"Granny flat" and ADU mean the same thing in California
In California state law and city ordinances, what older homeowners call a "granny flat" is exactly the same as an Accessory Dwelling Unit (ADU). The terminology is colloquial, the building category is regulated. Anyone advertising as a "granny flat builder" should also be a licensed ADU contractor.
What homeowners typically want when they say "granny flat"
- A small, single-story unit (350–650 sf)
- An aging-in-place layout — no stairs, wider doorways, walk-in shower
- Built close to or attached to the main house for caregiver convenience
- Built quickly because the family need is immediate
Vision ADU specializes in these "aging-in-place" ADUs across LA County, Orange County, and the Inland Empire.
Average granny flat pricing in 2026
| Size | Detached | Garage Conversion | Attached/JADU |
|---|---|---|---|
| Studio (350–450 sf) | Property-specific written estimate | Property-specific written estimate | Property-specific written estimate |
| 1-bedroom (500–650 sf) | Property-specific written estimate | Property-specific written estimate | Property-specific written estimate |
Aging-in-place features (zero-threshold shower, grab bar blocking, lever handles) affect the scope and should be included in the property-specific written estimate; they support safety and dignity..
How to vet a granny flat builder
The same criteria as any ADU builder, with three extras:
- Universal-design experience — ask to see at least one completed unit with full aging-in-place specs.
- Knowledge of city-specific JADU rules if you want the unit attached to the main home — Junior ADUs have separate setback and kitchen rules.
- Sensitive timeline management — granny flat projects often have family pressure. Confirm the builder can hold a firm completion date.
Why the Vision ADU process fits granny flat projects
- Free site evaluation typically scheduled within 5 business days
- Architectural plans drafted in-house — fewer back-and-forth weeks
- Single point of contact for the whole project
- Documented average 4–6 months permit-to-keys for detached units
Book a free granny flat consultation or browse our service areas.
Frequently Asked Questions
Is a granny flat the same as an ADU?
Yes. In California's legal and permitting systems, "granny flat," "casita," "in-law unit," and "Accessory Dwelling Unit (ADU)" all refer to the same category.
How much does a granny flat cost in California in 2026?
Detached studio granny flats require a property-specific written estimate all-in. One-bedroom granny flats require a property-specific written estimate all-in. Garage-conversion granny flats require a property-specific written estimate.
Can a granny flat be attached to my main house?
Yes — those are called Attached ADUs or Junior ADUs (JADUs), depending on size and kitchen configuration. Both are legal under state law.
How long does a granny flat take to build?
4–6 months for detached new construction, 3–4 months for garage conversions. Add 2–3 months upfront for design and permits.
Can my granny flat be rented out later?
Yes — California law allows ADUs to be rented for 30 days or more. Many homeowners use the granny flat first for family, then rent it later for income.
Related Vision ADU Resources
- How Much Does an ADU Cost in California in 2026? (Full Breakdown)
- 1,200 sq ft ADU Cost Breakdown in California (2026 Pricing)
- ADU Financing Options in California (2026 Lender Guide)
- ADU Permit Guide: Los Angeles 2026 (Complete Step-by-Step)
- ADU Contractor in Glendale
- ADU Contractor in Riverside
- Los Angeles County ADU Builder
- Orange County ADU Builder
- Inland Empire ADU Builder
- 2026 ADU Cost Calculator
- All Vision ADU Service Areas