believe the social data, these results should make intuitive sense. Highway underpasses and overpasses tend not to be the best environments for pedestrians. They're usually a clear break in a city's urban fabric, which can make people second guess whether they really want or need to cross it.

Cover photo by Tom Barrett on Unsplash

The other night, I went down a Parisian real estate rabbit hole on Twitter. And one of the things that kept coming up was this half joke: The biggest developer in Paris today is the mayor. The reason for this is that the city is targeting 40% of all homes to be public housing by 2035 (of which 30% will be social housing and 10% will be moderately affordable).

Supposedly this is to stem the steady outflow of people from the capital as a result of housing being too expensive. But it means that a lot of new public housing will need to be created. As of January 1, 2021 , the official estimate was 260,563 "logements sociaux" in the capital, which translates into 22.4% of all principal residences.

To hit this 40% goal, the city is going to need to create somewhere around 140,000 new public housing dwellings between now and 2035. So how does it plan to do this? By being a developer, of course. A big part of the strategy seems to be to convert existing buildings (d'adapter l’existant). And to execute on this, the city is leveraging something known as "le droit de préemption."

The way it works is like a right of first refusal clause (ROFR), except that it's not something that was contractually negotiated between market participants, it's just the law. What it means is that if a property owner goes to sell their building and they receive an offer, the city has an automatic ROFR and can choose to buy the building at whatever that third party was willing to pay.

Over the last two years, the city has elected to do this 84 times and has spent over €1.1 billion, according to Business Immo . And since the beginning of this year, they've done it 9 times, spending about €67 million on the following properties:

For those of you who are visual learners like me, here's the first property on the list:

It's certainly ambitious.

But, for the most part, it does not create a lot of net new housing, even though the city is also aiming to buy office buildings, parking garages, and other non-residential buildings. APUR previously estimated that for every 1 unit of new public housing, 0.6 existing units are being demolished. So the most accurate way to think about this initiative is that it represents the socialization of Paris' housing stock into public hands.

This runs in contrast to what we've been talking about recently with cities like Minneapolis and Austin , who have instead added a lot of new market-rate housing in order to temper rents and increase affordability. Paris is reducing its stock of market-rate housing.

At the same time, the city also enacted new policy prohibiting homes that consume more than 450 kWh/m2 from being rented. This is intended to force landlords to renovate, but it will certainly have a further impact on supply, at least in the short term.

It's also worth noting that all of this is happening at a time when Paris' housing market is in broad decline (less transactions, higher days on market, lower prices, and so on). Like Toronto, it started around the middle of 2022. And it's something that Paris hadn't seen since the 2008 financial crisis.

Chart by CoStar via Business Immo ; cover photo by Salomé Watel on Unsplash

Since 2009, policymakers in Minneapolis having been implementing land use changes to encourage more housing supply. Some of these changes have included eliminating parking minimums , encouraging multi-family buildings up to 6 storeys on commercial corridors, establishing height minimums in high-density zones, and permitting triplexes on all residential lots. It's, from what I can tell, the type of stuff that many cities have now done or are looking to do. But it seems to have worked remarkably well in Minneapolis. According to The Pew , between 2017 and 2022, the city issued permits for nearly 21,000 new homes and nearly 87% of them were for homes in buildings with 20 or more suites.

This is interesting. It tells us that the triplex policies don't seem to be doing all that much, but that the market has certainly taken to larger multi-family projects. This is an accomplishment. Even more importantly, though, is that it seems to be having a measurable impact on average rents. During the same time period as above, Minneapolis increased its housing stock by 12% and average rents increased by only 1%. Whereas the rest of Minnesota only increased its housing stock by 4% and, maybe as a result, average rents went up by 14%. Changes in homelessness also look dramatically different.

It looks to be a similar story to what's playing out in Austin: increased housing supply is tempering rent growth. (Okay, in the case of Austin it seems to be causing rents to fall .) What I would be interested in seeing now is a further breakdown of this 87% share. Because 20 suites is a different kind of build than 300 suites. It's different for developers and it's different for cities. And I'd like to know if the market is favoring one over the other, or if it's building apartments at all scales. If the city is in fact building lots of new apartments at multiple scales, then this is even more of an accomplishment. It means there might be no "missing middle."

Cover photo by Eastman Childs on Unsplash