What is Architectural CGI?

Architectural CGI stands for computer-generated imagery produced from a 3D model of a proposed building. The process begins with the architect's CAD or BIM file, which a visualisation studio imports into a 3D application such as 3ds Max, SketchUp, or Revit. The studio then adds materials, assigns textures to walls, windows, roofing, and paving, sets up artificial and natural lighting to match the intended season and time of day, places a virtual camera, and renders the scene using a physically accurate lighting engine such as Corona or V-Ray.

The finished image is a still photograph of a building that does not yet exist. UK studios typically deliver exterior street views showing the front elevation in context, interior room sets showing finished kitchens, living spaces, or commercial fit-outs, aerial context shots showing the development in relation to surrounding streets and landmarks, and animation flythroughs that move through or around the scheme. A single project brief may require two to twelve images depending on the scope of the work.

CGI differs from a rendering only in terminology. Rendering is the computational step in which the 3D software calculates light bouncing between surfaces and produces a pixel-by-pixel image. CGI is the finished asset. In practice the two terms are used interchangeably in the UK architectural and property sector. Both refer to the same product: a photoreal or stylised image of a proposed building produced from a digital model.

For residential extensions, new-build houses, and commercial developments, CGI replaces hand drawings and traditional perspective sketches as the standard way of communicating design intent. Planners, investors, buyers, and end users can read a CGI at a glance in a way that requires no technical knowledge of drawing conventions. A well-produced CGI of a kitchen extension shows the client not just the floor plan but how the space will feel when the light changes through the day, how the materials work together, and whether the proportions are right before a single brick is laid.

The quality of architectural CGI varies significantly between studios. At the low end, a quickly produced image may show correct geometry but crude materials, flat lighting, and an unconvincing surrounding context. At the high end, a verified view produced to RICS guidance standards is indistinguishable from a photograph of the completed building. For planning and marketing purposes, the level of quality required depends on the audience: a public consultation image needs to be clear and unambiguous; a developer's sales brochure needs to be aspirational and photographic in quality.