Pick a compact outline
Filter the gallery to "Under 1,200 ft²" and look for shapes labelled "Studio or 1 bedroom". On Plus, type the exact footprint your lot and local rules allow.
ADU & guest house plans
ADU Floor Plans
for a guest house that works.
An accessory dwelling unit (ADU) is a small, self-contained home on the same lot as a main house: a backyard cottage, a guest house, a home for a parent or a rental. Design yours in Floorra from a compact outline, with its own kitchen, bathroom and living space, and check that every room is usable before you talk to a builder. Free to start.
- ≈550 ft²studio with kitchen and bath
- ≈830 ft²one bedroom with living room
- 2D + 3Dfor every plan
Accessory dwelling units
What is an ADU?
An ADU is a second, smaller home on a residential lot, with its own entrance, kitchen and bathroom. Detached ADUs are often called backyard cottages, granny flats or guest houses; attached ones are built onto the main house or into a garage.
Because ADUs are small, every square foot has to work. The usual pattern is one open room for living, dining and kitchen, a bathroom, and either a sleeping corner (a studio) or a separate bedroom. Storage and a place for a washer and dryer make the difference between a guest room and a real home.
With the room sizes Floorra plans with, a studio with a 280 ft² living space, a 170 ft² kitchen and a 50 ft² bathroom is 500 ft² of rooms, about 550–575 ft² with walls. A one-bedroom ADU with a 220 ft² bedroom and a 70 ft² bathroom instead is 740 ft² of rooms, about 810–850 ft². Choose the small room sizes to go lower.
How to design one
Design an ADU floor plan in four steps
Check your city's ADU rules for size, height and setbacks before you start.
Step 1 Step 2 Start from the Starter suite
It adds a bedroom and its bathroom. Add a kitchen and living room; leave out the bedroom for a studio.
Step 3 Lay it out
Put the kitchen and living space by the entrance and the bedroom at the back. Place rooms yourself, or let the AI architect (Plus) draw three designs.
Step 4 Check it in 3D
Add doors and windows, look around the furnished 3D cutaway, and download a free PDF to take to your designer or builder.
ADU ideas
Popular ADU layouts
Common uses and the layouts that suit them.
Studio cottage
One open room with a kitchen wall and a bathroom; the most compact option.
One-bedroom ADU
A separate bedroom behind the living space, for a tenant or family member.
Parent's suite
A step-free one-bedroom with a larger bathroom, close to the main house.
Home office studio
An office with a half bath and kitchenette, separate from family life.
Rental unit
Its own entrance, laundry and storage so it works as a long-term home.
Guest house
A bedroom, bathroom and small living space for visitors.
Who it is for
More home on the lot you have
Sketching the ADU yourself shows what fits before you pay for drawings and permits.
- Homeowners adding a rental unit
- Families planning for a parent or adult child
- Owners who want a guest house or studio
- Small builders exploring ADU layouts
Good to know
- ADU size limits, setbacks, height, parking and permits are set by your city or county and change over time; confirm them locally before designing to a size.
- Floorra designs single-storey, detached plans; units above a garage or inside an existing house are not modelled.
- Plans are concepts; a qualified professional prepares the permit and construction drawings.
How big can an ADU be?
It depends on where you live: ADU size limits are set by your city or county and often depend on the lot and the main house. Many ADU plans fall roughly between 400 and 1,200 ft², but check your local rules before choosing a size.
How small can a one-bedroom ADU be?
Using Floorra's typical room sizes, a bedroom, bathroom, kitchen and living room come to about 740 ft² of rooms, or roughly 810–850 ft² with walls. Small room sizes or a studio layout bring it down to around 550 ft².
Can I design an ADU floor plan online for free?
Yes. Choosing a gallery outline, adding rooms, placing them, 3D and the PDF download are free. On Plus you can type the exact footprint your lot allows and use the AI architect.
What should an ADU floor plan include?
A separate entrance, a kitchen, a bathroom, a living space, a place to sleep, storage and, ideally, laundry. Most local definitions of an ADU require independent cooking and sanitary facilities.
Can I use these plans to get an ADU permit?
No. They are concept plans for exploring layouts and talking to professionals. Permit drawings must be prepared by a qualified designer, architect or engineer to your local code.
Can I see my ADU in 3D?
Yes. Every plan has a live 3D model with a furnished cutaway, which helps check whether a small space feels open enough.
Free to start
Design your ADU.
A small home that works, laid out and checked before you build.