ADU design: a custom ADU floor plan for your backyard, drawn by AI

Planning an ADU starts with one question: what fits on your lot? Tell Plan Chat the space you have (“22 × 30 ft behind the garage”), the size you are allowed and the rooms you want, or start from one of 27 measured ADU plans from 310 to 1,213 sq ft. The AI drafter draws the ADU floor plan as CAD with walls, doors, windows, kitchen and bath fixtures, dimensions and room areas, and changes it by chat until it works. Take the PDF to your designer, builder or city pre-application meeting.

Open the CAD studio See drawings made with it →

Some new accounts get their first drawing free while we test it.

CAD floor plan drawn by the AI drafter: structural grid, hatched walls, doors with swings, dimension chains, room tags with areas, room schedule and legend — A family house, 12 × 10 m, drawn from a short brief in about three minutes. Watch it being drawn.

How it works

1. Give it your constraints
Available footprint, maximum size, bedrooms and baths, entry side, anything the city told you (height, setbacks) as notes.
2. Get a measured plan
The drafter lays out the ADU on a grid with real wall thicknesses, kitchen and bath fixtures, door swings, windows, dimension chains and room areas.
3. Change it, then hand it over
“Make the bedroom 11 ft wide”, “move the entry to the long side”, “add a porch”. Download PDF, DWG or DXF for whoever prepares the permit set.

Real drawings: adu design in practice

All community drawings →

Fits your footprint

You give the space; the plan is drawn to it, with the total area in the room schedule so you can check it against your limit.

Starts from tested layouts

27 measured ADU plans (studio, junior ADU, garage conversion, 1, 2 and 3 bedrooms, 2-story) can be opened and changed instead of starting blank.

3D and renders included

See the ADU in 3D from the same walls and openings and order a photoreal render to show family, a lender or neighbours.

What you get

DXF	Layered, opens in AutoCAD, BricsCAD, DraftSight, LibreCAD, QCAD, Rhino, SketchUp (import) and Revit (link).
DWG	AutoCAD 2010 format, so every AutoCAD from 2010 on and most DWG-compatible programs open it.
PDF	A3 landscape sheet plotted to a true scale (1:50, 1:100 …) with a border and a title block.

Plus a 3D model built from the same walls and openings, photoreal renders of any version, and every version kept with its own link.

Layers in the drawing

A-WALL	walls, with A-WALL-PATT for the cut hatch
A-DOOR / A-GLAZ	doors with swings, windows
A-GRID	structural grid with bubbles (A, B, C … / 1, 2, 3 …)
A-ANNO-DIMS	dimension chains, overall and per bay
A-ANNO-TEXT	room names, numbers and areas, room schedule
A-FURN / A-FLOR-FIXT	furniture, kitchen and bathroom fixtures
A-FLOR-STRS / A-SITE / A-PLNT	stairs, site elements, trees

Tips for the best result

Measure the free space on the lot and subtract your local setbacks before you start.
Say whether it is detached, attached or a garage conversion.
Ask for the total area in sq ft so you can compare it with your city’s ADU size limit.
Check local ADU rules (size, height, parking, setbacks) with your city; the drafter does not know them.

Start from a measured ADU plan

Questions

How do I design my own ADU?

Measure the space on your lot, check your city’s ADU limits, then describe the ADU (size, bedrooms, entry side) in Plan Chat or open one of the measured ADU plans and change it by chat. The AI drafter draws a dimensioned floor plan you can download as PDF, DWG or DXF.

Can AI design an ADU floor plan?

Yes, as a concept: Plan Chat drafts a measured ADU floor plan that fits the footprint and rooms you give it, and revises it in seconds. It does not check zoning, structure or energy code; a licensed designer or architect prepares the permit drawings.

Do I still need an architect for an ADU?

For the permit set, usually yes, or a licensed designer, depending on your city. Coming with a measured plan you already like saves rounds and fees, and the DWG/DXF gives them a starting file.

Can it do a garage conversion ADU?

Yes. Upload a photo or sketch of the garage with its inside dimensions, or start from the 20 × 20 ft garage conversion plan, and describe the layout you want.

What does it cost?

Plans from $12 a month (AI Architectures credits). A new ADU plan usually uses 700 to 1,800 credits and each change 60 to 600; PDF, DWG and DXF downloads are included.

Try it with your own plan

Drawings, changes and renders use credits from an AI Architectures plan, from $12 a month; DXF, DWG and PDF downloads are included. See pricing.

Open the CAD studio

More ways to use Plan Chat

AI concept drawings can contain mistakes: check dimensions and have a licensed architect or engineer review a plan before you build or apply for a permit. Plan Chat is part of AI Architectures by 20Vision: 500,000+ hours of drafting, modelling & rendering saved, 280 years of full-time work our users got back, across 80,000+ designs.