Stair, Elevator, and Conveying System Planning and Placement

How architects plan and position stairs, elevators, escalators, and other conveying systems within buildings to satisfy vertical circulation, egress, accessibility, and programmatic requirements during the programming and analysis phase.

ARE · Programming & Analysis

Overview

Stairs, elevators, and conveying systems are the vertical spine of any multi-story building. Their placement during programming doesn't just affect circulation; it shapes the structural grid, floor plate efficiency, egress capacity, and accessibility compliance for the entire project.

Think of it this way. A stair core in the wrong location can choke a floor plate, force awkward corridor layouts, and blow your net-to-gross ratio. An elevator bank positioned without considering lobby queuing can create bottleneck conditions that persist for the life of the building. These decisions lock in early and resist change.

During programming, you're assessing both horizontal and vertical spatial relationships. Objective 4.4 of the PA division asks you to evaluate shafts, stairs, conveying systems, atriums, and other multi-level spaces alongside horizontal relationships like circulation, entry, loading, assembly, and MEP spaces. The ARE tests your ability to analyze these relationships and make evaluative judgments about placement, not just recall code minimums.

Vertical transportation planning intersects code compliance (IBC stair dimensions, egress capacity), accessibility standards (ABA/ADA elevator requirements), fire safety (pressurized stairwells, firefighter access elevators), and building efficiency (core-to-lease-span ratios). Getting this right during programming prevents costly redesign in later phases. Miss it, and you're reworking structural grids and floor plates well into design development.

Essential

Vertical circulation planning is one of the first structural commitments you make during programming. Once you fix the location of stair and elevator cores, almost every other spatial decision flows from that choice. Floor plate geometry, corridor routing, structural bay spacing, and net-to-gross ratios all depend on where you stack your vertical elements. Types of Vertical Circulation Stairs serve two distinct functions: everyday circulation and emergency egress. A monumental stair in a lobby connects floors visually and encourages use, but it typically doesn't count toward egress unless it meets code requirements for enclosure, width, and fire rating. Exit stairs, by contrast, must be enclosed in fire-rated shafts in most multi-story buildings and must discharge directly to the exterior or through a protected path at the exit discharge level. Elevators fall into several categories relevant to programming. Passenger elevators handle routine vertical travel in buildings over two or three stories.

Professional

Consider a 12-story federal office building with 250 occupants per floor. The architect must determine the number and placement of exit stairs, the elevator configuration, and the core strategy during programming. The egress calculation starts with capacity. At 0.3 inches per occupant, 250 occupants require 75 inches of stair width per floor. Two 44-inch stairs provide 88 inches, which satisfies the requirement. But remove the largest single exit per the code's lost-exit provision: a single 44-inch stair handles only about 146 occupants, not 250. So two stairs won't work. Three 44-inch stairs provide 88 inches with one removed, still adequate. The architect might instead use two wider stairs (say, 56 inches each), which gives 56 inches with one removed, enough for roughly 186 occupants. Still short. Three stairs it is. With the highest occupied floor at roughly 150 feet above grade, pressurized stairwells are mandatory per GSA standards.

TLDR

Stair and elevator cores are among the first elements fixed during programming; their placement dictates floor plate efficiency, egress routes, and structural systems.
IBC minimum stair width: 44 inches clear (for occupant loads of 50+). Maximum riser: 7 inches. Minimum tread: 11 inches.
Egress stair capacity: 0.3 inches of width per occupant. A 44-inch stair serves roughly 146 occupants per floor.
GSA requires minimum two exit stairs per multistory building; scissor stairs count as only one exit.
Pressurized stairwells: required when the highest occupied floor exceeds 75 feet above fire department access.
Occupant evacuation elevators: required (GSA) when the highest occupied floor exceeds 120 feet.
LULA elevators: minimum 42 inches wide by 54 inches deep (ABA Standards).
Escalators handle high-volume flow but don't count toward egress capacity or accessible routes.
Core strategies: central core (balanced leasable zones), side core (max open floor area), dual cores (distributed egress).
Atriums require smoke control, sprinklers, and don't serve as egress paths. Mezzanines exceeding one-third of the floor below are classified as stories.

ELI5

Picture a building like a stack of pancakes. Each pancake is a floor. Now, how do people move between these pancakes? That's what vertical circulation is about. Stairs are the simplest answer. You walk up, you walk down. But stairs also have a super important job during emergencies: getting everyone out safely. That's why building codes are very specific about how wide stairs need to be (at least 44 inches, which is about the width of a bathtub), how tall each step can be (no more than 7 inches), and how deep the flat part of each step must be (at least 11 inches). These numbers exist because fire safety experts figured out decades ago that stairs need to be wide enough that people don't jam up and block each other during an evacuation. Elevators are the other big piece. They're like vertical buses.

AREProgramming & Analysis

Stair, Elevator, and Conveying System Planning and Placement

2 min read205 words

Where You Put the Stairs and Elevators Changes Everything

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