Building Zero-Step Entries for Accessible Houses

Accessible home design:  Universal access should begin at the front door

By 

Rich Kogelschatz

A few years ago, I invited a couple to my home for dinner so that we could discuss plans for the new house they wanted to build. The husband had used a wheelchair for years, ever since an automobile accident at age 18. My 20-year-old home is not barrier-free, and it was an eye-opening experience to try to help him up the front steps and then watch him navigate our narrow doors and hallways in his wheelchair. The real moment of truth came after dinner, when he asked to use the rest room. Fortunately, the door to our first-floor bath was just wide enough that I didn’t have to resort to a chain saw.
That evening taught me in a very personal way the challenges that a wheelchair user faces. I decided then and there to build homes that all of my customers could use and enjoy, regardless of their age or physical ability.

 

A Universal Need

Even though I am now a strong advocate of universal design, I don’t push the idea any harder than I push, say, pedestal sinks in half-baths. But I do try to educate my customers about the usefulness of features like zero-step entries and wide doors and halls — and I include even young and able-bodied customers in this conversation. All of us will be touched by a disability sometime during our lives. A child might be born with a disability or break a leg playing football, or a parent might become permanently disabled in an accident. Or perhaps a friend in a wheelchair will want to visit.
U.S. Census Bureau statistics support my point: 51.2 million people in the U.S. — or about 18 percent of the population — have a long-lasting disability. The Commerce Department estimates that by 2050 the number of persons worldwide aged 60 years or older will grow to almost 2 billion, and the population of older persons will be larger than the number of children for the first time in human history.

No-Step Entry

Zero-step entries are one of our most popular upgrades. With advanced planning, they’re not difficult to build, and they add only $800 to $1,500 to the overall budget, depending on the size of the home and the design of the entryway (see Figure 1). Not every client will choose this option, partly because it changes the look of the home. It seems to work better with ranch-style and other single-level homes than with multistory homes. Still, most of my customers embrace the idea. (My crew does, too, because it makes hauling tools and construction materials in and out of the house a lot easier.)

Figure 1. Raising the grade to floor level eliminates the front step, providing a smooth, rampless transition (top left, top right). To prevent water damage, the entry should have overhead protection and the porch or walkway leading up to it should be sloped for positive drainage (bottom left). The zero-step concept can also be applied to decks and outdoor living spaces (bottom right).
While it’s possible to build a zero-step entry with standard platform framing, this usually involves bringing the exterior grade up against the band joist to create a sloping entry. Careful flashing is needed to prevent insect infestation and rot.
I prefer a different approach. I place the tops of the floor joists at the same elevation as the top of the mudsill by adding height to the foundation wall and framing a bearing wall inside the basement perimeter (Figure 2). This method is more expensive, but it eliminates the need to push dirt up against the wood framing and allows me to put the entry door and garage door at the same level, creating a no-step passage between the garage and the house.

Figure 2. Increasing foundation wall heights near the entry by a foot and recessing the floor framing allow the finished grade to be raised to floor level while protecting the framing against rot (illustration, above). Instead of bearing on the sills, the joists are supported by 2x4 walls framed within the foundation walls (top left). The floor system is then framed with I-joists, whose tops are flush with the mud sill (top right). On this 2,400-square-foot house (bottom left), the additional framing and concrete work added about $850 to the budget. An ADA-compliant barrier-free threshold with a low curb completes the zero-step entry (bottom right).
A zero-step entry requires a front door with a barrier-free threshold. It’s important to slope the porch floor away from the door for good drainage. And a roof over the porch — a good idea for any main entry — is doubly important with a zero-step design.

Barrier-Free Shower

We’re often asked to build zero-step master showers. Almost everybody appreciates a curbless shower design, but it’s critical for a user with a disability.
When we’re building a tiled shower, we drop the framing under the shower floor, leaving a recess for the mortar base (Figure 3). Along the front edge of the shower, our tile contractor typically forms a low ridge of mortar, which he tiles over with the shower floor tile. Though it’s only about 1/2 inch high, this low threshold — combined with the sloped base — provides just enough protection to keep water inside the shower (Figure 4).

Figure 3. To eliminate the curb in a tiled shower, the author frames the floor with LVLs or sawn lumber rather than I-joists (top left), dropping the subfloor in the shower area about four inches (top right). This leaves room for the sloped mortar base and waterproofing membrane, which laps over the plywood subfloor at the entry by about 12 inches (middle left). Formed with mortar, a slightly ramped threshold helps contain water (middle right). For better wheelchair and walker access, the shower is fitted with double doors (bottom).

Figure 4. To build a curbless shower, the author lowers the floor framing and installs a sloped mortar bed shower base over Chloraloy, a flexible plastic waterproofing membrane. A slightly raised tile threshold helps contain water within the shower area.
Recessing the floor adds about $125 in labor and materials to the cost of a 48-inch-by-48-inch tiled shower. You’ll find that many disabled clients require showers larger than that, depending on their disability, their dominant hand, and how easily they can negotiate the transfer from wheelchair to bench. The size and design of their shower is one of the most important details to discuss with disabled clients.

Other Resources NAHB offers CAPS (Certified Aging-In-Place Specialist) training, a great source of knowledge that has increased my credibility with prospective customers. Other organizations I’ve found to be helpful are Disability Advocates of Kent County (zerostep.org), the Center for Universal Design at North Carolina State University (design.ncsu.edu/cud/), and our local chapter of the Center for Independent Living (dnmichigan.org). Also, even though the Americans with Disabilities Act (ADA; ada.gov) doesn’t apply to residential construction, it can be an important resource during the design-build process. And it’s always a good idea to have a conversation with your local building official about relevant code matters.

Sometimes the customer needs barrier-free access, but the budget doesn’t allow for a tiled shower. In those cases we use a prefabricated unit, which costs a good $2,000 less than a custom job. Most major national manufacturers offer barrier-free molded fiberglass or acrylic showers; if our client doesn’t have a specific preference, we’ve had good luck with models by Aker (akerplastics.com, 800/962-2537).
Rich Kogelschatz owns Heartland Builders, a general contractor in Rockford, Mich.