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Why Window Washing Is Designed Into a Slender Tower

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By Michael Stern, JDS Development Group On the facade drawings of a tower there is a note, small and usually pushed to the corner of an elevation sheet, that says every exterior surface must be reachable by the building maintenance unit. Nobody argues with it in a design meeting because it reads like housekeeping. It governs the shape of the building more than most of the lines drawn beside it. I am writing this for developers, architects and facade consultants who are about to draw a setback or a slender floor plate and have not yet asked who will clean it. The note is the first place that question gets answered, and on a tall narrow building the answer is a good deal more physical than the note suggests. A window gets cleaned and a panel gets inspected by someone, standing somewhere, held by something. That sentence is the whole subject of this piece, and each of its three parts takes up room in the building. The facade note decides roof equipment What the note says is short. A...
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What Preservation Review Asks of a Ground Floor Storefront

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By Michael Stern, JDS Development Group On a designated building the masonry pier standing between two ground floor openings is usually what decides the storefront. It carries load, it is part of what was designated, and the width it keeps is width the display window never gets. I am writing this for developers taking on a conversion, for the restoration architects who will draw the base, and for the retail teams who arrive late and find most of their decisions already made. The base of an old building is the part a person can touch and the part that has been rebuilt the most. Floors above the second tend to survive by neglect. The ground floor has been reworked for whatever business occupied it, which is why by the time we buy the building the storefront is often the least historic thing on the facade and the most closely reviewed. That gap between what is there and what is protected is the first thing to establish. The designation report describes the building the city chose to p...
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Why Fabricators Join the Design Team on an Unusual Building

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By Michael Stern, JDS Development Group The question comes up on almost every building with few precedents, and it almost always comes from an architect. Why is the fabricator sitting in this meeting when the drawings are not finished? It is a fair question, and the answer decides whether the detail on the page can be built at all. The knowledge of what can actually be made sits in the shop that will make it, and it has to arrive while the drawing can still change. This is for architects, structural engineers and development teams deciding whether to bring a trade contractor into design, and how early. What does design assist mean on a building with few precedents? Design assist brings the company that will fabricate a system into the design phase, working under the design team, to test whether a detail can be made. The drawings remain the architect's and the engineer's. The shop is there to answer a narrow question. Can this joint be cut, welded, shipped and hung in the ...
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Lot Coverage Rules Decide How Much Ground a Tower Takes

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By Michael Stern, JDS Development Group Every site carries a limit on how much of its own ground a building may stand on, and that limit is settled in plan long before anyone draws a section. Two of our towers answer it in opposite directions, and what separates them is a decision about plan rather than about size. This is written for the developer, the architect and the zoning consultant standing over a constrained lot, deciding a footprint. The footprint is the decision that closes the most doors behind it. 111 West 57th Street is the tallest and most slender residential building in the Western Hemisphere, so it stands on very little ground and takes its area upward. The American Copper Buildings occupy a former Con Edison site as twin towers with open ground held between them. One question about the ground, two answers. What does lot coverage actually measure? Coverage is the portion of a zoning lot that a building would cover when the lot is viewed directly from above. It is ...
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Why a Tall Tower Moves With the Sun

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By Michael Stern, JDS Development Group Designing for movement rather than against it is an old admission in building practice. It came from watching real structures in the weather and noticing that the face of a building the sun is on runs warmer than the face in shade, so the two sides of one frame want to be different lengths at the same moment. This is for developers, facade consultants and structural engineers deciding how much tolerance a tall building needs and where to spend it. On a low building the difference is small enough to absorb without much thought, and the convention that grew up around it looks like housekeeping. On a tower the same effect accumulates over height, and the housekeeping becomes the design. Why does a tall building move when the sun hits one side? Because the sunlit face gets warmer than the shaded face, and warm material is longer than cool material. One side of the frame grows while the other does not, so the tower curves gently toward the cooler...
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What Changes When a Landmark Sits in a Historic District

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By Michael Stern, JDS Development Group The first document I read on a site with an old building on it is the one that designated that building, and it tells me more about what the project can become than the survey does. Two buildings can stand on the same street, built in the same decade, and answer to different rules, because one was designated on its own and the other is protected by the district drawn around it. This is written for developers, architects and preservation professionals working out what a conversion may ask for before anyone draws it. What the designating document actually says The report that creates a landmark is a reasoned document rather than a label. It names what is being protected, states why it is being protected, and then describes the features that carry those reasons. Everything a reviewer does afterward refers back to that description. For an individual landmark the subject is one building, so the reasons are specific to it and the significant featu...
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Why an Unlisted Product Is Approved One Project at a Time

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By Michael Stern, JDS Development Group On every building I have worked on that had few precedents, there has been at least one assembly sitting in a laboratory with nothing behind it in any code table. The thing is real. It is fabricated, instrumented, waiting for a load, and it has no permission to be installed in the building it was made for. That gap, between a product that exists and a product a city will accept, is the subject here. I am writing it for developers about to commit to something unusual, for architects of record who will carry the filing, and for construction managers holding a schedule around it. The route through the gap is well worn, and almost nobody plans for it the first time. A code carries what has already been proven, written down as classifications, standards and acceptance criteria. A product outside that record is not forbidden, only unrecognized. Unrecognized is a condition with a procedure attached to it. What happens when the building code has no ...
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