As of October 2026, a 2026 North Carolina cost guide puts a mid-range 600 sq ft detached ADU in Charlotte at about $120,000 to $175,000. National guides put garage conversions at roughly $60,000 to $150,000. Plans, permits, utility work and site prep sit on top of those numbers, so the real figure comes from your lot.
What do published guides say?
We did not find an independent survey of finished ADU prices in Charlotte. The most useful published figures we found, as of October 2026:
| ADU type | Published estimate | Source |
|---|---|---|
| Backyard cottage, 600 sq ft | About $120,000 to $175,000 mid-range; about $90,000 basic to $265,000 high-end | costtobuildhouse.com, 2026 North Carolina guide, Charlotte |
| Detached ADU, national | About $110,000 to $285,000 | Angi |
| Garage conversion, national | About $60,000 to $150,000 | Angi |
| Attached ADU, national | About $100,000 to $216,000 | Angi |
| Simple conversion to custom detached, Charlotte | Around $50,000 to $150,000 or more | Henderson Properties, June 2025 |
The North Carolina guide's own Charlotte figures do not fully line up between its summary and its table, so read every number above as a rough guide, not a price.
What does that mean per square foot?
Angi's national average is about $150 to $300 per square foot, with some projects over $600. Small units run higher per square foot because the kitchen, bathroom and utility connections cost nearly the same whatever the floor area.
Is a garage conversion cheaper than a cottage?
Usually. A conversion starts with a slab, walls and a roof. A cottage needs all of those new, plus longer utility runs. A garage with a failing slab or short walls can close most of the gap.
What sits on top of construction?
- Design and engineering. Plans, structural design and the site plan.
- Permits. Town zoning fees and county building permit fees. The 2026 state law bars larger cities from charging ADUs higher permit fees from January 2027.
- Utilities. Sewer and water lines to the unit and, often, a bigger electrical service.
- Fire separation. Rated walls or floors where the ADU joins the house or sits over a garage.
- Site work. Grading, drainage, tree removal and a walkway.
Can I get help paying for it?
The City of Charlotte announced its Queen City ADU Program in September 2025 with up to $80,000 in forgivable, interest-free financing for owners who rent the unit affordably. It comes with tenant-income and rent limits. See the program guide.
Why do two Charlotte ADU quotes differ so much?
It depends on what each one includes. Ask every builder to state, line by line, whether design, engineering, permit fees, utility connections, the electrical upgrade and finish allowances are in the price. Our written, itemized quote shows each of those separately.
Related
Sources, as of October 2026: costtobuildhouse.com, "2026 North Carolina ADU Cost Guide"; Angi, "How Much Do ADUs Cost?"; Henderson Properties, "Building an ADU in Charlotte for Rental Income" (June 11, 2025); City of Charlotte, Queen City ADU Program announcement (September 24, 2025); Carolina Journal on Senate Bill 445. These numbers come from third-party publications and are not ADU Craft Charlotte pricing.
Updated October 2026