Sunday, June 6, 2021

Hiding the Cost of Parking Underground

There's a six-floor, mixed-use apartment building that's been under construction in my neighborhood since last fall. When it got started, there were a lot of complaints about the noise created from the excavation and "pile-driving" on the site. It was very loud for much of the day. There were many trucks coming and going. 

The plans called for around .75 parking spaces per living unit (which is not much as things go in the U.S. these days), all of which are underground — but still, that's a lot of spots for a six-floor building with around 200 apartments in it.

Each one of those "structured" parking spots costs about $50,000 to build here in Minnesota, I've known for a while. $50,000 apiece!

But I didn't know the details of what went into building the parking area exactly.  

This Twitter thread from Luke Klipp filled me in.

What is the practical effect of all the parking that most cities require be built with new housing or commercial buildings? ....

While I shared a few months ago about parking requirements more generally, I'd like to now explore more of the logistics issues and implications of parking requirements as it relates to... just getting all that parking built.

In cities like LA, much of the required parking gets built underground - out of sight, out of mind, right? - and can take 6-12 months to build, at $80K per parking space. Anyone who rents or buys a home in that building will pay for that.

For those who follow these things, maybe none of what I've said so far is new, but... have you thought about just the sheer amount of work required to meet these requirements? It's quite complex and an ecological nightmare to boot.

Most new housing projects start out by first hammering massive steel beams into the ground along the project perimeter, either as a solid wall, or with a set distance between beams that will be filled in with large boards stacked as makeshift walls during excavation.

The more levels of underground parking to be provided, this basic first step gets incredibly more complicated and much more expensive. It's not just the materials, but the challenges transporting them. (just Google "steel beams crash").

Excavation involves removing thousands of tons of soil, which has to be taken somewhere. It typically goes to a dump. So all this soil that's been in the ground for thousands of years is either thrown out or used as fill somewhere else.

Excavation takes months and is followed by installing tons of rebar and concrete forms. That is of course followed by pouring a LOT of concrete.

And concrete has a huge CO2 footprint. If global concrete production were its own country, it'd be the world's third-largest emitter of CO2, behind the US and China, and ahead of India and Russia. Each cubic foot of concrete emits 140 lbs of CO2. At 300 square feet for space and egress, a single parking space needs 150 cubic feet of concrete, emitting 21,000 lbs of CO2. That's the output of ~1,000 gallons of gas. (calculation assumes 6" concrete thickness)

For a Toyota Prius, fetching 54 miles/gallon, the concrete needed for just one parking space emits as much CO2 as the car will emit by going ~54,000 miles. And most cities typically have at least 3-4 spaces per car.

By the time the hole is excavated, soil disposed, rebar laid, and concrete poured, with most housing developments it has been 9-12 months of work. The rest of a building's construction will take that or a little longer.

Which is to say, *just* the parking construction takes about as long to build as the housing it will support, and all that time is money, which gets rolled into what people will eventually pay to rent or buy that new housing.

And when it's all done, the parking that most cities require to be built in new housing doesn't even all get used. This Seattle survey found occupancy usually no higher than 65%, which is pretty standard.

While the Seattle survey is fairly unique (cities rarely check to see if their requirements make sense), here's a Berkeley, CA survey of parking occupancy in new residential developments with similar findings (in their case, 55% occupancy).

And... a new study found "residents in buildings that guaranteed one parking spot per unit had double the rate of car ownership of residents in buildings without parking... parking supply more strongly predicts car ownership than transit access."

Which is to say, the strongest predictor of people's choice to buy and use a car is the *availability* of parking. Provide the parking (and, oh yeah, make them pay for it), and they'll use it.

In sum, in order to meet arbitrary parking requirements, new housing and commercial developments tear big holes in the ground, dispose of gobs of soil, and pour tons of CO2-producing concrete, all to have more parking than we need and to incentivize more people to drive.  

Someday people will look back on this time and wonder why we couldn't see how utterly absurd these requirements are and the untold damage they do.

Until then, please support [efforts to remove parking minimums wherever you are located] and let's be real about the damage these requirements are doing. (emphasis added)

Imagine if that apartment building near me was being built without all that parking. The nearby residents would have been a lot happier with a quieter construction process, for sure, and the environmental damage in the short term would be less. In the long term as well, as the building's occupants are discouraged from owning cars. 

Saint Paul's City Council will soon be voting on whether to support eliminating parking minimum requirements. I support their elimination for all of these reasons. 

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