Interior design with Runway Gen-4 References: a step-by-step prompt guide

This guide explains how to use Runway's Gen-4 Image and Gen-4 References tools to visualize different furniture and upholstery alternatives through a single interior photo. The "Designing Interiors" use case featured in Runway's official documentation focuses on producing realistic and consistent compositions by adding furniture references to a single room image.

What you'll learn

By following this article, you'll learn how to use an interior photo as a reference, add separate furniture or object images to it, guide the composition with bounding box annotations, and refine results with text prompts.

Requirements

• A Runway account with sufficient credit balance (Gen-4 Image costs 8 credits per image at 1080p resolution, 5 credits at 720p)

• Tool mode from the left menu, Image tab at the top

• Gen-4 Image or Gen-4 Image Turbo selected from the model dropdown

• The relevant icon in the generation panel enabled to turn on the References feature

• A naturally and evenly lit room photo to use as a reference, plus separate furniture/object images

Step-by-step process

1. Upload the interior reference

First, drag a clear, well-lit photo of the room you want to design into the References panel. This image will form the foundation of the entire composition, and the new furniture will be integrated into this scene.

2. Add furniture images as separate references

Since a maximum of three references can be used in one generation, upload images of objects like the armchair, table, or rug you want to add alongside the room photo as separate references. Then describe both the room and the objects within the same prompt:

generate a realistic photograph of the living room from [img_1] with the armchair from [img_2] and the coffee table from [img_3]. keep the original wall color and natural daylight. add a patterned area rug beneath the furniture

This prompt aims to place the new furniture into the scene while preserving the atmosphere of the room photo. Clearly specifying old furniture you want removed beforehand improves the result.

3. Clean up the background of furniture images

If your object photos have a cluttered background, first use these images alone as a reference to simplify the background:

remove the background from this armchair image and place it in front of a solid white background, keep the lighting and shadows realistic

Object images with a clean background give more consistent results when integrated into the room in the next step.

4. Guide the composition with a bounding box

To clarify where in the room a specific piece of furniture should go, draw a simple rectangle on the room photo and add a short label next to it, for example writing "sofa" by the window. This annotated image can be used without any additional text prompt; however, adding a short description to clarify style and material detail is helpful:

place a modern linen sofa inside the marked rectangle, matching the wood tones and daylight already present in the room

5. Make major changes with a text prompt

If the first result isn't as dramatic as you expected, try again by adding more detail and bolder descriptions to the prompt. For example, describing wall color, material texture, and light temperature more explicitly can substantially change the outcome.

Common mistakes

• Uploading reference objects with complex backgrounds that obscure the original surface or patterns; this can cause the model to confuse the object with the background.

• Requesting too many changes at once in the same prompt; starting simple and adding detail gradually gives more predictable results.

• Writing prompts longer than the 1000-character limit; prompt length in Gen-4 Image is restricted to this limit.

• Trying to exceed the reference limit (maximum three); for more, separate iterations should be used, saving previous outputs as new references.

What this means for architecture and interior architecture workflows

This technique offers a practical interim solution for interior designers and architecture firms wanting to prepare quick concept presentations from a site photo. Being able to show clients multiple furniture and upholstery alternatives photorealistically, without physically moving furniture or doing 3D modeling, can speed up the presentation process. However, the outputs don't replace technical drawing or rendering software in terms of scale, perspective, and material accuracy, making them more suitable for early-stage idea presentations or marketing visuals. Due to credit-based pricing, projects requiring many iterations need cost planning.

Next steps

You can try uploading the interior image you created to Runway's video tools to add camera movement, or repeat the same technique with different style references (for example, a different brand or period aesthetic) to multiply design alternatives.

Source and license

This guide has been adapted into English from the "Advanced References Use Cases," "Creating with Gen-4 Image References," and "Creating with Gen-4 Image" guides published in Runway's official help center; the sample prompts have been rewritten specifically for the architecture/interior scenario based on the techniques described in these guides.