© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

© Copyright JosephPrince.com 2020

I

292 mm

Straight flight is the most efficient staircase we would normally use, as it usually does not need a landing unless there are too many steps.

This is a comparison study of a most efficient staircase vs a spiral. For normal staircase, the highest riser allowable is 175mm, the smallest tread allowable is 250mm. For spiral staircase, we measure herewith from the middle of the staircase.

To ensure that we are comparing apple to apple, the fixed parameters as follow:1. riser height of 175mm2. with of staircase is 1000mm.

1000 mm 175 m

m

2.6

3 m

1.00 m

3.50

m

0.25 m

1.10 m

column of 200mm diameter (this item might constribute additional area to the staircase which might not allow for a very accurate comparison.)

Data Straight Flight Spiral

No of Steps 14 14

Diagonal distance between

2 steps305mm 292mm

Total distance 4272mm 4088mm

Area (scenario 1)1m x 3.5m

=3.5m23.142 x 1.1 x1.1 x 315/360 = 3.33m2

Area (scenario 2 without column)

1m x 3.5m =3.5m2

3.142 x 1 x 1 = 3.142m2 (without middle support and 1m wide spiral, with full circle divided equally

to reach the height

360 degrees into 16 partsEach part is 22.5 degrees.14 parts = 315 degrees.

175 m

m

4272

mm

Note: The numbers are rounded to the nearest whole number, therefore there seems to be a discrepancy for the total length for the straight flight. The distance between 2 steps for the straight flight is 305.16mm (round off to 2 decimal places).

1.00 m30

5 m

m

This proves the spiral staircase uses the least area and the shortest distance to gain the height.

Copyright:

Chua Soo HoonRegistered Architect (Board of Architects, Singapore)

Straight flight is the most efficient staircase, as it usually does not need an intermediate landing unless there are too many steps. However, it becomes inefficient if it climbs beyond 2 storeys.

If a spiral staircase is used for more than 2 storeys, we will need to provide a landing of 90degrees which leaves 270degrees to be subdivided into steps.

There is also a hybrid, combining straight flight with winders as shown, this is also very efficient, commonly seen in buses.

column of 200mm diameter (this item might constribute additional area to the staircase.

A 90degrees landing is required when it goes beyond 2 storeys.

Data Straight Flight With Winders Spiral

No of Steps 14 14 14

Diagonal distance

between 2 steps305mm 305-346mm 254mm

Total distancelongest when combined with

landing middle range shortest

Area (with landing)

2m x 4.5m =9m2 2m x 2m =4m2 3.142 x 1.1 x1.1 x 3/4 = 2.85m2

3/4 of a circle is used.

This proves the spiral staircase uses the least area and the shortest distance to gain the height.

305 mm

346 m

m338 mm

254 m

m

2.00 m 2.0

0 m

2.00 m

3.50

m1.

00 m

Copyright:

Chua Soo HoonRegistered Architect (Board of Architects, Singapore)

20200119 SUN1 Slidesstudy of staircases p1study of staircases p2