Madison, WI & Dane County
Accessible ADUs.
Built right.
From day one.
Madison’s accessible home and ADU specialists. We design, permit, and build accessible housing in Dane County — with accessibility determined before design begins, documented in the contract, and built correctly the first time.
01Madison's Accessible ADU Authority
Madison's Accessible ADU Authority
If you want an Accessible ADU built right in Dane County,
If you want an Accessible ADU built right in Dane County,
there is one firm to call.
ADUs are all we build. That means we've solved the same problems — frost-depth, zero entry grades, rough-plumbing, shower pans, grab bar blocking specs — dozens of times. Not researched them… Built them.
Licensed design-build firm — ADU specialists, across Dane County
ADA scope set at feasibility check — before design begins
Every specification in the contract and construction drawings
Building Accessible ADUs all over Madison — field experience, not just research
North Side ADU — 36" clear hallways, Madison WI
02ADA Packages
Three packages — determined before design begins
Accessibility, built into any Boundless build.
Packages 01 and 02 are shown below. Package 03 is discussed at the feasibility check based on your specific situation. The package is selected before the first plan is drawn — the only point at which these decisions can be made correctly and at the right cost.
Package 01
Accessible — Essentials
The must-get-right features. Built in at construction — cannot be added later.
No-Step Entry — 0" threshold, grade-level approach
Lever Hardware Throughout — all doors and fixtures
Curbless Tile Shower with Glass Door — linear drain
Grab Bar Blocking — 2×10 at ADA heights throughout
ADA Comfort Height Toilet — 17–19"
36" Clear Doorways + Hallways
Package 02 — Full Lifecycle
Accessible — Complete
Everything in Package 01, plus the daily-living upgrades that matter for the long term.
Everything in Package 01, plus:
Non-Slip Flooring — COF ≥ 0.60 wet, flush transitions ≤¼"
ADA Bathroom Sink — knee clearance, accessible height
Side-by-Side Refrigerator/Freezer — both sections at mid-height
03
Full ADA-Ready
Maximum accessibility for wheelchair users. Discussed at feasibility check based on your specific situation.
Discuss Package 03 →
03ADA Design
Universal Design
Designed in from the start.
Designed in from the start.
Invisible when it's done right.
When accessibility is built in — not bolted on — there's nothing to explain and nothing to apologize for. It's just a well-designed home that works for everyone.
What It Looks Like
ADA features that look like nothing at all.
ADA Design Features
Six decisions. One chance to get them right.
Each of these must be built in before construction begins. Built in at design, they cost almost nothing. Retrofitted after the walls go up, they cost thousands — or can't be done at all.
Entry
Zero-Step Entry
No threshold. Grade-level approach. Requires slab elevation coordination before concrete. Wisconsin's 48" frost depth adds a drainage requirement only solvable at design.
0" thresholdBuilt in: $0–200 · Retrofitted: $8,000–15,000+
Circulation
36" Clear Doorways
ADA-standard clear width throughout. A "36-inch door" and "36 inches clear" are different. We specify clear width in every ADA contract.
36" clear, all primary doorsBuilt in: $200–400 · Retrofitted: $1,200–2,500/door
Bathroom
Curbless Shower
Bathroom floor and shower floor flush. Set at rough plumbing before the slab. Adding one later means full demolition of tile, subfloor, and drain lines.
Roll-in capable · linear drainBuilt in: $200–600 · Retrofitted: $4,000–9,000
Layout
Single-Floor Living
All functions one level. Plus 60" turning radius in the bathroom and 36" minimum hallways. Layout decisions made before walls go up.
60" turning radius in bathBuilt in: $0 — plan discipline · Cannot be added later
Hardware
Lever Hardware
Lever handles and single-lever faucets. Operable without grip strength. Critical for arthritis and tremor. Standard on every ADA build.
All doors and fixturesBuilt in: standard · Retrofitted: $50–120/door
Future-Ready
Grab Bar Blocking
Solid 2×10 blocking at ADA heights in shower walls, beside toilet, and hallways. Bars install at any future point with standard screws. $80 in lumber now vs. $2,500 later.
ADA heights throughoutBuilt in: $60–120 · Retrofitted: $800–2,500/location
04Full ADA Specification
Complete Specification
Not "ADA accessible." Specified. Documented. Built.
Every item below is either standard on our ADA builds or explicitly reviewed at design. Vague commitments don't hold up. Documented specifications do.
| Feature | Specification | Package | Why It Matters |
|---|---|---|---|
| Entry threshold | 0" | 01+ | Cannot be retrofitted without excavation and new concrete |
| Primary door clear width | 36" minimum | 01+ | ADA minimum; standard residential is 32" |
| Hallway width | 36" minimum | 01+ | Walker clearance throughout |
| Bathroom turning radius | 60" diameter clear | 01+ | Full wheelchair turn |
| Shower type | Curbless, roll-in | 01+ | Set at rough plumbing — cannot add after tile |
| Shower size | 36"×36" min (60"×30" preferred) | 01+ | 60"×30" allows caregiver assist |
| Toilet clearance | 36" clear, transfer side | 01+ | Lateral wheelchair transfer |
| Toilet height | 17"–19" comfort height | 01+ | Standard 15" is difficult with limited mobility |
| Grab bar blocking — shower | 2×10 at 33"–36" AFF | 01+ | Future bar install without tile demo |
| Grab bar blocking — toilet | 2×10, both sides | 01+ | $80 now vs. $2,000+ per side later |
| Door hardware | Lever throughout | 01+ | Operable without grip; required for arthritis |
| Faucets | Single-lever throughout | 01+ | One-hand operation |
| Flooring — bathroom | COF ≥ 0.60 wet | 02+ | LVP varies widely in wet-area traction |
| Flooring transitions | Flush or ≤¼" beveled | 02+ | Standard T-moldings are trip hazards |
| Light switches | Rocker at 42"–48" AFF | 03 | Reachable from seated; ADA standard height |
| Outlets | 24" AFF minimum | 03 | Standard 12"–18" requires significant bending |
| Kitchen counter | 34" lowered option | 03 | Standard 36" is difficult from seated |
| Knee clearance | 27"H×30"W×19"D | 03 | Seated kitchen work |
| Exterior approach | Grade + material review | All | Zero-step entry only works if approach is navigable |
AFF = above finished floor · COF = coefficient of friction
05The Lifecycle of an ADA ADU
The LifecycleThe features don't change.
The features don't change.
The people do.
The same zero-step entry and curbless shower that serve your aging parents today serve a renter thirty years from now — without a single modification. One build. Three chapters.
06ADA Tiny Homes
Small Footprint, Full Accessibility
A small ADA ADU works.
A 36-inch door is 4 inches wider than standard — imperceptible to anyone not navigating a walker, and essential to anyone who is. What does require careful layout: 60" turning radius, 36" hallways, kitchen clearances. Design decisions — addressed before the first plan is drawn.
500 sq ft, fully accessible
A well-designed 500 sq ft ADA ADU is more livable for an aging adult than a 2,000 sq ft house full of stairs. Smaller means fewer steps, less maintenance, and a home sized for how people actually live.
400–1,000 sq ft — livable, maintainable, accessible
Open plan reduces turning radius requirements
Pocket doors eliminate swing clearance in tight baths
No bathtubs — 19–21" step-over is a leading fall cause
Wisconsin winters — covered entry prevents threshold ice
07Cost Comparison
The MathBuild it once.
Build it once.
Stop paying every month.
Assisted Living — WI
$5–8K
per month. No equity. 3–5% annual increases. Most families deplete savings within 3–5 years.
Memory Care — WI
$7–12K
per month. Median annual cost over $100K. No flexibility, no family proximity.
ADA ADU — Boundless
Once
One-time investment. Adds property value. Transitions to rental when no longer needed.
ADA features cost almost nothing at construction.
Retrofit is the expensive version. Zero-step entry after the fact requires excavation. Widening a door requires full framing and finish work. A curbless shower requires complete bathroom demolition. Planned accessibility vs. unplanned retrofit: the difference can exceed $30,000.
0810 Questions to Ask Any ADA ADU Builder
Due Diligence10 questions that separate builders
10 questions that separate builders
who've done this from those who haven't.
01
How do you achieve zero-step entry on a Wisconsin lot with 48" frost depth?
Requires slab elevation and drainage strategy. Can't explain it = hasn't solved it.
⚠ "We can figure that out later"
02
What is the clear doorway width — not the door size — on your ADA builds?
A 36" door has only 33.5"–34" clear. Door size ≠ clear width.
⚠ "36-inch doors" without specifying clear width
03
At what phase do you set the shower pan elevation for a curbless shower?
Must be set before the slab. "After tiling" is the wrong answer.
⚠ "We can do that after we tile"
04
What lumber size do you use for grab bar blocking, and at what height?
2×8 or 2×10 at 33"–36" AFF. Vagueness = no documented standard.
⚠ Vague about spec or lumber size
05
What is the minimum clear floor space in your ADA bathrooms?
60" diameter. No number = no wheelchair design.
⚠ "Plenty of room" without a measurement
06
How do you handle flooring transitions in an ADA ADU?
Flush or ≤¼" beveled. T-moldings are trip hazards for canes.
⚠ "Standard T-molding transitions"
07
Can you show me an ADA ADU you've already built in Wisconsin?
Accessible design takes coordinated experience. Don't be the first project.
⚠ "We haven't built one yet but we've researched it"
08
What slip-resistance standard do you specify for bathroom flooring?
COF ≥ 0.60 wet. Most builders choose by aesthetics only.
⚠ "We'll pick something that looks nice"
09
Who assesses the site grade for the exterior approach — and when?
Before design begins. Zero-step entry on a slope requires upfront grading plan.
⚠ "We'll deal with that at site work"
10
Is the ADA scope in the contract and construction drawings?
Verbal commitments disappear. Every spec must be in the documents.
⚠ "We'll make sure to include all that"
How Boundless answers these
Grade assessed at feasibility check. ADA ADUs built in Madison. Everything in the contract. Package identified before the first plan is drawn. If it's in the contract, it's in the build.
Boundless ApproachWe design it in.
We design it in.
You don't have to ask.
Accessibility is the first design conversation. We review the site for zero-step options at the feasibility check. We select the ADA package before design begins. Everything is in the contract.
Free Feasibility Check →09Wisconsin Funding Sources
Wisconsin ResourcesWisconsin funding sources
Wisconsin funding sources
for accessible housing.
Several state and federal programs can offset the cost of an accessible ADU. Eligibility varies by income, disability status, and property type.
Federal Grant
USDA Section 504
Grants up to $10,000 for very-low-income homeowners 62+ for accessibility modifications. Loans up to $40,000 also available.
rd.usda.gov → WisconsinState Program
WHEDA Home Improvement
Below-market loans for income-eligible Wisconsin homeowners. Can be used for accessibility modifications and qualifying new construction.
wheda.com → homeownersDane County
Dane County ADRC
Connects residents to home modification programs and Medicaid waiver programs. IRIS waiver may fund modifications for eligible individuals.
dhs.wisconsin.gov/adrcState Waiver
Wisconsin IRIS / Family Care
Medicaid-funded programs covering widened doorways, ramps, and bathroom modifications for eligible individuals.
dhs.wisconsin.gov/irisFederal Tax
IRS Medical Expense Deduction
Accessibility improvements for a medical reason may be deductible when they exceed 7.5% of AGI. Consult a tax professional.
IRS Publication 502Veterans
VA Specially Adapted Housing
Veterans with qualifying disabilities may receive SAH grants up to $109,986 or SHA grants up to $22,036 (FY2024) for accessible construction.
benefits.va.gov/homeloans/adaptedhousingADA ADU construction vs. home modification
Most programs above cover modification, not new construction. An ADA ADU is new construction — which affects eligibility. USDA 504 does cover new construction in eligible rural areas. The ADRC can identify which programs apply to your situation.
10Definitions
ReferenceADA, universal design, visitability:
ADA, universal design, visitability:
not the same thing.
Federal Law
ADA
Governs commercial facilities. Does not legally apply to residential construction. "ADA ADU" means built to ADA standards — not required by law for residential.
Commercial / public — not residential
Design Philosophy
Universal Design
Making spaces usable by all ages and abilities without adaptation. Zero-step entries, lever handles, curbless showers — not medical, just good design.
All residential (voluntary)
Minimum Standard
Visitability
One zero-step entrance, 32" clear doorways, half-bath on main level. Ensures a wheelchair user can visit. No Dane County municipality currently requires it for ADUs.
New residential (voluntary in WI)
Goal
Aging in Place
Living in your own home safely as you age. An aging-in-place ADA ADU goes beyond visitability — bathrooms, kitchen, entry, circulation, hardware, future adaptability.
Long-term residential design
Wisconsin Code
Uniform Dwelling Code
Wisconsin's residential building code has no accessibility requirements for single-family construction. Accessible design only happens when someone specifically designs for it.
All new WI residential
Federal Housing Law
Fair Housing Act
Requires features in multi-family 4+ units built after 1991. Does not apply to ADUs. FHA guidelines are a useful reference for clearances and hardware standards.
Multi-family 4+ units — not ADUs
11FAQ
Frequently Asked Questions
ADA ADU questions answered directly.
Does ADA law require accessibility in Wisconsin ADUs?
No. The ADA applies to commercial facilities — not private residential. Wisconsin's Uniform Dwelling Code has no accessibility requirements for single-family construction. An ADA ADU is built to ADA standards voluntarily.
Will ADA features reduce resale value?
No — in most cases the opposite. Universal design features are considered premium in the current market. They expand the buyer pool. In Madison's ADU market, accessible rental units are underrepresented and command a premium.
Is it possible to build an ADA ADU on a sloped lot?
Yes, with site-specific planning before design begins. A zero-step entry on a sloped lot requires a graded approach at accessible grade (max 1:20 for walkways, 1:12 for ramps) and sometimes a retaining wall. We assess this at every feasibility check.
How small can a fully accessible ADA ADU be?
The practical minimum for a fully accessible one-bedroom is approximately 400–450 sq ft, assuming open-plan layout and pocket doors in the bathroom. Our typical sweet spot is 500–650 sq ft — livable and easy to maintain independently.
What's the difference between a walk-in shower and a curbless shower?
A walk-in shower still has a low curb (2–4") at entry. A curbless shower has no curb — bathroom floor and shower floor are flush. For ADA ADU design, curbless is essential. The small curb that seems trivial at 50 is a significant fall risk at 80 in wet conditions.
Can an ADA ADU also function as a rental later?
Yes — this is one of the strongest arguments for building one. Accessible units are underrepresented in Madison's rental market. Yours is ready to list without modification when family use ends.
What's the difference between "grab bar ready" and actual grab bar blocking?
"Grab bar ready" is marketing. What you need: 2×8 or 2×10 solid blocking at documented locations (shower walls, both sides of toilet, hallway) at 33"–36" AFF. Ask for this by specification in the contract, not by marketing phrase.
Does Boundless build ADA ADUs outside Madison?
Yes. We build across Dane County — Fitchburg, Middleton, Verona, Waunakee, Sun Prairie, Stoughton, McFarland, DeForest, and surrounding municipalities. The ADA packages apply across our full service area.
Related→
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More on accessible ADUs
ADUs for Aging Parents & Retirement
Why families choose ADUs over assisted living, how the finances work
Our Build Process — Feasibility to Certificate of Occupancy
5 phases, fully managed
ADU Regulations by Municipality — Dane County
Current zoning rules and feasibility scores
Ready to Start
Find out what's achievable
Find out what's achievable
on your property.
The feasibility check covers your lot, municipality zoning, site grade, and which ADA package fits your goals. 20 minutes. No commitment.