How Ploterr Turns a Text Prompt Into a Floor Plan

Architects have started dozens of floor plans the same way for fifty years: a blank page, a program list, and hours of manual layout before you know whether the idea even works. Ploterr's AI generation changes that first hour. Type a brief or upload a sketch, and a structured 3D BIM model — real walls, slabs, and openings — lands on the canvas ready to edit, extend, and hand forward into feasibility and documentation.

This is not image generation, and it is not a floor plan picture. It is structured geometry: every wall has a thickness and a material, every slab has an elevation and an area, every door is hosted on a wall with a real width. You can select any element, open the inspector, and edit it. You can switch to orthographic floor plan view, check dimensions, run quantity takeoff, or export to PDF — all from the first generated result.

Here is exactly how it works.

Two ways in: text and image

Text-to-CAD

Open the Ploterr Junior playground and type a brief in plain language. The brief can be as simple as "a two-bedroom apartment with an open kitchen and a south-facing living room" or as specific as "a six-storey mixed-use block with retail at ground level, 400 sqm office floors on levels 1 to 3, and residential above, with a central core."

Ploterr runs a two-phase process: preflight validation (it checks that the brief is coherent, identifies the building type, and flags ambiguities) and then generation, which builds the structured 3D model. For a floor plan you see the geometry appear on the canvas within seconds; larger site layouts take a little longer.

The generated model is immediately editable. Select a wall and change its thickness. Select a room block and adjust its dimensions in the inspector. Switch to 3D context view and check how the massing reads from the street. Nothing is locked.

Image-to-CAD

If you have a hand sketch, a reference image, a scanned napkin drawing, or an existing floor plan in any image format — upload it. Ploterr reads the spatial layout and converts it into structured BIM geometry. The conversion handles hand-drawn lines, printed plans, and photographs with varying degrees of fidelity; the clearer the source, the more precise the output.

Image-to-CAD is especially useful when a client hands you a sketch of what they want, or when you want to digitize an early concept drawing without tracing it element by element in the canvas.

Three generation modes

The AI does not use a single generation strategy for all building types. Ploterr has three modes that match how architects actually think about different scales of work.

Site mode

For multi-building layouts: urban blocks, campus schemes, mixed-use developments, transit hubs, residential clusters. Site mode understands that a site has a boundary, that buildings have setbacks, that orientation and access matter. The output includes building footprints as massing volumes on the Ploterr site canvas — placed at real latitude and longitude, against the actual map background.

From a site generation you can zoom into any building, switch to Building context, adjust storey count and height, and then descend to Level context to iterate the internal floor plan. The whole hierarchy — site, building, level — is live.

Floor mode

For single-floor plans: apartments, offices, retail spaces, educational facilities, hospitality layouts. Floor mode generates rooms with walls, doors, windows, and spatial relationships that make architectural sense — circulation zones, adjacencies, wet-area clustering.

A brief like "a 90 sqm two-bed apartment for a north-facing site, with an open-plan kitchen-dining and a separate utility room" produces a floor plan with correctly dimensioned rooms and correctly placed openings. You will still want to review and adjust — AI generation is a starting point, not a finished drawing — but the time from blank page to reviewable geometry drops from hours to minutes.

Object mode

For individual architectural elements: columns, curtain wall systems, stairs, structural frames, balcony assemblies, facade modules. Object mode is useful when you need a parametric family-equivalent to place in the canvas, or when a specific component is the subject of a generative study.

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Conversational refinement via Junior chat

Generation is not a one-shot output. After a model lands on the canvas, the Junior chat thread stays open. You can type natural-language instructions to iterate:

• "Rotate the building 15 degrees clockwise."
• "Add a mezzanine at 4.5m in the main hall."
• "Replace the single-loaded corridor with a central core."
• "Increase the office floors from 300 sqm to 450 sqm each."

Each instruction updates the canvas. The conversation history stays attached to the project so the reasoning is traceable — you can see what was tried, what was changed, and why.

This is the workflow continuity PlotAI is built around. You do not re-key geometry as the brief evolves. You refine it in conversation, and the model keeps up.

From generation to the full canvas workflow

Once a generated model is on the canvas, the rest of PlotBoard's tools are available immediately:

Quantity takeoff: wall length, area, and volume; slab area and volume; per-material rollup tables — all derived from the generated geometry automatically. If you adjust a room size, the numbers update.

Sheets: compose a professional drawing sheet (A4, A3, A2, or custom) with a viewport into the generated floor plan, add a titleblock, and export to PDF — in the same session as generation.

3D views: switch between perspective top-tilt and orthographic top-down. The Boards AI Render node can produce a photoreal visualization from any camera angle without leaving Ploterr.

Site context: if you generated a site layout, toggle on the Mapbox satellite layer and 3D OSM context buildings to see how the generated massing sits in the real neighbourhood.

	Manual setup	Ploterr AI generation
Time to first reviewable geometry	Hours to days	Minutes
Starting point	Blank canvas	Structured 3D model
Output is editable geometry	Yes	Yes
Quantity takeoff available immediately	yes (after drawing)	yes (after generation)
Works for site, floor, and object scales	Yes	Yes
Conversational refinement	No	Yes
Image-to-CAD (sketch upload)	No	Yes

What AI generation is and what it is not

AI generation is a fast first draft. It is not a finished design. Ploterr is not making architectural decisions on your behalf — it is getting structured geometry onto the canvas quickly so your time is spent on judgment, not setup.

Every generated model is a starting point. The quality of the brief shapes the quality of the output. Specific briefs (area requirements, adjacency priorities, orientation constraints) produce better starting points than vague ones. After generation, the canvas is yours — edit freely, extend with additional elements, and use the full PlotBoard tool set to carry the design forward.

The free Core tier includes one generation to get started. Ploterr Junior unlocks unlimited text-to-CAD and image-to-CAD generations across all three modes, plus the Junior chat for conversational refinement. Join the waitlist and get 25 percent off.

Early access · 25% off

Plan faster. Decide sooner.

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