Two detached ADUs in the Santa Clarita area will often cost about $360,000 to $560,000 or more combined, and two 1-bedroom rentals at today’s rents bring in about $4,400 a month. If you finance the whole project at current rates, the rent often only covers the payment, taxes, and insurance. Two ADUs make the most sense with cash down, tight cost control, or family members who need the housing.
AB 956 allows two detached ADUs on a single-family lot starting January 1, 2027. Here’s how to judge whether it’s worth it on your lot.
What do two ADUs cost?
| Combination | Typical combined cost |
|---|---|
| Two detached ADUs, 600 to 800 sq ft each | about $360,000 to $560,000+ |
| One detached ADU plus a garage conversion | about $250,000 to $500,000 |
| Two prefab ADUs, installed | about $240,000 to $640,000 |
These ranges combine the single-unit ranges in our ADU cost guide. Building both at once can save on design, permitting, and shared utility trenching, but get that confirmed in your bids.
What can two ADUs rent for?
In August 2026, Rentometer reported Santa Clarita averages of about $2,190 a month for a 1-bedroom and $2,740 for a 2-bedroom, across property types.
| Scenario | Monthly rent | Yearly gross |
|---|---|---|
| Two 1-bedroom ADUs | about $4,400 | about $52,800 |
| Two 2-bedroom ADUs | about $5,500 | about $66,000 |
| One of each | about $4,900 | about $59,000 |
Does the math work?
Here’s an example with stated assumptions. Your numbers will differ.
- Project: two 1-bedroom detached ADUs, $400,000 total, fully financed.
- Loan payment: at 7.5%, about $2,800 a month over 30 years, or about $3,220 over 20 years.
- Property tax and insurance: roughly $450 to $550 a month on the added value.
- New monthly cost: roughly $3,250 to $3,770.
- Rent after a 15% vacancy and maintenance reserve: $4,400 x 0.85 = about $3,740.
In this example, the units come out a few hundred dollars a month ahead on a 30-year loan and about break-even on a 20-year loan, before income taxes. The picture improves with cash down, a lower build cost, or higher rents, and long-term appreciation and loan paydown add value over time.
The break-even test: combined rent x 0.85 should exceed the new monthly payment plus taxes and insurance. If it doesn’t, the project depends on appreciation.
How do people finance two ADUs?
- HELOC or home equity loan: works with deep equity, but $400,000 or more takes a lot of it.
- Construction or renovation loan: draws as work is completed, sometimes based on after-project value.
- Cash-out refinance: usually expensive if you’d give up a low existing rate.
- Phasing: build one ADU now and the second later, using the first unit’s rent to help.
Some lenders can count projected ADU rental income, within limits. See financing an ADU in Santa Clarita.
When do two ADUs not make sense?
- Small lots, where two units would feel cramped and rent for less
- Thin cash flow, where an overrun or a vacancy would hurt
- No interest in being a landlord, unless you budget for a property manager
- Septic limits in Acton and Agua Dulce, which may cap the number of bedrooms
What about family instead of rent?
Not every two-ADU project is about income. One unit for aging parents and one for an adult child, with the main house for you, can make sense even when the rental math is thin. The value is in keeping family close with separate front doors.
Want a real price for your lot?
Call (661) 486-8393. If no one answers, leave a voicemail with your name, phone number, address, and the type of ADU you want. You can also use the contact form. We’ll pass your details to a local ADU contractor, who will follow up with you directly. There’s no obligation to hire.
Two-ADU FAQs
When can I build two detached ADUs?
Under AB 956, starting January 1, 2027. Today you can combine one detached ADU with a converted ADU and a JADU.
Is it cheaper to build two ADUs at the same time?
Often, because design, permitting, mobilization, and trenching can be shared. Ask each bidder to price both options.
Do I need a property manager for two ADUs?
Not necessarily, but managing two tenants takes time. Professional management commonly costs a percentage of the rent.
How do I run the numbers for my lot?
Start with real bids, local rent comps, and a lender’s rate quote. Then apply the break-even test above.