Alternating Tread Stairs: A Roundup
by Lloyd Alter, Toronto on 03.10.08
We love alternating tread stairs because they are such great space savers; this photo shows the comparison. So why don't we see them more often? For one thing, they don't meet a lot of building codes. Even Lapayre Stair, a big manufacturer, has an entire page devoted to telling prospective residential purchasers to get lost, noting "It is not possible to turn around on our stair. Nor can two feet be placed on the same level at the same time. It is difficult for children and the elderly to use our stair. In addition, the handrails do not meet the baluster (vertical rail) requirements for residential stairs. Children could easily fall through the rails to the ground below."
They are legal for industrial use in the USA, under international codes for mezzanines, in Canada as "secondary stairs for convenience purposes" and in the UK for access to lofts and bedrooms that do not have the only bathroom. Another source says "codes do not require stairs to unoccupied attics and lofts, so it's up to the local code inspector a ladder or stair that does not meet rise and run requirements."
It is a real shame that Lapayre won't sell their stairs to anyone, because they have a really elegant aluminum one where with a center rail and very elegant casting that ties together with the handrail. This would look great anywhere. (more pictures here)
I have climbed and descended a Karina modular alternating tread stair and it is quite an experience. It is a kit that can run straight or in spirals, with a discontinuous handrail that does not inspire confidence, but after a few uses I was quite comfortable. It is distributed by Arke, the U.S. based subsidiary of Italian spiral stair company Albini & Fontanot.
"The Karina modular space saver stairkit is a unique and stylish solution for narrow access areas, such as lofts or attics. The Karina's ingenious supporting structure allows complete flexibility in the application, and the Beachwood alternating style treads are appropriately shaped and staggered to guarantee maximum utilization of space, without compromising functionality."
Martin John Brown got an alternating tread stair approved for his wonderful tiny house in Seattle after many battles with the inspectors, but even he notes that "There’s a few caveats, though. Falls on this steep pitch could be serious, so the handrail is important. Using the handrail means you will only have one hand to carry things. And since people aren’t used to these stairs, they require PRACTICE. It might take just two or three uses to get that practice, but practice is essential. Several times I have observed a physically unfit and uncoordinated person taking their first trip down these stairs (you come down forwards just like on a regular stair), misjudging the second or third step, then stumbling a bit. They catch themselves with a hand on the handrail and then get down fine. After two or three uses they have no problem anymore. A physically coordinated person often has no stumbles at all."
So while they are a lovely space-saving idea and even legal in certain places, they are not for everyone. Still, I wish the authorities would give architects in North America a bit more leeway like they do in the UK.
See earlier Treehugger posts on the Bookcase stair (shown above) and a Czech version.. Gabriella Gustafson and Mattias Ståhlbom designed a stunning alternating tread stair that looks a little less safe and needs a handrail. See also Justin's roundup of great stairs at ::Materialicious
Thanks for the shout out, Lloyd. For the record, I'm in Portland, not Seattle. Cheers!
" It might take just two or three uses to get that practice, but practice is essential. " And how many people do you want falling down your stairs? People don't practice going up and down stairs, they go up or they go down. If you're serious about this, a cost benefit analysis is needed. The cost of more injuries and deaths against the savings. And then demonstration projects tracking the results.
"If you're serious about this, a cost benefit analysis is needed. The cost of more injuries and deaths against the savings. And then demonstration projects tracking the results."
And this is a perfect example of how we became a nation of busybody wusses. If it's not for you, don't buy them. But don't tell me how I can or can't get to the second story. It's none of your concern.
The examples show seem to have a very aggressive rise/run ratio. I could see how these would cause some trouble. As would the hard edge running up the middle of the stairs. It seems to me that a rounder curve would be a safer arrangement.
Has anyone looked at what happens with a slightly less aggressive ratio? You save less floor space, but maybe there are cases where saving only a foot or two of floor space is sufficient.
I have seen pictures of alternate-tread stairs that have ordinary rise/run ratios (the same as regular stairs), and it took several seconds of staring at the picture to figure out what was different. The most accessible picture was in a recent Terance Conran book of house details.
Maybe just throw in a mini-landing or two, or enclose them behind a half-wall with a grippable wall cap instead of a handrail. They would still be easier than either climbing a ladder or pulling down retractable attic stairs.
I agree with Jason that a less steep slope that just saves a foot or two would still be beneficial. I am also curious about the use of alternating tread stairs with a normal rise/run ratio for people (or pets) who find normal stairs too steep.
i've got several photos of lapeyre stairs in residences from books and magazines. (Dwell, Good House Cheap House, Cabins) it may be that their architects or contractors made the purchase. i imagine that homeowners could be a hassle to work with. maybe we cost more than we bring in. here's an photo of the stair in a loft featured in Dwell:
http://www.kswa.com/work/loft/
however - this 3rd party, motionsavers, sells their stairs.
http://www.motionsavers.com/Lapeyre/?gclid=CLqyu6zY7ZYCFQkiagodug2Zqw
they aren't cheap, about $1,600 but they look so cool that they become the feature of the room.
for those handy with a saw, and on a budget - Dave Osborne publishes plans to build a set yourself. And, if you subscribe to his service, he walks you through the process and helps with the math. he's code conscious.
http://daveosborne.com/dave/articles/lapeyrestairs.php
where i live, lofts aren't allowed, so i have to build mine as "furniture" - it will technically be a "bed." if i use dave's plans with some cool brushed aluminum handrails, and maybe have some aluminum treads fabricated - i can get a cool look, and a super space saving stair for a lot less.