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.

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