Good Staircase Design: Safety, Comfort, Dimensions and Code Requirements

Save PDF/Print

A well-designed staircase should be easy to find, comfortable to climb and safe in everyday use and during an emergency. Its width, step dimensions, landings, handrails, fire protection and structural system must suit the building and the people who use it. Appearance matters too, but it should follow safe geometry and code compliance.

This guide explains practical staircase design for buildings in India, with dimensional provisions from SP 7:2026, National Building Construction Standards 2026, and structural design references to IS 456 and IS 875. SP 7:2026 is the latest BIS standard listed for this subject. The building rules adopted by the relevant state or local authority, along with fire and approval requirements, must also be checked for each project.

1. Main Parts of a Staircase

• Riser: the vertical height between two consecutive treads.
• Tread: the horizontal step surface, measured without the nosing unless specified otherwise.
• Nosing: the front edge of a tread, which may project beyond the riser.
• Flight: a continuous series of steps between landings.
• Landing: a level platform at the top or bottom of a flight, or between flights.
• Handrail: a graspable rail that supports a person using the stair.
• Guard or balustrade: a barrier along an open edge that helps prevent falls.
• Headroom: the clear vertical space above a stair or landing, measured as specified by the applicable requirements.

See Technical Terms Related to Staircases for additional definitions.

2. What a Staircase Does

A staircase may serve daily circulation, emergency escape or occasional service access. The design depends on its function and occupancy.

Place the stair where occupants can reach it easily from the entrance and main spaces. Keep the approach and landings clear. A door, piece of furniture, low beam or change in floor level should not reduce the required clear width or obstruct movement. For required exits, locate and size stairs in accordance with the building’s occupancy, occupant load, travel distance and fire-safety provisions.

A stair does not replace an accessible route. Where required, provide a lift, ramp or other accessible means of reaching the floors for people who cannot use stairs.

3. Choosing a Stair Type

For required means of egress, use a stair arrangement that meets the applicable fire and building requirements. SP 7:2026 states that curved stairs are not to be treated as part of the means of egress. Its external-stair provisions also restrict the use of spiral stairs. Check the provisions for the building before specifying a curved, spiral or winder stair. For more layouts, see Types of Staircases.

4. Comfortable Stair Dimensions

People climb comfortably when the risers are consistent and the relationship between riser and tread suits a natural walking rhythm. A commonly used design check is Blondel’s formula:

2R + G = approximately 600 to 640 mm

where R is the riser height and G is the going, both in millimetres. This is a comfort guideline, not a substitute for the occupancy-specific dimensional requirements in the applicable code.

Examples that give 600 mm are 150 × 300 mm, 160 × 280 mm and 170 × 260 mm (rise × going). The last combination may suit a private dwelling, but its 260 mm going is below the 300 mm minimum specified by SP 7:2026 for the listed non-residential occupancies.

A comfortable pitch is often in the approximate range of 25° to 35°. Treat this as design guidance rather than a universal statutory limit. A steep stair is harder to climb and descend, especially for children, older people and anyone carrying an item.

Keep every riser and tread in a flight as uniform as possible. Even a small unexpected change at the first or last step can cause someone to trip. Set out the structural stair with the final floor finishes included, so that tiles, stone or timber do not create a different first or last riser. Avoid sharp, oversized nosings and use a finish that remains slip-resistant when wet.

Provide a landing at each change of direction and where required by the applicable rules. A landing should be at least as wide as the stair, and doors should not swing across the required clear width. Winders need careful checking at the walking line and should not be used to bypass requirements for landings or exit stairs.

5. Stair Dimensions in SP 7:2026

The following summary is from SP 7:2026, Part F, clause 4.4.2.4.3. The standard differentiates between a private one- or two-family dwelling and other occupancy categories. Local regulations may set different or additional requirements.

*SP 7:2026 allows a 1.50 m stair width to be accepted for assembly occupancy with fewer than 150 persons. The required number and aggregate width of exit stairs still depend on occupant load and the relevant egress provisions.

SP 7:2026 recommends 12 risers per flight and specifies that a flight should not have more than 15 risers. Do not present 12 as the universal maximum: other regulations or project requirements may impose a stricter limit. The standard also specifies a minimum clear headroom of 2.2 m under a stair and landing. Check the complete clause and related egress provisions, not just this summary table.

5. Landings and Headroom

Landings provide a level area for resting, turning and approaching doors. Size and locate them according to the applicable building and fire-safety requirements. Keep them clear of stored items and arrange doors so that their swing does not obstruct the stair or reduce required exit width.

SP 7:2026 Part F specifies at least 2.2 m headroom in a passage beneath a stair landing and beneath the stair. Beams, columns and other building features must not reduce the required stair width or headroom.

6. Handrails and Guards

Handrails help people steady themselves; guards or balustrades protect people from falling at open edges. They have different functions and should be designed accordingly.

SP 7:2026 Part F calls for a handrail on one side of a staircase narrower than 1.5 m and on both sides where the staircase is 1.5 m or wider. It limits handrail projection into the stair width to 90 mm. Confirm the required height, continuity, strength, openings and fixing details against the applicable design requirements.

Handrails and guards should be securely fixed to supporting construction designed for the required loads. Avoid sharp edges and details that make the handrail difficult to grasp.

7. Accessibility and Ease of Use

Stairs alone do not provide an accessible route for people who use wheelchairs or cannot climb steps. Where required by the building’s use and applicable rules, provide an accessible route, such as a compliant ramp or lift.

The Government of India’s Harmonised Guidelines and Standards for Universal Accessibility in India 2021 recommends that accessible stairs be supplemented by a ramp or lift. Its stair guidance includes a 1,500 mm minimum clear width, treads 300 mm deep, risers no higher than 150 mm, landings at least 1,200 mm deep, consistent step dimensions, warning blocks, and handrails with extensions. Apply this accessibility guidance alongside the current building standard and local requirements.

Good visibility also supports safe use. Provide adequate lighting, contrast at step edges and clear floor identification in public buildings. Maintain warning blocks and other accessibility features so they remain effective.

8. Surface Finish, Lighting and Maintenance

Use a durable, slip-resistant tread finish suitable for the stair’s location and expected use. Keep the step edges visible and provide lighting at the top, bottom and along the flight. On external stairs, consider rainwater drainage, weather exposure and surface wear.

Inspect stairs and landings periodically. Repair loose finishes, damaged nosings, failed lighting, loose handrails and other defects promptly. Keep the route clear of water, dirt, stored items and other slip or trip hazards.

9. Structural Design and Indian Standards

The stair slab, beams, supports and connections must be designed for the relevant dead loads, imposed loads and structural actions. Reinforcement and anchorage depend on the stair configuration and support conditions. A dog-legged stair, a cantilevered stair and a stair spanning between landings may have different load paths.

For reinforced-concrete stairs, IS 456:2000 is BIS’s code of practice for plain and reinforced concrete. IS 875 (Part 2):1987 covers imposed loads for buildings and structures. The structural designer should check BIS for current amendments and status and use the applicable standards and approved project drawings.

Structural drawings should show the stair dimensions, reinforcement, anchorage, supports and connections. Stair reinforcement should not be selected from a generic detail without checking the design and support conditions.

10. Fire and Escape Staircases

A stair that forms part of an exit route may need additional provisions for its number, width, enclosure, discharge, fire resistance, doors, signage and protection from smoke. These requirements depend on the building’s use, height, occupant load and the rules enforced by the relevant authority.

SP 7:2026 Part F states that internal exit staircases should use non-combustible materials and have a minimum 120-minute fire-resistance rating. It also addresses exit discharge, fire doors, service ducts, signage and continuity of escape routes. Check the full fire-safety provisions for the project rather than treating an ordinary internal stair as a fire-escape stair.

Materials and Appearance

The stair should suit the building while retaining clear, safe edges and slip-resistant surfaces.

Coordinate the stair’s colour, lighting and balustrade with the interior, but keep step edges easy to read. Storage or other uses below a stair should not compromise the required headroom, fire separation, escape route or access to services.

Staircase Design Checklist

Before construction, confirm that:

1. The stair type and clear width suit the occupancy and applicable rules.
2. Riser and tread dimensions are within the required limits and consistent.
3. Flight and landing arrangements comply with the applicable provisions.
4. Headroom is adequate at the stair and beneath landings.
5. Handrails and guards are correctly located and securely fixed.
6. Treads are slip-resistant, visible and maintained.
7. Doors, services and structural elements do not obstruct the stair or escape route.
8. Accessibility and fire-safety provisions have been addressed.
9. Structural dimensions, reinforcement and connections match the approved drawings.
10. Finished step dimensions have been checked after the floor and tread finishes are installed.

Conclusion

A good staircase is safe, comfortable and appropriate for the people and building it serves. Its design requires coordinated decisions about width, riser and tread dimensions, landings, headroom, handrails, guards, accessibility, fire safety and structural support.

For projects in India, use SP 7:2026, relevant Indian Standards and the building and fire-safety requirements adopted by the local authority. Stair dimensions depend on occupancy and project conditions, so confirm the applicable provisions before design and construction.

Frequently Asked Questions