Stairs are among the hardest things to design for in tiny houses. In this article, we'll look through all the options I've found for getting into lofts and second floors, along with the regulations for how they should be built.
1. Regular stairs
This option takes up the most amount of space. That's because stairs must meet certain specifications so that they are easy and safe to climb. According to Appendix Q of the 2018 International Residential Code (IRC), stairs must have:
- Height of risers between 7 - 12 inches
- Depth of treads = 20 inches - 4/3 riser height
- Minimum width of 20 inches
- Handrails and landing platform
That's a lot of room! It could easily eat up most of your tiny house square footage. When people build full stairs into their tiny houses, it's usually combined with a space saving technique.
I've also seen clever ideas like stairs with parts that can be pulled in and out, or have a secret folding table. There are so many great ways to fully utilize the space stairs take up.
2. Spiral Stairs
Spiral stairs take up minimum horizontal space and use angled steps to climb vertically. They can look beautiful and elegant.
Spiral staircases are harder to design, build, and climb. The IRC is also picky about what makes a "proper" spiral staircase:
- Each step minimum of 26" width
- <24.5" walkline radius, or the imaginary line where a person would walk
- Tread depth >6.75" at walkline
- Riser <9.5"
- Head room >6.5'
The last bullet is going to be impossible for most tiny houses to hit. Unfortunately, spiral staircases for tiny houses are not in the 2018 IRC so you might have to make a choice between bending some code or dropping the use of a spiral staircase.
Ladders are a great alternative to stairs if you're optimizing for space. All you need is a place to store the ladder and a place to lean or hook it up to the loft. The biggest downside is that they are not as easy to climb and you would most likely need both your hands. It's probably not so bad for a space that is infrequently accessed but imagine the effort it would take to climb down in the dark to go pee.
The 2018 IRC is very friendly towards ladders:
- Rung width >12"
- 10-14" between rungs
- Able to support 200 lbs on each rung
- Installed at 70 - 80° from horizontal, makes it more stable and easier to climb
Ladders and stairs are frequently combined in tiny houses that have more than one loft. You might have stairs for one side and a ladder for the other, two ladders, or a shared ladder that's used for both lofts.
3. Alternating Stairs
We can take inspiration from boat design, which uses alternating stairs and ship ladders to save space. It takes a bit of getting use to but they are safe to use at a steep angle and you can climb hands free. How much space does it save?
That's a ton of space saved! The only thing is that alternating steps look kinda awkward but there are plenty of great examples of how to do it elegantly.
- 20" wide steps
- Tread depth >5"
- Riser height <9.5"
- Angle of descent 50 - 70° from horizontal
- Need handrails
The rules for ship ladders/alternating ladders are pretty much the same.
I think that covers most of the options, but you are only limited by your own ingenuity. There are other tactics like incorporating furniture as steps, or using a split level layout for shorter flights of stairs. I've included a few of my favorite wacky ones below.
I'd love to hear if there were other examples I missed. Leave a comment if you have any ideas.