---
title: "Elements of a staircase"
subject: "Building Technology"
chapter: 5
key: "semester_6/building_technology:stair-elements"
source: https://www.bctengineer.com/q/semester_6/building_technology/stair-elements
site: BCT Engineering
---

# Elements of a staircase

Building Technology · Chapter 5: Stair, lifts and escalators

- Asked in: 2069 Bhadra, 8 marks
- Video: [Technical Terms in Stairs | Stairs | Building Construction](https://www.youtube.com/watch?v=V25plrWEH1k) — SGK Online Education
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/stair-elements
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-5

## Question

Define stair. Illustrate the elements of staircase with figure.

## Short answer

Stair is set of steps connecting floors. Elements include step (tread+riser), nosing, flight, landing, going/rise, waist slab/stringer, soffit, handrail, baluster, newel post, headroom, winder, pitch line.

## Answer

A **stair** is a set of steps (a series of risers and treads) that connects floors at different levels, giving access from one storey to another, usually with landings and a balustrade.

#### Elements of a staircase
A stair has the following essential elements:
- **Step:** one riser plus one tread; steps are the basic unit.
- **Tread and riser:** tread is the horizontal surface (250-300 mm), riser the vertical face (150-175 mm).
- **Nosing:** the rounded projecting edge of the tread (about 25 mm).
- **Flight:** an unbroken series of steps between landings (3 to 12 steps).
- **Landing:** level platform at the ends of a flight or between flights; quarter-space or half-space.
- **Going and rise:** horizontal and vertical measurements of a step or flight.
- **Waist slab / stringer:** the inclined slab or beam which supports the steps.
- **Soffit:** underside of the flight.
- **Handrail, baluster and newel post:** the balustrade that protects the open sides; handrail about 0.9 m high.
- **Headroom:** clear height above the steps (min. about 2.0-2.2 m).
- **Winder:** tapered step used to turn the stair in restricted space.
- **Pitch line:** imaginary line joining the nosings; its angle with the horizontal is the pitch.

```text
        handrail
          /|  baluster
   newel /_|__
        |    |  nosing
  riser |____|__ tread
  ______|
   going <--->
```

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is a stair?
   A. A set of steps connecting floors at different levels
   B. A ramp without steps
   C. A mechanical hoist
   D. A roof access hatch
   Answer: A. It has risers and treads, usually landings and a balustrade. (Key point: Stair def)

2. What is the nosing?
   A. Underside of the flight
   B. Rounded projecting edge of the tread, about 25 mm
   C. Top of the newel
   D. Level platform
   Answer: B. It gives foot space and a neat edge. (Key point: Nosing)

3. What does the waist slab or stringer do?
   A. Protects the open sides
   B. Turns the stair in tight space
   C. Supports the steps as the inclined slab or beam
   D. Marks the pitch angle
   Answer: C. It carries the steps and loads. (Key point: Waist slab)

4. What is a winder?
   A. Vertical post of the balustrade
   B. Level landing
   C. Imaginary line through nosings
   D. Tapered step used to turn a stair in limited space
   Answer: D. Winders radiate to change direction. (Key point: Winder)

## Related in Building Technology

- [Elements and types of stair](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Astair-elements-types) — Building Technology, chapter 5, asked 2×
- [Stair elements, ladders, lifts, elevators and ramps](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Astair-elements-ladders-lifts) — Building Technology, chapter 5
- [Vertical circulation elements; RCC dog-legged stair](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Astair-circulation-068ba) — Building Technology, chapter 5
- [Staircase for public building (5.5 m × 6.5 m)](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Astair-public-5p5x6p5) — Building Technology, chapter 5
- [Open-well staircase (6.0 m × 3.5 m hall)](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Astair-064j) — Building Technology, chapter 5
- [Quarter turn stair, 5.5 m by 4.0 m](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aquarter-turn-stair-residential-lobby) — Building Technology, chapter 5