Question 1

What is the most common residential stair type?

Accepted Answer

Straight stairs are the most common in residential construction. They are the simplest to build, meet all building codes, and are easiest for moving furniture. L-shaped stairs are the second most common, found in two-story homes with limited floor space.

Question 2

Which stair type is hardest for moving furniture?

Accepted Answer

Spiral stairs are the hardest for moving large furniture. The tight central column, narrow treads, and continuous turning make it nearly impossible to navigate sofas, mattresses, or large appliances. Winder stairs are the second hardest due to their narrow inside treads.

Question 3

What are the building code requirements for stairs?

Accepted Answer

The IRC requires a minimum stair width of 36 inches, maximum riser height of 7.75 inches, minimum tread depth of 10 inches, and minimum headroom of 6 feet 8 inches (80 inches). Landings must be at least as wide as the stairway.

Question 4

What is the difference between winder stairs and L-shaped stairs?

Accepted Answer

Both turn 90 degrees. L-shaped stairs have a flat landing platform at the turn, giving you room to pivot furniture. Winder stairs replace the landing with pie-shaped treads that taper toward the inside, making the turn continuous but much harder for moving.

Question 5

Are spiral stairs code-compliant for a primary staircase?

Accepted Answer

In most US jurisdictions, spiral stairs can only serve as a primary staircase under limited conditions (IRC R311.7.10.1): minimum 26-inch clear width, tread depth of at least 7.5 inches at 12 inches from the narrow edge, and headroom of at least 6 feet 6 inches.

Question 6

How wide do stairs need to be for moving a couch?

Accepted Answer

You generally need at least 36 inches of clear width between walls or handrails. Standard couches are 32-40 inches deep, so they must be tilted vertically. For the turn at a landing, you need landing depth equal to or greater than the stairway width.

Type	Width (in)	Headroom (in)	Moving Difficulty	IRC	IBC	ADA
Straight StairsSingle straight flight, most common residential type	36	80	simple	✓	✓	—
L-Shaped Stairs90-degree turn with landing platform for reorientation	36	80	moderate	✓	✓	✓
U-Shaped Stairs180-degree turn with parallel flights and landing	36	80	moderate	✓	✓	✓

Type	Width (in)	Headroom (in)	Moving Difficulty	IRC	IBC	ADA
Quarter Winder90-degree turn with pie-shaped wedge steps, no landing	36	80	complex	✓	—	—
Half Winder180-degree turn with wedge-shaped steps, no landing	36	80	complex	✓	—	—

Type	Width (in)	Headroom (in)	Moving Difficulty	IRC	IBC	ADA
Spiral StairsCircular spiral around center pole, space-saving design	60	78	complex	✓	—	—
Circular StairsGentle curved arc, wider and more gradual than spiral	96	80	complex	✓	✓	—
Curved StairsGradual arc with consistent width, gentle curve	42	80	moderate	✓	✓	✓
Helical StairsContinuous curve without center pole, free-standing design	84	80	complex	✓	✓	—
Elliptical StairsOval-shaped curved staircase, architectural statement piece	108	80	complex	✓	✓	—

Type	Width (in)	Headroom (in)	Moving Difficulty	IRC	IBC	ADA
Floating StairsOpen treads without risers, wall-mounted cantilevered design	36	84	simple	✓	✓	—
Cantilevered StairsTreads extend from wall with no visible support structure	36	84	simple	✓	✓	—

Type	Width (in)	Headroom (in)	Moving Difficulty	IRC	IBC	ADA
Butterfly StairsSplit staircase with two flights diverging from central landing	72	84	simple	✓	✓	✓
Imperial StairsGrand monumental staircase with wide treads and large landing	96	96	simple	—	✓	✓
Geometric StairsAngular modern design with sharp geometric turns	42	84	moderate	✓	✓	—
Split LevelShort flights connecting half-levels in split-level homes	36	80	simple	✓	✓	✓
Custom/OtherNon-standard or unique stair design requiring custom measurements	36	80	unknown	—	—	—

Complete Guide to Stair Types — 23 Types Compared

Basic Stairs

winder Stairs

circular Stairs

modern Stairs

Specialty Stairs

Space-Saving Stairs

emergency Stairs

retractable Stairs

Moving Difficulty Ranking

Related Fit Calculators

Related Guides

Standards Referenced

Frequently Asked Questions

What is the most common residential stair type?

Which stair type is hardest for moving furniture?

What are the building code requirements for stairs?

What is the difference between winder stairs and L-shaped stairs?

Are spiral stairs code-compliant for a primary staircase?

How wide do stairs need to be for moving a couch?

Related Reading

Mastering Moving Day: The Ultimate Guide to Spatial Planning

How to Move Heavy Furniture Without Hiring Movers

DIY Home Renovation: Your Complete Dimension Guide

Type	Width (in)	Headroom (in)	Moving Difficulty	IRC	IBC	ADA
Alternating TreadSpace-saving steep stairs with alternating step pattern	24	78	simple	✓	—	—
Ship LadderVery steep ladder-like stairs at 60-degree angle	20	72	simple	—	—	—

Type	Width (in)	Headroom (in)	Moving Difficulty	IRC	IBC	ADA
Fire EscapeExterior emergency exit stairs with metal grating	32	78	moderate	—	✓	—
Scissor StairsTwo interlocking independent stairways in one shaft for fire safety	44	80	simple	—	✓	✓

Type	Width (in)	Headroom (in)	Moving Difficulty	IRC	IBC	ADA
Folding StairsCollapsible attic or loft access stairs that fold into ceiling	24	84	simple	✓	—	—
Retractable StairsPull-down attic access stairs that retract into ceiling	26	84	simple	✓	—	—