The discussion around the proposed plans for a series of new towers rising up to 1,070 feet within the Transit Center District naturally turns to new shadows, the effects of which are extensively covered in the second appendix of the Transit Center District Plan and Transit Tower Environmental Impact Report.
For those who haven’t managed to make it all the way through the nearly thousand page report, we offer a few summary excerpts with respect to the proposed towers’ shadows:

Shadow effects of the draft Plan were analyzed by computer generation of shadows that would be cast by the proposed Transit Tower as well as shadows that would be cast by other buildings that could be built with implementation of the draft Plan….For potential future buildings other than the Transit Tower, shadows analyzed are based on massing models representative of potential future development in the Plan area.

[The shadows] from several potential future Plan area buildings at 500 feet in height or greater would reach a number of parks subject to Section 295 controls, including Union Square, Justin Herman Plaza, Portsmouth Square, St. Mary’s Square, Maritime Plaza, and Boeddeker Park.

With one exception, shadow from any given potential building would cover part of any affected Section 295 park for less than 45 minutes per day over a period of time ranging from 4 to 12 weeks (one to three months) per year; the exception would be that Union Square would be newly shaded by up to about one hour per day, over a period of six months, by a 600-foot tower addition to the southwest corner of the Palace Hotel on New Montgomery Street. Most new shadow on Section 295 parks would be in the early morning hours, except that Justin Herman Plaza would be newly shaded in the early afternoon in late fall and early winter.

Union Square, because it is in a retail and tourist hotel neighborhood, is generally not heavily used during the early morning hours (before 8:00 a.m.) when much of the new shadow from Plan area buildings would fall on the park. Between 8:00 a.m. and 9:00 a.m., when shadow from the Palace Hotel tower would fall on Union Square, activity is increased, although there is substantially more pedestrian activity on the sidewalks surrounding Union Square at this time than in the park itself, as many people pass Union Square when walking to work and other destinations.

Portsmouth Square, at the eastern edge of Chinatown, a very dense residential neighborhood, is relatively heavily used even between 8:00 a.m. and 9:00 a.m., when new shadow from Plan area buildings would fall on the park. Much of the activity in Portsmouth Square at this time of day consists of individuals, many elderly, exercising.

St. Mary’s Square, although near the southern edge of Chinatown, is not as heavily used as Portsmouth Square. However, it is used by people exercising in the early morning, when new shadow from Plan area buildings would fall on the park.

Justin Herman Plaza, which would be newly shaded in the early afternoon in late fall and early winter, is heavily used during the midday period by persons traveling to and from the Ferry Building, tourists, street vendors, and lunchtime office workers and strollers.

The non-Section 295 public open space that would be most greatly affected by Plan area development is Rincon Park along the Embarcadero. This open space would be newly shaded in the late afternoon throughout much of the year, except from mid-fall through mid-winter, by the Transit Tower, 181 Fremont, the 50 First Street project, and potential 700-foot buildings at the Golden Gate University site and at 350 Mission Street.

Click on either of the images to enlarge. Keep in mind it’s the orange bits (“Net New Shadow”), not simply the building outlines, that really matter. And beyond the effect on parks, plugged-in people might also note the unrestricted effects on other buildings.
The Plan For San Francisco’s Tallest Tower And Transit Center District [SocketSite]
Hines And Pelli Clarke Pelli Bid The Most (And Get The Transbay Nod) [SocketSite]
Transit Center District Plan and Transit Tower EIR Second Appendix []
San Francisco Planning Code Section 295: Shadow Restrictions []

20 thoughts on “Shining Light On The Shadows Of The Proposed Transit District Towers”
  1. I’m not about to read through 1,000 pages, so I’ll leave this to our more intrepid readers – do they mention the type of weather/cloud cover likely to happen at these different times of day and year? Is there a percentage comparison of the current cloud-caused shadows on parks, compared to current and/or potential building-caused variety?

  2. We should build everything 600 feet underground. No shadow. Problem solved.
    I will not comb through the 1000 pages neither. I’ll wait for the movie.

  3. People joke, but this shadow business will be a serious impediment to any large scale construction in the area. I am all for sunshine, but the laws we have in SF are too restrictive, and too biased towards no development.

  4. Extending growth from downtown to South of Market has always made sense, but in the context of shadows there would seem to be no other place with any possibility for tall buildings.

  5. The shadows cast from the tall buildings in New York and Chicago have really kept those from becoming world-class cities. So this is certainly worthy of more 1000-page reports.

  6. There is plenty of sun in Lafayette, San Rafael, and Palo Alto.
    Yo! Cities have shadows.
    And in time, when the periphery of Golden Gate Park is upzoned for tall buildings, there too shall be shadows.

  7. The shadow issue is an important one but should not be a show-stopper. The area of the Transit Center should be the densest (and therefore tallest) part of downtown BECAUSE IT IS ADJACENT TO TRANSIT. If the buildings cast some shadows, sorry about that but it can’t be helped. It IS downtown, after all, not the beach or a residential area.

  8. What about the towers that are already there that are just as tall or taller (Transamerica, 101 California, 50 Fremont, Millennium) are they not casting any shadows at all?
    [Editor’s Note: As noted in the image keys above, the color grey represents existing shadows, of which there are a few.]

  9. The shadow argument primary use is to stop growth in San Francisco.
    Like other posters have stated, there will always be shadows in some portion of the City due to Financial Center buildings, or our foggy weather.

  10. The obvious solution is to make a building entirely of transparent structural glass. But don’t let any people in it; people cast shadows.

  11. Fog should totally be outlawed. Imagine how much less shadows there would be without fog!
    Maybe buildings could be equipped with mirror arrays at their crowns to redirect sunlight on shadow areas.

  12. “The obvious solution is to make a building entirely of transparent structural glass.” Yup, but then you’ve got the problem of birds trying to do a fly through … remember that issue?!

  13. Really, 13 comments total for what is the most important development policy and opportunity for this city in decades? Meanwhile, a post above this about a single family home receives 66 comments.
    I thought Socketsite had more worldly readers and posters than this. Blah, this site’s turned so dull.

  14. In a bad economy, all that BS like light and quality of life gets tossed out the window.
    We’d turn this town into a crowded slum if it meant more union construction jobs, property taxes, a free transit hub and denser working population providing more sales taxes without requiring additional infrastructure. At least the politicians think that way.
    Sure, it’s short term thinking, and we’ll be stuck with the resulting problems for the next 100 years, but honestly, the population cares more about the next 49ers game than shadows. Besides, the only parks impacted are primarily for tourists, and we never have any problems raising the hotel taxes because none of us pay them.

  15. “Blah, this site’s turned so dull.”
    So then, don’t post here. Your comment was the one that’s dull.
    “In a bad economy, all that BS like light and quality of life gets tossed out the window. ”
    Thank goodness, it makes up for the ridiculous NIMBY overcompensation during the rest of the time.
    “Besides, the only parks impacted are primarily for touristshomeless.”
    Fixed that for you.
    What we need here are more and taller buildings. This is just one of those regulations to prevent growth that the NIMBYs here love.

  16. Building out the Transbay area has little overall effect on parks. Most of the parks are only affected when the sun in very low in the sky.
    However, the shadow issue is a good argument for concentrating towers downtown, where the impact of new shadows overall is small.

  17. Excellent point, Dan, and I expect that will be the conclusion reached when the Transbay plan is finally approved. Crazy as it may sound, I have faith this city can still get some things right.

Leave a Reply

Your email address will not be published. Required fields are marked *