How scaffold height is measured

Getting this wrong is the most common reason a supported scaffold filing comes back. The rule is short: temporary structures underneath count toward the height, permanent construction does not.

Scaffold on temporary equipment

Where a supported scaffold stands on a sidewalk shed or other temporary equipment, the height of that equipment is included in the measurement. A 34 foot scaffold sitting on an 8 foot shed is a 42 foot scaffold. It needs a permit and a sealed design, and filing it as a 34 foot scaffold will be caught.

This is worth checking on every job where a shed already exists, because the scaffold contractor is often quoting from the deck up while the code measures from the sidewalk.

Scaffold on permanent construction

Where the scaffold stands on permanent construction, such as a roof, a terrace or a building setback, the measurement runs from that surface upward. The building below is not counted. A 20 foot scaffold on the roof of a 200 foot building is a 20 foot scaffold.

Why this trips people up

Two scaffolds of identical size can land on opposite sides of the 40 foot line depending on what they stand on. Since the height determines both whether a permit is needed and whether a sealed design is needed, an error here does not produce a small correction. It produces a filing that has to be redone.

Key facts

On a sidewalk shed

Shed height counts

On a roof or setback

Measured from that surface

Threshold

40 feet

Consequence of error

Permit and design requirement change