One Property, Two Households
A modular ADU lets you house aging parents, adult children, or a caregiver — close enough for family, separate enough for independence — or rent it out for income that pays off the build. Run your numbers below.
Quick Answer
An ADU is the most cost-effective way to house aging parents, adult children, or a live-in caregiver on property you already own — or to earn $900–$1,800/month in rent. A SaltGrass modular ADU runs $75K–$155K all-in versus roughly $5,000–$6,000/month for assisted living or $1,400–$2,000/month to rent separately. Built rental-ready from day one, every unit can convert to income later and adds ~20–30% to property value.
Housing Costs Made This a Family Problem
Home prices and rents have climbed faster than wages across the country. Buying a second home isn't realistic for most families, assisted living runs thousands a month, and a separate rental can eat half of a young worker's paycheck. So aging parents stay alone in homes they can't maintain, and adult children move back into childhood bedrooms.
An ADU on your existing property changes the math. The mortgage already exists. The land is paid for. Adding a fully separate 320–960 SF modular unit creates a second household for a fraction of what buying or renting separately would cost — and SaltGrass builds it in the factory, so the cost and timeline stay predictable.
Three Ways Families Use a SaltGrass ADU
Aging Parents Moving In
Keep Mom or Dad close without sending them to a facility. Full independence — their own kitchen, bath, and entrance — with family steps away. A modular ADU pays for itself in a few years versus assisted living, and you keep the asset.
We design these accessible from day one: single-level layout, no-step entry, 32"+ doorways, walk-in shower with grab bars, accessible counter heights. Retrofitting later costs 2–3×.
Adult Children Building Independence
A working adult child who can't yet afford their own place gets a real address and full privacy without consuming half their paycheck — while they save for a down payment.
When they move out, the unit becomes a rental that covers its own financing and adds 20–30% to your property value — it pays for itself twice.
Live-In Caregiver
House a live-in caregiver for an elderly or disabled family member in their own dignified space. Privacy dramatically improves caregiver retention and quality of care versus a spare bedroom.
Design priorities: a separate entrance, sound insulation, independent climate control, and a dedicated parking spot.
Run the Numbers on Your ADU
See how rental income offsets — or fully pays off — your build. Tap a model to start, then adjust to match your market.
ADU Earnings Calculator
Plug in your numbers and see how rental income pays off a SaltGrass ADU.
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Enter your home value, ADU cost, and expected rent (or tap a model above).
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~25% (FHFA avg)
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* Principal & interest at the selected rate and term. Property-value estimate uses the FHFA-cited 20–30% average lift for ADU properties. Excludes taxes, insurance, maintenance, and vacancy. Rents and ADU rules vary by market — we'll help you find the right numbers for your property.
How an ADU Compares
| Option | Upfront | Ongoing | 10-Year Picture |
|---|---|---|---|
| SaltGrass ADU for a family member | $75K–$155K | ~$150–$250/mo utilities | Asset retained + ~20–30% value lift |
| Assisted living (national avg) | $0 | ~$5,000–$6,000/mo | $600K+ sunk cost |
| Family member rents separately | deposit | ~$1,400–$2,000/mo | $170K–$240K sunk cost |
| SaltGrass ADU as a rental | $75K–$155K | earns $900–$1,800/mo | Often pays off the build + adds value |
National averages for comparison; assisted-living and rent figures vary by region. "Asset retained" means the ADU is still on your property at year 10, adding value and able to generate rental income. ADU rules vary by jurisdiction — we confirm what your lot allows during Feasibility.
How We Design ADUs for Family
An ADU built for a loved one has different priorities than one built purely for rental. Our defaults for multi-generational projects:
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✓ Accessibility first
Single-level, no-step entry, 32"+ doorways, walk-in shower with grab bars, accessible counter heights — built in from day one.
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✓ A real, separate entrance
Your family member has their own door and mailing address — dignity matters, not a basement room.
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✓ Sound insulation & independent climate
Privacy between the homes and a mini-split so each household sets its own temperature.
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✓ Rental-ready from day one
Fully code-compliant as a separate unit, so it converts to income the day a family member moves on — no rework.
ADU & Multi-Gen FAQs
What is an ADU, and why build one?
An ADU (Accessory Dwelling Unit) is a fully separate living space — its own kitchen, bathroom, and entrance — added to a property you already own. Families build them for two reasons: to house a family member (aging parent, adult child, or caregiver) close by but independent, or to generate rental / Airbnb income. Because the land and primary mortgage already exist, an ADU creates a second household for a fraction of what a second home or a separate rental would cost.
How much does a SaltGrass ADU cost?
Our modular ADUs start around $75,000 for a 320 SF studio, $105,000 for a 640 SF 1-bedroom, and $155,000 for a 960 SF 2-bedroom — all-in (fabrication, delivery, and installation). Final pricing depends on finishes, site conditions, and utility tie-ins. Factory construction keeps the cost and timeline predictable versus a stick-built addition.
How does an ADU pay for itself through rent?
A long-term rental ADU typically earns $900–$1,800/month depending on your market; short-term (Airbnb) can run higher with more management. Use the calculator on this page to model your exact numbers — rent minus the loan payment is your monthly cash flow, and applying the rent to principal can pay the build off years early. ADUs also add roughly 20–30% to property value (per FHFA research), so you build equity on top of the income.
Is an ADU a good option for aging parents?
It is one of the most-requested use cases we see. An ADU lets a parent live on the family property with full independence — their own kitchen, bath, and entrance — while family is steps away for daily check-ins and emergencies. Compared to assisted living (a national average of roughly $5,000–$6,000/month), a one-time ADU build pays for itself in just a few years, keeps the family together, and you still own the asset afterward. We design these units accessible from day one (single-level, no-step entry, wider doorways, walk-in shower).
Can the ADU become a rental later if my family member moves out?
Yes — every SaltGrass ADU is built as a fully code-compliant, rental-ready unit from day one (separate kitchen, bath, and entrance). When an aging parent transitions or an adult child buys their own place, the ADU converts to a long-term or short-term rental with no modifications, generating income that often covers the original build financing.
Are ADUs allowed where I live?
ADU rules vary by city and state, and many states have recently expanded ADU rights to address housing shortages. We build and deliver across the USA and help you understand your local requirements (size limits, setbacks, parking, utility connections) before you commit. The Feasibility step confirms what your specific lot and jurisdiction allow.
Thinking About an ADU for Your Family?
Tell us who'll live in it and where — we'll help you size it, price it, and run the rental numbers.