A top-quality prebuilt staircase
takes just an hour or two for two men to install, and
it costs the contractor little more than he would pay
for materials alone.
I'm a design-builder in the high-end custom market in
coastal New England. For every house or remodel I take on, I
create a unique design, which includes the staircases.
Like a lot of builders, I used to have my own carpenters
build our custom stairs. Then one day, my neighbor Dave Cooper
invited me to check out his stair-building shop, Cooper Stairs
(which now has been bought out by Horner Millwork in Somerset,
Mass.). With a full-time staff of employees, Dave's company
does nothing but build stairs.
When I saw the details Dave was using -- precision-routed
stringers, fully housed risers and treads, glued
tongue-and-groove joinery, and so on -- I said to myself, "I'm
not giving my customers this level of quality." Though I prided
myself on my company's first-class work, I was actually doing
my customers a disservice by custom-building stairs instead of
installing the shop-built product. Then I saw what the shop was
charging for a stair package, and I realized that I couldn't
beat the price either -- certainly not for stairs of this
I employ excellent finish carpenters, but I can't expect
guys who are building a handful of staircases a year to be as
efficient or as accurate as professionals who build stairs
every day. In the shop, the materials are always on hand and
the machines and tools are set up for full-time stair building.
And a big shop has the volume buyer's advantage: In the real
world, I pay almost as much for the materials to build a stair
as the shop charges me for the finished item -- and that's
before I even look at my labor cost.
Bear in mind that there are lots of stair manufacturers
around the country. They sell stairs for every kind of house
from multifamily tracts to million-dollar palaces. I don't
suppose my supplier is unique, but I haven't shopped around
much -- you should check out your local supplier's operation if
you're seriously considering manufactured stairs.
In my market, prices look something like this (including
stairs and railings): For a straight box stair, to be placed
between two framed walls with railings attached to the walls, I
expect to pay around $900 to $1,000. That's with southern
yellow pine risers and oak treads; for basement-grade wood, you
could cut that almost in half, but to go up to poplar risers or
all oak would add a few hundred to the base price.
For a slightly nicer stair, partially open on one side, the
base price is a little more, say $1,400. Little extras like a
bullnose bottom step and railing volute would add about
If you upgrade a little more and choose stairs that are
partially open on both sides, or completely open on one side,
then you're up to around $2,000 (it's the railings that make
most of the difference). For this type of stair, poplar risers
would add almost $200, oak risers more like $400, and common
upgrade options like bullnose steps or volutes bump it up
another $400. At this level you'll get a very nice stair for a
good-quality upper-middle-market home.
Let's get a little fancier and talk about an L-shaped stair
with a landing, open on one side. Now you're looking at $2,700
for the basic stair and railings, and the various upgrades
could add another $1,300 to $1,400.
In a more upscale market, for a 90 degree curved stair,
you're in another ballpark -- $10,000 and up. You're also
looking at extra money if you want touches like over-the-post
railing transitions. On the other hand, the upgrade to all oak
is still probably under $500.
Curved stairs. We're not going to get deeply
into curved stairs in this article, but it's worth a quick
look. When Cooper's shop builds curved stairs, they output a
full-scale print of the floor plates for the curved wall from a
CAD program, and use that as a template to cut wall plates from
plywood. They send an exact duplicate of the wall plate to the
site for the framers to use, and then rig up a full-scale
replica of the wall itself in their shop (Figure 1). They build
the stairs right onto the mocked-up wall, so when the finished
item arrives on site, it drops right in place.
1. Curved stairs are built on a wall mockup that
is framed using plates cut from a full-scale CAD
pattern. Identical plates are sent to the site so the
actual wall will match the shop jig. Railings are
test-fitted in the shop before the stair is
Besides cost, another big advantage of manufactured stairs
When I started out as a builder, I thought of the schedule
in linear terms: First the foundation guys come, then the
framers come, then the plumber comes, then the hvac guy comes,
and so forth. But after years in business, I've come to think
in terms of layering: "Who can work on top of whom?" That's
because, as a rule of thumb, the longer a job takes, the less
money I make.
In the case of stairs, a prebuilt installation takes a few
hours, while building the stairs on site could tie up my best
carpenter for a week or more.
By using a shop-built component, I avoid uncertainty in both
schedules and costs. If my carpenter on site runs into a snag
on a site-built stair, the whole project stops until he's back
on track. A week can easily turn into ten days. This doesn't
just blow my cost estimate for the stair itself: By
interrupting the schedule, it also creates other costs that you
can't even account for. But when I order prebuilt stairs, it's
the supplier's responsibility to deliver them on time and on
budget. The stair package is a fixed cost that I can predict on
the first day of the job.
Here's how stairs fit into my usual time line: As soon as I
have a firm set of plans, I fax a copy to the stair shop with a
description of the stairs. They send me back a price for the
complete package, including railings, and let me know when they
can deliver. They also quote me a price to install the stairs,
but it's usually cheaper to use my own crew. I pay for an
outside installer only when my own people are tied up on
another site. When you do have a manpower problem, though, it's
nice to know your supplier can come in and do the job
The supplier won't build stairs from plans. After the house
is framed, they send a rep to the site to measure the actual
dimensions of the opening (Figure 2). It's the rep's
responsibility to make sure the stairs are built to fit.
2. Stairbuilders will quote jobs from plans, but
they generally send a field rep to the site to verify
measurements before starting work.
The time for installing the stairs is flexible. We always
build rough stairs when we frame the house so the crew and subs
don't have to use ladders to get from floor to floor. We tear
these out when the manufactured stairs arrive, which can be any
time after the roof is on, either before or after drywall.
Damage is an obvious concern. The manufactured stairs come
wrapped in protective plastic, with tread protectors tacked on.
It's pretty safe to install them early on, but I still like to
wait until most of the subs are gone -- no point in tempting
On the installation shown in this article, it worked best to
install the stairs after framing and before drywall; railings
didn't go on for another month and will be covered in a future
How the Stairs Are Built
When I saw the way the stairs were put together in the shop, I
was impressed with the efficiency as well as the quality of the
process. With every tool set up for its specific purpose and
all the materials on hand, the production process moves right
The most skilled workers handle the complicated curved
stairs, there's one man trained to run the computer-controlled
machinery that cuts and routs the stringers, and one highly
experienced woodworker hand-carves most of the custom railing
Dedicated tools make first-rate joinery possible. For
example, tread returns fit very tightly because the matching
pieces are milled on the same router using different jigs.
And although the work goes faster than it ever could on
site, the shop uses connection details that few builders
employ. Tongue-and-groove tread-riser joints are glued as well
as nailed (Figure 3).
3. Perfect-fitting tread returns are glued and
air-nailed to the treads (left). A tongue on the back
of each tread (center) matches a groove routed into the
face of each riser. Gluing and nailing these joints,
the stair builder makes up a complete set of
tread-riser pairs in about 20 minutes
Tread and riser ends are fully housed in dadoes in the
stringer, and are held snugly in place with wedges, glue, and
screws (Figure 4).
4. Stringers are precision-routed on a
computer-controlled machine. The treads are securely
wedged (left), glued (center), and screwed (right) in