Question 1

What is an ADU (Accessory Dwelling Unit)?

Accepted Answer

An ADU (Accessory Dwelling Unit) is a secondary housing unit on a single-family residential lot. Also called a granny flat, backyard cottage, in-law suite, casita, or garage conversion. ADUs can generate rental income of $1,200–$2,500/month and increase property value by $120K–$280K.

Question 2

Do I need permit-ready plans for an ADU?

Accepted Answer

Yes — to build an ADU legally, you need permit-ready (PE-stamped) engineering plans accepted by your local building department. QuiPlans provides PE-stamped structural drawings prepared by licensed Professional Engineers in 25 U.S. states, including architectural, structural, and MEP engineering plans.

Question 3

How much does it cost to build an ADU?

Accepted Answer

ADU construction costs typically range from $80,000 to $300,000+ depending on size, location, and finishes. A studio ADU (400 sq ft) typically costs $80K–$140K. A 1-bedroom ADU (550 sq ft) costs $100K–$175K. A 2-bedroom ADU (750 sq ft) typically costs $150K–$250K. Use our ADU cost calculator for a detailed estimate.

Question 4

How long does it take to get permit-ready ADU plans?

Accepted Answer

QuiPlans delivers PE-stamped permit-ready plans in 10–14 business days. Instant downloadable architectural concept drawings are available immediately after purchase. The complete permit package including site plan, drainage, and grading takes 3–4 weeks.

Question 5

Which states do QuiPlans engineers work in?

Accepted Answer

QuiPlans licensed engineers cover 25 U.S. states: FL, TX, GA, NC, VA, MD, SC, TN, OH, MI, PA, NJ, NY, CT, MA, RI, ME, AZ, NV, CO, CA, LA, OK, NM, and DC. We are expanding to additional states.

Question 6

What's the difference between a concept plan and permit-ready plans?

Accepted Answer

A concept plan is an architectural drawing set for early planning, contractor quotes, and HOA submissions — it cannot be submitted for a building permit. PE-Stamped permit-ready plans are signed and sealed by a licensed Professional Engineer and include architectural, structural, and MEP drawings — everything your building department needs to issue a permit.

Question 7

Can I customize an ADU floor plan?

Accepted Answer

Yes. All 31 QuiPlans floor plans can be customized to your needs — modify bedroom count, bathroom layout, exterior style, square footage, and more. Customization pricing is based on square footage and complexity. Contact us for a custom quote.

Question 8

How much rental income can an ADU generate?

Accepted Answer

ADU rental income varies by location and size. A studio ADU typically generates $1,200–$1,800/month. A 1-bedroom ADU generates $1,400–$2,200/month. A 2-bedroom ADU generates $1,800–$2,500/month. In high-demand markets like California, ADUs can generate $2,500–$3,500/month.

Question 9

Do I need a feasibility study before buying plans?

Accepted Answer

If you're unsure whether your lot can support an ADU — due to zoning, setbacks, lot coverage, or utility constraints — a $349 feasibility study by a licensed engineer will give you a clear go/no-go answer before you invest in plans. The full $349 is credited toward your permit-ready package if you proceed.

Question 10

What is a garage conversion ADU?

Accepted Answer

A garage conversion ADU transforms an existing attached or detached garage into a livable dwelling unit. This is typically the most cost-effective ADU option ($50K–$120K) since the structure already exists. QuiPlans offers garage conversion floor plans and permit-ready engineering for garage conversions in 25 states.

31 PE-Stamped Building Plans

Redwood ADU

Evergreen ADU

Silvercrest ADU

Oakwood 1BR ADU

Brighton 1BR ADU

Aspen Micro Studio ADU

Cedar Compact 1BR ADU

Linden Compact 1BR ADU

Sierra Studio ADU

Harbor 1BR ADU

Brookside 1BR ADU

Mesa Micro Studio ADU

Willow 1BR ADU

Ridge Studio ADU

Sequoia 3BR ADU/Home

Canyon Studio ADU

Sycamore 3 BR Home/ADU

Redwood 2BR ADU/Home

Magnolia 4 BR Home

Cypress 4BR Home

Hemlock 5 BR Home

Spruce 4BR Home

Larch 5BR Home

Tamarack 4BR Home

Ironwood 4BR Home

Hackberry 4 BR Home

Buckeye 3 BR Home

Catalpa 3 BR Home

Highland 6 BR Home

Persimmon 5 BR Home

Basswood 3 BR Home