Converting a conventional basement into living space is
probably the least expensive way to add useable square footage
to a home. My company, Tri-State Basement Systems, helps
homeowners realize this extra space. As specialists in basement
waterproofing and foundation repair — and as a Bilco
ScapeWel dealer and installer — we install several
ScapeWels every year.
These oversized plastic window wells provide below-grade rooms
with extra light and ventilation. Even more important, their
built-in steps allow occupants to get out of the basement and
away from the house in an emergency. For my money, installing a
ScapeWel (203/934-6363, www.bilco.com) is the easiest way to
satisfy code requirements for a second means of egress when a
basement is converted to living space.
The units come in six sizes, in depths from 48 to 62 inches and
in widths from 42 to 66 inches, measured on the inside.
Two-step models project from the house 41 inches, and
three-step models project 49 inches.
Installing a ScapeWel is a pretty straightforward process and
can usually be accomplished from start to finish in two days.
At least a week before the planned installation, I call Dig
Safe to have any underground utilities marked in the area we'll
be excavating. On the day of the dig, we bring in our compact
excavator, which we tow behind a one-ton dump truck. In the bed
of the truck we bring along a load of gravel for
While we're digging, we station a spotter to watch for anything
that might not have been identified by the utility-locating
service, such as buried cables for landscape lighting or pipes
for irrigation and site drainage (see Figure 1). An extra set
of eyes helps us avoid mishaps.
Figure 1.A second pair of eyes
helps prevent the excavator from damaging underground
utilities. The worker also provides hand signals so the
operator can get the last few bucketfuls of loose soil out of
We overdig the hole by about 2 feet, so that we have a little
extra room to work in. We also need enough space to backfill
with 12 inches of gravel on all sides, which is the amount
required by the manufacturer.
Cutting the Foundation
After digging the hole, we mark the location of the window
opening on the foundation with a lumber crayon. Our
concrete-cutting subcontractor requires that we mark the cut.
It's important that we provide a clear line for him to follow;
a bad cut can make framing the rough opening more difficult. In
areas where the foundation coating prevents us from using the
crayon, we scratch the cut location into the tar with an old
We always arrange for the concrete-cutting sub to show up in
the late morning on the first day; that way, while he's making
the cuts, we can eat lunch and prepare the header, jack studs,
and rough sill that will be installed later.
The concrete-cutter makes the cut with a pair of
hydraulic-powered saws. Since the pump that powers them runs on
gas, we don't have to supply electricity, but we do have to
provide water to control dust and cool the blade.
The cutter begins by using a conventional cutoff saw with a
16-inch diamond blade. It cuts to about 6 inches deep. Once the
blade on that saw is maxed out, he switches to a ring saw.
Without an arbor, the ring saw can cut much deeper — all
the way through a 10-inch-thick foundation from one side
Figure 2. Powered by a portable
gas-powered pump, a hydraulic cutoff saw provides smooth power
without choking the operator with exhaust fumes. The operator
first uses a cutoff saw, then switches to a ring saw to finish
the cut. Both saws require a water supply (provided by a garden
hose) to cool the blade and cut down on dust.
The sawing creates a mess on the inside of the basement as the
concrete slurry seeps through the cut, so we always warn
customers to move or protect their belongings. On this job, the
cut took about an hour. Costs for the service generally range
from $600 to $720, depending on the thickness of the
If you install a ScapeWel and decide to cut the foundation
opening yourself, it's important to make the horizontal cuts
first and then the vertical cuts, so the blade doesn't get
Once the cuts are made, we pull the pieces out of the hole with
the excavator (Figure 3).
Figure 3. Cutting the 4-foot-square chunk
of concrete into four pieces makes it easier to handle. One
piece fell inside the basement; it was lifted out with a chain
attached to the excavator's bucket.
Installing the ScapeWel
Next we prepare the opening. We start by bringing in the
four-ply header. Four pressure-treated 2x8s combined with four
1/2-inch layers of treated plywood match the thickness of the
foundation pretty closely. For the jack studs and rough sills
we use PT 2x8s, secured with Tapcons and urethane construction
adhesive (Figure 4).
Figure 4. Concrete screws and a heavy dose
of urethane construction adhesive are used to fasten the jack
studs to the opening. Cutting the jack studs a little long and
beating them into place ensured the header was carrying the
load from above.
In accordance with the manufacturer's dimensions, we mount the
side panels of the ScapeWel to the foundation, making sure
they're plumb. We use 1/4-inch galvanized wedge anchors spaced
about every foot (Figure 5).
Figure 5. The ScapeWel sides should be
placed at least 4 inches above grade to prevent debris (and
people) from falling inside. The sides are fastened to the
foundation with 1/4-inch wedge anchors. The flange can also be
mounted directly to a metal window buck; it contains two hole
patterns for different brands of basement windows.
Once the sides are mounted, we install the step sections that
form the back of the well. The step panels snap onto the sides
and are fastened with deck screws. We make sure the well is
square, then run in 2 1/2-inch deck screws with a cordless
drill (Figure 6).
Figure 6. Before securing the step panels,
workers check that the unit is square by taking diagonal
measurements. Then they secure step panels to each side with a
pair of 2 1/2-inch coated deck screws.
Once the well is assembled and braced, we start backfilling.
The manufacturer's instructions suggest backfilling by hand,
but we've never had any problems using the machine. Our
operator is careful to backfill around the well evenly and in
small lifts (Figure 7).
Figure 7. The manufacturer requires that
the ScapeWel be backfilled with gravel; this reduces soil
pressure that could distort the molded plastic. Prior to
backfilling, the unit must be braced with 2x4s or 2x6s to
While we were excavating the site shown on these pages, it
became clear that the clay soil wouldn't drain very well
— if at all — and we grew concerned that the new
window well might fill with water. So we went looking for a
functioning foundation drain that could handle any groundwater
or seepage that found its way into the bottom of the well. When
we didn't find one on the outside of the building, the GC
— who'd worked on other homes in the area —
suggested that we check under the basement slab, where we did
in fact find a functioning footing drain.
Our next problem was how to connect an exterior drain in the
bottom of the well to that interior footing drain. In
situations like this one, our expertise in basement
waterproofing comes in handy.
After drilling through the foundation wall in two places with a
2 1/2-inch core bit, we installed a pair of 2-inch T-shaped
drains that connect to a special hat-shaped pipe over the
holes. The flat pipe runs into the footing drain, and the floor
is patched with bagged sand mix (Figure 8).
Figure 8.Installed at the base
of the well, T-shaped drains (middle) prevent water from
accumulating in the bottom of the well. They're run through
holes in the foundation and dump water into 1/2-inch-thick flat
piping on the inside of the foundation wall (top). More
commonly used to collect seepage from foundation cracks, the
flat piping is easier than conventional pipe to hide behind
furred walls; it channels water into a foundation drain located
under the basement slab. Once the pipe is routed into the
drain, the floor is patched with sand mix (bottom).
The pipe, which is more commonly used for controlling seepage
through foundation cracks, is only 1/2 inch thick, so it can be
covered or hidden more easily than round pipe.
Installing the Window
With the ScapeWel backfilled and the drainage system in place,
we can install the window in the opening. We use an all-vinyl
sliding unit. Given the proximity to grade and the
high-humidity environment, we think vinyl is a smart choice.
And we use sliders because they're easy for children to operate
and don't rely on a mechanical balance system that can fail or
become less effective over time.
We caulk the nailing fin per the manufacturer's instructions
and plumb the window, then fasten it with 13/4-inch roofing
nails. In the project shown, trimming out the window was not
part of our contract; it would be handled by the GC.
When we do trim the window, we install self-adhering flashing
over the nailing fins and use cellular PVC trim. We like the
plastic trim because there's no ongoing maintenance and no
chance for rot.
The final step is to install the acrylic cover. Small metal
clips hold the cover in place while allowing it to be easily
opened in the event of an emergency (Figure 9). The
manufacturer also offers a sturdy steel cover that can be used
in locations where there's a good chance someone could fall
into the well, or where it's required by code.
Figure 9. A clear plastic cover prevents
debris and animals from getting inside the ScapeWel. Metal
clips keep it in place in high winds but allow it to be easily
opened from inside. For greater protection, a grated steel
cover is available.
We charge $4,500 to install a 54-inch three-step ScapeWel like
the one shown.
Scott Anderson owns Tri-State Basement Systems
in Berlin, Vt.