This junior ADU plan fits a self-contained studio into 450 square feet of living space on one level. The footprint measures 25'-3" × 17'-9". It has its own exterior entry, so the unit works independently from the main house, and it stays under the 500 square foot mark that defines a junior ADU.
The main room is a combined living and sleeping area at 13'-11" × 15'-9", with space for a bed, seating and a small table. Beside it, the bathroom (9'-0" × 5'-5"), the efficiency kitchen (9'-0" × 7'-6") and a closet and pantry (9'-0" × 2'-1") share the same 9'-0" width. This keeps plumbing and storage in one compact band and leaves the main room open. There is no garage and no bedroom wall, so nearly every square foot is usable.
Layout highlights
- Living and sleeping area of 13'-11" × 15'-9" holds a bed and seating together.
- Efficiency kitchen at 9'-0" × 7'-6" sits beside the main room.
- Full bathroom at 9'-0" × 5'-5" shares a 9'-0" wide service band with the kitchen.
- Closet and pantry at 9'-0" × 2'-1" adds storage without taking floor area.
- Single-level footprint of 25'-3" × 17'-9" delivers 450 sq ft with a private exterior entry.
Room sizes
| Room | Size | Area |
|---|---|---|
| Living / Sleeping Area | 13'-11" × 15'-9" | 219 sq ft |
| Bathroom | 9'-0" × 5'-5" | 48 sq ft |
| Efficiency Kitchen | 9'-0" × 7'-6" | 67 sq ft |
| Closet / Pantry | 9'-0" × 2'-1" | 19 sq ft |
Who this plan suits
This plan suits homeowners converting part of an existing house into a rental, guest suite or space for a family member. It needs a house with an exterior wall where a separate entry can be added, plus local approval for a junior ADU.
How this plan was made
It was generated in AI Architectures Plan Studio from this one-line brief: “Junior ADU (JADU) carved out of a house, under 500 sq ft: 1 bedroom-living room combined with a sleeping area, efficiency kitchen, own bath, own exterior entry, about 450 sq ft.” An AI architect drafted the room program, a layout solver placed every wall and door, and the plan was checked automatically for room sizes, circulation and daylight. The same project produced the PDF sheets, layered DXF, IFC model and 3D model you can download above.
Frequently asked questions
What are junior ADU floor plans?
Junior ADU floor plans describe a small unit of up to 500 square feet that is built within an existing house. It has its own entry, a bath and an efficiency kitchen. This plan is 450 square feet with one combined living and sleeping room.
What affects the lot and cost of building this plan?
The main drivers are how much of the existing house is converted, where the new entry goes, and the work needed to extend plumbing and electrical service to the kitchen and bath. Local rules on parking, utilities and owner occupancy also vary, so check them with your jurisdiction.
Can I change this plan by chat?
Yes. You can ask to resize rooms, move the entry, mirror the layout or adjust the width to fit your house. The plan updates from your request, and you can review the new room sizes before you download.
How do I use the PDF, DXF and IFC files?
The PDF is for reviewing the layout and sharing it with a contractor or permit office. The DXF opens in CAD software for drafting and edits. The IFC loads into BIM tools so a designer can work with the model.