March 2017

Incompatibility: Rooftops

by Don Friedman on March 31, 2017


Sometimes the incompatibilities we deal with are not inherent in the physical material of the buildings but are the result of multiple conflicting regulations. A good example of this is found at roof tops of landmarked buildings. There are three regulations that I’m concerned with, all of which make perfect sense on their own but they don’t play well together.

First, the Landmarks Commission is concerned about the roof line because that is one of the prominent visual features of a building. So changes to the status quo will be closely examined and may be rejected.

Second, roofs have to have safety handrails or parapets to keep people from falling off. Even unoccupied roofs typically need handrails. So when we’re altering a building and doing any kind of work on the roof, we’ll need a handrail to get approval.

Third, and this is relatively new, we are required to have a clear path across the roof for firefighters. This may include short flights of stairs to get past dunnage or other obstructions raised above the roof surface.

Putting the handrail far enough back so that it’s not visible often puts it in an awkward location relative to bulkheads or mechanical equipment. Putting raised platforms (with handrails) over dunnage raises the visible height of the dunnage. Using a heavier handrail or parapet in an attempt to match an older building’s facade makes it more likely that the handrail or parapet will qualify as an obstruction rather than a minor interruption on the path. The problem is defined as looking for a solution that’s safe but not visible, allowing free access for firefighters but blocking falls for occupants.

There are solutions and they are, of course, compromises. But it turns out that three good and useful ideas, in combination, are not really compatible.

Misleading Intuition

March 30, 2017

In a recent conversation with an old friend who is simultaneously interested in and baffled by building engineering, I decided that the success of modern building technology has hidden itself. It’s ubiquitous, so no one thinks about it, so no one understands it. The picture above is the old New York Times building under construction in […]

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What Do We Do All Day?

March 29, 2017

George W. Melville, Chief Engineer of the United States Navy Bureau of Engineering, in the 1890s. A serious man with a serious hat. We’re fairly busy right now. Also, we have two part-time student interns learning the basics. When you combine those two facts, I’ve been spending a lot of time thinking about how we all […]

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Where Do Skyscrapers Come From?

March 28, 2017

The World Building on Park Row. The Skyscraper Museum has put up the videos of the symposium three weeks ago. In layman’s terms, my mug is all over them…I mean to say that there’s some good stuff here. In video one, Carol Willis explains the context and all of the speakers throw in a few […]

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A Long Time Coming

March 27, 2017

This article on the adaptive reuse of Sears Catalog Warehouses rang two bells for me. First, as I’ve been harping on lately, adaptive reuse is in my opinion the best way to save old buildings. They have to have a use or we’re saving them as over-large sculptures, or monuments to our egos, or something […]

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Women Can Build

March 26, 2017

Via DNAinfo, an exhibition called “Women Can Build,” on women in transportation infrastructure jobs, is currently on the web and on display in cases on Water Street, at Gouverneur Lane and Pearl Street.

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Like A Comic-Book Villain

March 25, 2017

Rust looks as bad as it is.

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They Are Long Gone And I Hate Them Anyway

March 24, 2017

That is a picture of a condition exposed during demolition. If the people responsible for that condition were in the room when i first saw it, I’d be gulping down ice cream to sooth a throat made raw by screaming at the top of my lungs “What is wrong with you people?” In short, this […]

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Recertified As A B Corp

March 23, 2017

Old Structures Engineering has been recertified as a B Corp, a process that takes place every two years. This was our first recertification and my overall feeling is that it’s nice to know that our original certification wasn’t a fluke. There were two interesting aspects to taking the B Assessment for the second time. The first […]

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Historic Structural Detail: Assembly Required

March 22, 2017

It’s been a while since I’ve done one of these posts, possibly because my attention has wandered to more fertile fields of criticism. In any case, the picture above is a nice illustration of just how much cast-iron facades were kits to be assembled. (Note that there’s some flash burn on the left side of the […]

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