Parametric stairs

I have a 2-level flat and I am trying to figure out the best shape and parameters for the staircase. It will probably be made from concrete. It will definitely need to be L-shaped or U-shaped, as the space is limited and the elevation should be around 3000 mm high.

Are there any extensions or components that could help me a bit?
Otherwise, I foresee a hellishly long trial and error activity :frowning:

Well, start with what you know. Divide the floor to floor height by a suitable rise, then divide the total rise by that number to get your riser height. You will have one less tread than risers.
You can adjust the tread and run based on the space available.
Your building code may vary.


There are dynamic component stair plugins or even skp files you can use. Do a search at the extension warehouse. You should first understand the local code requirements per Shep. Usually you local code and enforcement department ie city engineers will have that info. You should ask them. Form follows function and once you have requirements then you can do some parametric studies to at least get some ideas. SketchUp Plugins | PluginStore | SketchUcation. Check and make sure these are compatible with you version of SU

If you’re in the enviable position of being able to design your own staircase (which is absolutely fantastic in my opinion),… but you don’t necessarily know a lot about doing so. . . and this is ultimately something you’ll be living with for some time to come (as in near daily exposure to it).

I offer one point of possible warning. . . Be careful about designing something in the Abstract which you don’t have a Personal Feel for.

To make up an example of what I have in mind…

If space is tight then you might be inclined to use a tread size which has a 10" run on it… and it will probably pass code. and It will look great on paper because your saving some space. . . OR perhaps you’ll eventually discover that increasing the riser height will result in the need for fewer treads ( also a space saver). . . or perhaps the size of the landing will be reduced, or the width of the treads can be shaved down some. . . and on and on.

But, the problem that I’m trying to warn you about is this. . . Make sure you know what it’s like to walk that 10" tread before you commit yourself to having one simply because it was drawn out on paper, or brought into SketchUp via a plug-in, or was a posted model in the 3D warehouse. You may very well prefer a tread depth of 11" or more.

The combination of rise and run can make a major difference in terms of how comfortable you feel when walking the stairs. Narrow treads where your heal starts to overhang the tread nosing can flat out suck, and and Riser Heights can make a staircase unenjoyable to walk on when too tall.

And so far, I’ve only been talking about the comfort level here. There is also the utility side to consider where perhaps you’ll be carrying up some stuff rather frequently. In this case landing size and position can be a godsend when properly placed. . . Or depending upon traffic the tread width will determine if more than one person can be walking on them at the same time or not.

The building codes don’t necessarily protect you from bad design. which is what I’m trying do, and I hope you see the point I’m trying to make here.

And of course whether you use that or not, is entirely up to you. I’m just trying to make the case for personalized customization, which hopefully are a pleasure to walk upon once you’re done building them.


Thanks Jim, you’re making a lot of noteworthy points here – and there even isn’t a (genuinely working) building code here in Russia to protect me from shooting myself in the foot.

That’s why I am looking at various shapes of staircases so as to ensure that tread run is at least 28 cm and rise is no more than 20 cm. However, I still have no idea how to implement this in practice and whether L-shape would be enough for that (without consuming the whole room).

Stairway design begins with thorough knowledge of applicable building codes at the location.
The parameters of the Code control the fundamental aspects of the design.

If your locality offers little code guidance, consider following the current International Residential Code.
Here’s a visual interpretation of the 2006 IRC stair code:
Stair_Code_IRC_2006.pdf (1.4 MB)

You’ll find more current versions here:
Stairbuilders and Manufacturers Association — Visual Interpretations of IRC Stair Codes

You certainly don’t need a plugin or a DC to design stairs in SU.
Modeling a stair merely requires understanding and practice with SU’s native tools.
Aidan Chopra produced three stair modeling videos, each demonstrating a different technique.

Making Stairs: The Subdivided Rectangles Method

Making Stairs: The Copied Profile Method

Making Stairs: The Treads are Components Method

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There is the old rule of thumb that says that 2 risers + one tread should equal 62…64 cm, so for a 28 cm tread a 18 cm riser would be better. For a 3 m height I would try to fit in a landing, too. A stair with straight runs is relatively straightforward to design and build, but if the space is so cramped that you need to use winding treads, it becomes more difficult to preserve comfort and safety.



In my case, the space is so strictly limited, that I will also have to use winders in the U-turn. Would you have any ideas as to how should I design them (i.e. how wide should this turn be etc)?

I don’t see how we can help you much more without knowing more about the space available.


After all is said and done, a picture is worth (well…you know). Why not show us a plan of your space as it currently exists with an indication of what it is you would like to do? With all of the talented folks who visit this forum regularly, certainly one or more of us will be able to offer cogent recommendations for a proposed layout.

Stair design is not new and if you do a internet serach 100’s if not 100’s of links will probably turn up. Once you read a few of those you will have enough information to ask a number of questions vs. a piecemeal approach and get the info to help you make a decision. A concrete design will have a much different design vs. wood approach.
Just some thoughts.

Here is my two cents. This winding stair would satisfy the Finnish code for stairs inside a single-family dwelling, with a tread of about 275 mm and a rise of about 187 mm. I adjusted the winders by eye - they might still need some tweaking. If you have space for a landing, add straight steps and squeeze 3-4 of the winders to form that.

stair_example.skp (111.1 KB)

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Your most definitely going to want to check out PlusSpec. PlusSpec has a huge range of stairs that are all parametric and easy to use. Change one part of the stairs and the whole stair case will update to suit. The PlusSpec stairs also have BIM inside of them. I have attached a GIF below for everyone to see.

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How about these that I drew for a client in SketchUp and then rendered with Shaderlight, Will they fit?

I built a mock-up for a helical staircase up to my office…
It needed to fit in the space formerly taken by a top landing [1.2x 2.2 meters]…

I made simple ‘boxes’ out of ‘intralam’ engineered timber 9 and 12 inch planks…

I stacked the boxes with added temporary legs and screwed it all together when I was happy with the spacing…

There were two brackets to the floor, one to the wall at the midpoint, and four screws into the beam at the top…

Having tested the principle, I intended to strip it down, reassemble with biscuit joints, glue and screws, then coat with epoxy resign…

15 years later, that’s still on the ‘To Do’ list…

The only plan was drawn full size on the floor, more recently I started a SU model of it… [ about 10 yrs ago ]

heres a couple of views…

the top and bottom stair haven’t been fully modelled yet…



I’m looking at purchasing Sketchup or Fusion 360. One thing I found in Fusion that I can’t find in Sketchup, is Panametric Parameters. For example, if I want to set Material = to .75", ShelfGap = 13", ShelfCount = 5 and calculate a bookshelf height as ShelfCount*(Material+ShelfGap). And say I wanted to make another bookshelf with 3 shelves, I could change the ShelfCount parameter to 3, and Sketchup would recalculate the total height.

You can do this with Dynamic Components in SketchUp (you can only create them in Pro, but can use them in Make OR Pro).

Search the 3D Warehouse for examples. There are many, including one I wrote as JohnWMcC.

There are also Ruby plugins that will create staircases (and other things) from parameters you input into a dialogue - see for example (in the Sketchucation Plugin Store )

[Edit - correction] Stair Maker, ( two different ones), Make Window, Door Maker, and Cab Maker (cabinets).

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