+ PROMPTS TO COPY
ChatGPT floor plan prompts you can copy
These prompts are for ChatGPT itself, before you draw anything. Use them to turn a wish list into a clear plan brief, then take that brief into a CAD tool to make the actual drawing. Replace the bracketed parts with your own details.
How to use these prompts
These are prompts for the planning you do in ChatGPT before any drawing. A few habits make them work better:
- Keep one conversation per project, so ChatGPT has your brief as you go.
- Replace every bracket with your own details. Real numbers get useful answers.
- Ask for words and tables, not images. A picture of a floor plan is hard to measure and can’t be edited.
- Make it show its work. Ask it to total the square footage and to label guesses as assumptions.
- Check what matters. ChatGPT can make mistakes, especially with math and local rules. Here’s what ChatGPT can and can’t do with floor plans.
House plan prompts: start with the brief
A good brief keeps every later answer grounded in your real project. Start by letting ChatGPT ask the questions.
I’m planning a [single-story house] on [a 1-acre rural lot] in [county, state]. Before suggesting anything, interview me about the plan. Ask one question at a time about who will live there, how we use the house day to day, must-have rooms, the size limit, the site and views, and anything that must stay fixed. After about ten questions, summarize my answers as a one-page plan brief.
If you already have notes, skip the interview and have ChatGPT organize them:
Here are my notes for a [small cabin]: [paste your notes]. Turn them into a plan brief with these headings: goals, household, must-have rooms, nice-to-have rooms, size limit, site notes and open questions. Label anything you inferred as an assumption instead of stating it as fact.
What to check: the brief says what you meant, and nothing you didn’t say appears as a fact.
Prompts for room sizes and square footage
Next, turn the brief into a room program: every space with a size, and a total you can compare with your limit.
Using the brief above, list every room and space with a target size in feet (width by length) and its square footage. Include halls, closets and a mechanical space, and add a line for walls and circulation. Put it in a table, total it, and compare the total with my [1,400 square foot] limit. Show your math.
My house has to fit inside a [32 by 44 foot] rectangle. Check whether this room program fits. If it doesn’t, suggest three ways to make it fit, such as smaller rooms, combined spaces or a loft, and say what each option gives up.
What to check: add up the table yourself. The rooms should make sense for your furniture and how you live.
Floor plan design prompts: layout and flow
Now work out where things go, still in words. Describing a layout makes the reasoning visible, so you can argue with it.
For this room program, list which rooms should be next to each other, which should be close, and which should be kept apart, with one short reason for each. Group the rooms into zones such as public, private and service. Keep the plumbing rooms together where it makes sense.
Describe two layout options for this program in words, not as an image. For each one, say where each room sits in the footprint (for example, the northwest corner), which walls get the doors and windows, and where you enter the house. Then compare the options on privacy, daylight, noise and plumbing runs.
Walk me through option [A] as if I were carrying groceries in from the car, then as if I were getting up at night to use the bathroom. Point out long hallways, rooms I have to cross to reach other rooms, doors that would collide, and places where furniture would block the path.
What to check: picture yourself living in each option. Your own routines matter more than any rule of thumb.
Prompts for revising the plan
Change one thing at a time, and say what has to stay put. That keeps the plan from drifting.
Change one thing in option [A]: [move the laundry next to the back door]. Keep the footprint, the bedrooms and the kitchen where they are. Tell me what else has to move because of this change, then give me the updated room list with sizes.
What to check: the fixed rooms really stayed fixed, and the new total still fits your limit.
A prompt for a permit sheet list
ChatGPT can help you get organized for the permit office, as long as you treat its answer as a starting point.
I plan to apply for a building permit for [a new 1,200 square foot house] in [county, state]. List the drawings a permit set for a project like this commonly includes and what each sheet usually shows. Then write the questions I should ask my building department to confirm what they actually require. Do not guess at local code requirements; mark anything I need to confirm.
What to check: compare the list with your building department’s own checklist. They have the final say. The building permit drawings checklist is a good second reference.
A prompt to hand the plan to a CAD tool
Last, ask ChatGPT to package everything you decided into a drafting brief. This is what you carry into a drawing program.
Summarize our final plan as a drafting brief I can give to a CAD tool. Include the units, the overall exterior dimensions, each room with its size and position in the footprint, every door and window with its wall and approximate size, anything that must stay fixed, and a list of open questions. Use plain lists, no images.
What to check: every size matches the room program you approved, and the open questions are ones you can answer.
Turn the result into a real drawing
With the drafting brief ready, it’s time to draw. You can do that in any CAD program. AI CAD PRO is one option: free floor plan software for Windows whose assistant, Astra, runs on your own ChatGPT subscription (Settings, then Sign in with ChatGPT) or an OpenAI API key billed by OpenAI.
Paste the brief into Astra’s chat in a new project. It draws walls, rooms, doors, windows and dimensions as editable 2D CAD objects, so you can check each one and change it by asking or by hand. For prompts to use inside the app, see what to ask Astra.
From there, add a site plan, elevations and an electrical plan in the same project, and preview each sheet as it will print. The app has drafting checks, but it can’t tell you whether your plan meets code. Your building department decides that.
GOOD QUESTIONS
Questions, answered.
What is a good ChatGPT prompt for a house plan?
One that gives ChatGPT your real constraints, like who will live there, the size limit, the site and what must stay fixed, then asks for a room list with sizes, the math and its assumptions. Asking it to interview you first is an easy way to start.
Is there a ChatGPT floor plan generator prompt?
You can ask ChatGPT for a floor plan image, but you get a picture you can’t measure or edit. Prompts that produce a room program and a drafting brief are more useful, because you can draw from them in a CAD tool.
How do I get ChatGPT to use my exact dimensions?
State the units, list the fixed dimensions, and ask it to repeat them back before it suggests anything. Then ask it to total the room sizes and flag anything that doesn’t fit.
Can ChatGPT tell me what my building department requires?
It can tell you what permit sets commonly include and help you write your questions. Only your local building department can say what it requires for your project.
FREE FOR WINDOWS
Take your plan from prompt to drawing.
Download AI CAD PRO for Windows, sign in with ChatGPT in Settings, and paste in your drafting brief. It’s free to download and free to use.
Windows 64-bit · Works with your ChatGPT subscription