How to Redesign a Room With Nano Banana

What "Nano Banana" actually is

"Nano Banana" is the nickname for Google's Gemini image generation and editing model. It became popular because it's genuinely good at one specific thing: editing an existing photo while keeping the parts you didn't ask it to change. That makes it a natural fit for interior design, where the whole point is to reimagine a room you already have rather than dream up a generic stock photo. If you feed it a picture of your living room and ask it to swap the sofa and repaint the walls, it tends to preserve the window placement, the ceiling height, and the general bones of the space.

This tutorial walks through how to redesign a room with Nano Banana from scratch, including prompts you can copy, then gives you an honest rundown of where it shines and where it gets frustrating. Full disclosure up front: this is the same family of model that powers our own app, so we know its strengths and its rough edges well. We'll get to the app later. First, the actual how-to.

What you need before you start

You need three things: a clear photo of the room, access to a Gemini-powered tool that can edit images (the Gemini app or Google's AI Studio are the usual entry points), and a rough idea of the look you want. The photo matters more than people expect. Shoot in daylight if you can, hold the phone level, and capture as much of the room as possible in one frame. A dim, cluttered, or tightly cropped photo gives the model less to work with and leads to weirder results.

Step 1: Upload your room photo

Open your Gemini-based tool of choice and attach the photo. You're not generating from nothing here; you're handing the model a starting image and asking it to transform it. This image-to-image approach is what keeps the structure of your room intact instead of inventing a brand-new floor plan.

Step 2: Write a clear, specific edit prompt

The single biggest factor in your result is the prompt. Vague prompts ("make this nicer") produce vague, generic rooms. Specific prompts produce usable redesigns. Name the style, the key furniture, the colors, and the mood. Here are example prompts you can adapt:

• For a living room: "Redesign this living room in a warm Scandinavian style. Light oak floors, a low cream linen sofa, a small round wooden coffee table, soft natural daylight, a few green plants. Keep the existing windows and room layout."
• For a bedroom: "Reimagine this bedroom as cozy modern minimalist. Neutral beige and white palette, low platform bed with textured bedding, warm bedside lighting, no clutter. Preserve the window and ceiling."
• For a kitchen: "Update this kitchen to a modern farmhouse look. Matte white shaker cabinets, butcher-block countertops, black hardware, a subway-tile backsplash. Keep the existing window and appliance positions."

Notice the pattern: style + materials + colors + lighting + a "keep this" instruction. That last clause is what stops the model from rearranging your walls.

Step 3: Refine with follow-up edits

The first output is rarely the final one, and that's fine. Nano Banana handles conversational follow-ups well. Try things like "make the sofa darker green," "add a large area rug," "change the wall art to abstract," or "make the lighting warmer, like evening." Change one thing at a time so you can see what each edit does. If a result drifts too far from your real room, re-upload the original photo and start the prompt fresh rather than editing the edited image repeatedly, which tends to compound distortions.

Step 4: Generate variations

To compare directions, run the same base photo with different style keywords: "industrial loft," "Japandi," "mid-century modern," "coastal." Save the ones you like. This is a cheap way to figure out what you actually want before you spend money on real furniture or paint.

Honest pros and cons for interior design

Here's the straight talk, because a tutorial that only lists upsides isn't useful.

What it does well:

• It preserves room structure better than most image models, so redesigns feel like your room.
• It responds to natural-language follow-ups, so iterating is conversational rather than technical.
• It's genuinely fast for exploring lots of looks before committing.

Where it gets frustrating:

• Prompting is a skill. Getting consistent, realistic results takes trial and error, and small wording changes can swing the output a lot.
• Geometry can drift. Straight lines, perspective, and proportions sometimes bend, especially on busy or wide-angle photos.
• It invents details. Furniture it generates may not correspond to anything you can actually buy, so treat outputs as inspiration, not a shopping list.
• No built-in style library. You have to know the vocabulary ("Japandi," "transitional," "boho") to steer it; there's no menu of curated looks.
• Consistency across runs is hard. Reproducing a specific result later, or keeping a series cohesive, takes effort.

If you enjoy tinkering and want maximum control, none of this is a dealbreaker. If you just want a great redesign without learning prompt craft, read on.

Or skip the prompting: use a purpose-built app

The reason general tools feel fiddly for interior design is that they're general. They weren't built around the specific job of "show me my room in a new style." RoomGPT is, and it runs on the same class of Gemini model under the hood, tuned and constrained specifically for room redesign so you don't have to write any prompts at all.

The flow is deliberately boring in the best way: take a photo of your room, tap a style, and get a redesign in seconds. Instead of guessing the right keywords, you pick from 100+ interior design styles that are already dialed in, from modern to farmhouse to coastal to industrial. Want to see exactly how the broader process works end to end? Our AI interior design guide covers it in depth.

It's tuned per room type too, so the results respect what a space is actually for. There are dedicated flows for redesigning your living room and your bedroom, which means the model leans toward layouts and furnishings that make sense for each. You get the structure-preserving strength of Nano Banana without the part where you have to coax it with carefully worded prompts and "keep the windows" clauses.

The honest trade-off: a purpose-built app gives you less granular, free-form control than raw prompting. If you want to type an unusual one-off instruction, a general Gemini tool is more flexible. But for the everyday goal of "make my room look great, fast," a focused tool gets you there with far less friction and far fewer disappointing first drafts.

The bottom line

Nano Banana is a legitimately strong tool for reimagining a room, and the steps above will get you real results: upload a good photo, write specific style-plus-materials prompts, refine one change at a time, and generate variations to compare. Just go in knowing it rewards patience and prompt practice, and that it'll occasionally bend a wall or invent a sofa.

If that sounds like more effort than you want for a redesign, the same underlying technology is already packaged for you. RoomGPT is free, works on iPhone and Android, and turns a single photo into a styled redesign in seconds, no prompting required. Snap a photo of the room you want to change, pick a style, and see it transformed. Download RoomGPT free and redesign your first room today.