Skyscraper Shadows: A Battle for Light and Space in Our Cities

"We will all be doomed to darkness" is generally the public outcry against skyscrapers, supertalls, and multiple-story menaces. City shade has been the catalyst for a passionate debate on both sides, drawing protests, lawsuits, and rejected proposals. The battle rages on, and to be fair, people aren't wrong. Nobody wants to live in the darkness. But what else are we sacrificing in our cities in the pursuit of sunlight? More on that later, but let's jump to where the war on shadows first began.

The Right to Light

The right to light law dates back to 1663 under the ancient lights doctrine in 17th century England. Basically, if property owners have uninterrupted sunlight, like through a window for 20 plus years, that access to light is protected. This law didn't really make it over the pond, however, and was officially repudiated in the United States in 1959.

The Equitable Building

In New York City, the 38-story Equitable Building changed all that. It towered over its neighborhood and enveloped residents in a seven-acre shadow. The swift outcry led to New York's first comprehensive zoning law, which aimed to regulate how skyscrapers dominated the city. This included enforcing a stepped facade style to create space and light between buildings.

Shadow Analysis

New York is absolutely not the only city concerned about shadows. Plenty of cities require shadow analysis, which is basically what it sounds like: an assessment of proposed buildings and projects and their environmental impact with respect to shading. For example, in Boston, a shadow law from 1990 still restricts any new construction from casting shadows on the Common or Public Garden.

The San Francisco Sunlight Ordinance

Over in San Francisco, the most intense battle of all takes place over the sunlight ordinance. The ordinance dictates that projects over 40 feet high with potential to cast a shadow on a park have to go through a shadow analysis process. Shadows are particularly relevant in terms of San Francisco's climate, where it's chilly year-round. Standing in shade versus the radiant heat makes a difference. But that's not the case in all U.S. cities. You go outside San Francisco, to places like Phoenix, Arizona, and people are begging for shadows. So it changes from place to place in terms of the importance of it.

The shadow ordinance that governs San Francisco was a voter initiative in 1984, meaning legislation won't change it. And it all operates on the basis of proving the insignificance of a shadow. Which is kind of a gray area. The relatively subjective lens of "this is totally insignificant" is fertile ground for people to say, "Well, look, you know, this is significant because the shadow on this park will totally ruin my use and enjoyment of the park." So a lot of projects end up getting scuttled because they cast shadow impacts, including housing projects that are near parks, which you would imagine would be exactly where you'd want to have more housing.

The Need for Housing

The reality is that American cities need to build. In the instance of San Francisco, the city needs to build 82,000 new units from 2023 to 2030, which means building more than 10,000 units per year, which would be nearly three times the city's recent pace.

So What Can Be Done?

Well, with the right planning and architectural designs, shadows can be minimized and meet regulatory requirements for building approval. Take 30 Van Ness for instance, with its angled top that minimizes the shadow on the Civic Center Plaza. It's not that the rising shadows of skyscrapers should swallow all the light of our public parks, which sounds dramatically bad, but there is a need to find a balance.

I would really welcome a discussion about saying, "Look, is there a way that we can actually make more science-based decisions on what is significant?" Is a shadow passing through a park over the course of half an hour, you know, on a handful of days a year, is that significant? But from the perspective of you know, where we would ideally get to, uh, in terms of balancing the complete legitimate needs to sort of preserving sunshine and open spaces in San Francisco against the needs of having a place to house San Franciscans, I think that's a worthwhile conversation to have. And with improving software, the impact and placement of shadows from supertalls can be more accurately analyzed and cities can make informed choices, ones that will hopefully lead to a balance of housing and light for all.